Part L2 of the Building Regulations 2000 have been
amended in accordance with governments manifesto
commitment to reduce CO2 emissions in the UK. The
amendments come into force on 1st April 2002. Their
aim is to reduce the energy load required for heating
and cooling buildings. The principle amendments in
relation to the building envelope performance include:
• Increased levels of thermal insulation to all envelope
assemblies.
• New “U” value calculation procedure which is more
onerous than the previous methodology.
• Finite element analysis method to assess the
impact of thermal bridging, including joints, junctions
and fasteners, throughout the external envelope (Linear
thermal transmissions - Y-value and calculation of
whole building’s a-value).
• Calculation method to assess condensation and
mould growth risk (surface temperature f-factor).
• Increased requirement for the thermal upgrading of
the building envelope during refurbishment/change of
use works.
• Emphasis on effective insulation continuity within the
external envelope.
• Introduction of infra-red thermographic surveys.
• Introduction of mandatory air pressurisation testing
of all new non-domestic buildings over 1,000m2 floor
area to comply with maximum permissible leakage
rates.
• New requirements for design, commissioning and
operation of building services.
PRINCIPLE AMENDMENTS TO PART J
(SCOTLAND)
• To ensure the effective measures for the
conservation of fuel and power are incorporated in a
building.
• Increased levels of thermal insulation to all envelope
assemblies.
• Building fabric constructed to minimise thermal
bridges and gaps in the insulation layer(s), junctions
and between building elements.
• Limiting of air infiltration and leakage.
• New requirements for design, commissioning and
operation of building services.
2
3
Contents
Introduction & Reason for Changes 4
The Building Regulations (England & Wales) 2000 5
Part L2: Conservation of Fuel & Power
The Building Standards (Scotland) Regulations 1990 11
Part J: Conservation of Fuel & Power
Complying with Building Regulations & Standards - Parts L2 & J 15
Post Construction Inspection & Testing 16
Thermographic Inspection & Air Pressurisation Testing Specifications 17
Climate Change Levy (CCL) Tax 18
HVAC Plant & Energy Operating Cost Reduction Service 19
Kingspan Construction Solutions Service 22
Parts L2 & J Compliance Checklist 23
Bibliography & Useful References 24
Construction Solutions & Details 25
Thermal Bridging & Overall Heat Loss Areas 26
Air Leakage Risk Areas 27
4
Introduction
INTRODUCTION & REASON FOR CHANGES
World-wide concern regarding climate change and
the impact which greenhouse gas emissions have on
the environment have encouraged governments to
act. Buildings are major energy users and therefore
construction is a targeted area for change across
Europe and particularly within the UK.
By international agreement the UK will reduce
greenhouse gas emissions by 12.5% below 1990
levels by the period 2008-2012. In addition the UK
government is committed to reduce the levels of CO2
by 20% by 2010.
Building energy use, specifically heating, cooling and
lighting accounts for approximately half of the UK’s
greenhouse gas emissions. Improving energy
efficiency is therefore critical and construction is
required to play a major part in achieving the
government’s targets.
The Regulation amendments aim to improve the
thermal performance of buildings by approximately
25-30% with a corresponding reduction in CO2
emissions.
The aim of the Building Regulations 2000 (England &
Wales) Approved Document L2 and Building
Standards (Scotland) Regulations 1990 - Part J
(Conservation of Fuel and Power) is to maximise the
contribution that building regulations can make to
meeting the Governments CO2 reduction targets,
whilst maintaining proportionality, design flexibility and
avoiding excessive costs and technical risks. One of
the purposes of building control is to implement the
regulations concerning the conservation of fuel and
power.
Energy efficient building design and construction will
be the dominant industry issue for the first decade of
the 21st Century.
The government’s commitment to reducing CO2
emissions involves an integrated design and
construction approach requiring the building fabric
and HVAC services to comply with Part L2 and
Part J thereby achieving improved thermal, air
leakage standards and HVAC energy efficiency
benchmarks. This also minimises the impact of the
Climate Change Levy (CCL) tax.
Reducing energy loss from buildings will be achieved
in England and Wales through amendments to
Part L2 and in Scotland to Part J. These new
Regulations will initially impact new buildings but will
also apply to existing buildings through requirements
to refurbish and upgrade such buildings to the new
regulatory requirements.
The new regulatory approach is to reduce building
energy consumption by tackling five principal
areas:
i) Through significantly higher insulation
performance standards.
ii) Through the introduction (for the first time) of
building envelope air leakage limits Part L2.
ii) Provision of insulation continuity.
iv) Limiting the effect of thermal bridging.
v) Post construction thermal imaging and air
infiltration testing Part L2.
IMPLEMENTATION TIMETABLE
Building Regulations Part L2 (England & Wales)
i) will come into force 1st April 2002.
ii) all building works after that date will have to
comply with the new regulations unless:
– full plans have been approved unconditionally by
the local authority before that date.
– a building notice has been given, a
commencement notice has been given and
building work has started on site before
1st April 2002.
• Definition of Commencement of Building Works
– excavation of foundations.
– preparation of ground for raft foundations.
– vibrofloatation piling, boring for piles or pile
driving.
• Works not Considered to Constitute
Commencement of Building Works
– removal of vegetation or topsoil.
– removal or treatment of contaminated soil.
– excavation of trial holes.
– dynamic compaction.
– general site servicing works (roadways,
drainage, etc).
Building Standards Part J (Scotland)
i) will come into force 4th March 2002.
ii) Part J standards is applicable where the building
warrant is lodged from 4th March 2002.
The aim of this guide is to assist property
investors, designers and the construction team to
provide energy efficient industrial and commercial
buildings which fully comply with Part L2 and Part J,
using Kingspan’s insulated roof and wall cladding
systems.
5
Building Regulations 2000
Part L2: Conservation of Fuel & Power (England & Wales)
BUILDING DESIGN
General
To achieve energy efficiency in practice, the building
envelope and HVAC services systems should be
integrated at the design and construction stages.
Energy usage and efficiency benchmarks are to be
calculated so that energy performance of the building
can be monitored during its lifecycle.
The Approved Document L2 provides guidance on
meeting the requirements at each of these important
stages of procuring a building, whether it be a new
building, an extension or a refurbishment project. More
detailed guidance on energy efficiency measures can be
found in ‘CIBSE Guide Energy Efficiency in Buildings’.
HVAC installations have to include the inspection and
commissioning of the plant prior to project handover.
In large complex buildings, it may be sensible to consider
provisions for the conservation of fuel and power
separately for the different parts of the building in order to
establish appropriate measures for each area.
Design Methods
Three methods are permitted for demonstrating
compliance with the standard, all involve integration of
the design and construction of the building fabric
and the design and operation of HVAC services.
The methods are:-
1. an Elemental Method: This method considers the
performance of each aspect of the building
individually. To comply with the provisions of Part L, a
minimum level of performance should be achieved in
each of the elements. Some flexibility is provided for
trading off between different elements of the
construction, and between insulation standards and
heating system performance.
2. a Whole Building Method: This method
considers the performance of the whole building.
For office buildings, the heating, ventilation, air
conditioning and lighting systems should be capable
of being operated such that they will ‘emit no more
carbon’ per square metre per annum than a
benchmark based on the ECON 19 data. Alternative
methods are also provided for schools and hospitals.
3. a Carbon Emissions Calculation Method: This
method also considers the performance of the whole
building, but can be applied to any building type. To
comply with the provisions of Part L, the annual
carbon emissions from the building should be no
greater than that from a notional building that meets
the compliance criteria of the Elemental Method. The
carbon emissions from the proposed building and the
notional building need to be estimated using an
appropriate calculation tool.
Approved Document L2 contains a guide to the use of
all three compliance methods.
6
Building Regulations 2000
Part L2: Conservation of Fuel & Power (England & Wales)
THE ELEMENTAL METHOD
Metal clad industrial and commercial buildings are
generally constructed with insulated roof and wall
systems which are based on the Elemental Method
as indicated in the following information.
To comply with Part L2 the building envelope has to
provide certain minimum levels of insulation, and air
leakage performance, and the building services
systems have to meet defined minimum standards of
energy efficiency.
To provide compliance the following design and
construction requirements have to be met:
i) Comply with regulatory U-values
ii) The building fabric should be constructed so
that there are no significant thermal bridges or gaps
in the insulation layer(s) within the various elements
of the fabric, at the joints between elements, and at
the edges of elements such as those around
windows and door openings.
iii) Buildings should be reasonably airtight to avoid
unnecessary space heating and cooling demand
and to enable the effective performance of
ventilation systems.
iv) Designers, constructors and installers must
ensure that the construction quality complies with
the regulations.
v) Infrared thermography inspection confirmation
that the insulation is continuous over the whole
building envelope including junctions.
vi) Air pressurisation testing confirmation that the
building complies with the regulatory standards.
vii)Testing of building work – The local authority may
make such tests of any building as may
be necessary to establish whether it complies with
Part L2.
7
Building Regulations 2000
Part L2: Conservation of Fuel & Power (England & Wales)
Part L2 Compliance Requirements Effective from 1st April 2002
Standard U-Values of Construction Elements (U-Value W/m2K)
• Flat roof (not exceeding 10°) or roof with integral insulation 0.25
• Walls, including basement walls 0.35
• Floors, including ground floors and basement floors 0.25
• Windows, roof windows and personnel doors (area weighted average 2.20
for the whole building), glazing in metal frames3
• Windows, roof windows and personnel doors (area weighted average 2.00
for the whole building), glazing in wood or PVC frames3
• Rooflights4,5 2.20
• Vehicle and similar large doors 0.70
Boundary Wall
& Valley Gutters
0.25
(For pre melt
applications 0.35)c
Rooflights
2.20d
Roofs
0.25
External
Side Walls
0.35
Overhanging Eaves
or Soffits
0.35
(When soffits are
part of a floor 0.25)
Floors
0.25
Vehicle - Large Doors
0.70
Windows & Personnel Doors
2.00a/2.20b
a If windows have wood or PVC frames c For pre melt gutter specifications obtain d Rooflights may be permitted up to 12% of roof area at 3.0W/m2K
b If windows have metal frames building control approval at design stage by using the ‘Whole building’ or ‘Carbon emission’ method of
calculation, however, there is a significant risk of condensation.
Standard U-Values (W/m2K) for Insulated Metal Roof & Wall Cladding Systems –
Elemental Method Part L2
Notes to table:
1. Any part of a roof having a pitch greater or equal to 70° can be considered as a wall.
2. For the sloping parts of a room-in-the-roof constructed as a material alteration, a U-value of 0.30W/m2K would be reasonable.
3. Display windows, shop entrance doors and similar glazing are not required to meet the standard given in this table.
4. This standard applies only to the performance of the unit excluding any upstand. Reasonable provision would be to insulate
any upstand, or otherwise isolate it from the internal environment.
5. For the purposes of Approved Document L2, a roof window may be considered as a rooflight.
Elemental Method - Roof and Wall Solutions
Approved Document L2 Compliance – Kingspan Roof and Wall Systems – CFC Free
Roof Systems – U-Values Product Thickness Product Thickness Air Leakage*
Flat roof or roof with integral
KS1000 RW - TS 80mm KS1000 LP - CR
80mm
5m3/h/m2 insulation 0.25 W/m2K
Rooflights 2.20 W/m2K 5m3/h/m2
Wall Systems – U-Values Product Thickness Air Leakage*
0.35 W/m2K KS600/900/1000 - MR/EB/FL-S/CX/WV/MM 70mm (0.35 W/m2K) 5m3/h/m2
0.35 W/m2K KS900/1000 Optimo 70mm (0.35 W/m2K) 5m3/h/m2
0.35 W/m2K KS1000 RW 60mm (0.35 W/m2K) 5m3/h/m2
Notes: *To achieve a building air leakage performance of 10m3/h/m2 @ 50 Pa, the air leakage performance of the roof/wall system has to be lower to allow for leakage at
openings/junctions. Air leakage solutions are available for 2m3/h/m2, consult Kingspan Technical Services Department.
(0.25 W/m2K) (0.25 W/m2K)
8
Building Regulations 2000
Part L2: Conservation of Fuel & Power (England & Wales)
BUILDING ENVELOPE AIR LEAKAGE
Air Tightness Standards
Part L2: Requires an air barrier to minimise air
leakage and infiltration through the building fabric –
air leakage tests to be carried out in accordance
with CIBSE TM 23.
The test standards are:
i) up to 30th September 2003, 11.5m3/h/m2 at
50pa.
ii)from 1st October 2003, will be 10m3/h/m2 at
50pa.
Part L2: Air movement through extraneous air paths
must be limited as far as is reasonably practical.
For the first time a mandatory air leakage standard is
required, to achieve this the following measures are
necessary:
i) Buildings should be reasonably airtight to comply
with the air leakage standard to avoid unnecessary
space heating and cooling demand and to enable
the effective performance of ventilation systems.
ii) The need to provide for adequate ventilation for
health (Part F) and adequate air for combustion
appliances (Part J) should be particularly taken into
account.
iii) A way of meeting the requirement would be to
incorporate sealing measures to achieve the
performance standard given in ‘Certificates &
Testing’ (page 9). Some ways of achieving
satisfactory air tightness include:
a) providing a reasonably continuous air barrier in
contact with the insulation layer over the whole
thermal envelope (including separating walls).
Special care should be taken at junctions between
elements and around door and window openings.
Satisfactory design details and installation practice
are described in the robust details publication.
Guidance for the design of metal cladding and
roofing systems to minimise air infiltration is given in
the Kingspan Design Guide and the MCRMA
Technical Paper No.14.
b) sealing gaps around service penetrations.
c) draught-proofing external doors and windows.
Maximum Area of Openings unless Compensation Measures are taken
Windows and Rooflights
Doors % Exposed % of
Building Type Wall Area Roof Area
• Places of assembly, offices and shops 40 20
• Industrial and storage buildings 15 20
• Vehicle access doors As required
Note: Care should be taken in the selection and installation of glazed systems to avoid the risk of condensation. Guidance can be obtained from BRE Report 262.
MAXIMUM AREAS OF WINDOWS,
DOORS & ROOFLIGHTS
Provision should be made to limit the rate of heat loss
through glazed elements of the building.
One way of demonstrating compliance is if the total
area of windows, doors and rooflights does not
exceed the values given in the table below, unless
compensated for in some other way. Rooflights up
to 12% of the roof area may be permitted with a
U-value of 3.0W/m2K by applying the ‘Whole
building’ or ‘Carbon emission’ methods of
calculation.
However, the internal temperature of double skin
rooflights will be significantly lower, which can
cause condensation risk.
9
Building Regulations 2000
Part L2: Conservation of Fuel & Power (England & Wales)
Airtightness
Air barriers should be installed to minimise air
infiltration through the building fabric. In this case too,
certificates or declarations should be provided
or obtained by the person carrying out the work,
stating:
a) for buildings of any size, that the results of air
leakage tests carried out accordance with CIBSE
TM 23 are satisfactory; or
b) alternatively for buildings of less than 1000m2
gross floor area, that appropriate design details and
building techniques have been used, and that the
work has been carried out in ways that can be
expected to achieve reasonable conformity with
the specifications that have been approved for the
purposes of compliance with Part L2.
Certificates & Testing
Certificates or declarations such as those mentioned
in above may be accepted by building control bodies
as evidence of compliance. The building control body
will, however, wish to establish, in advance of the
work, that the person who will be giving the
certificates or declarations is suitably qualified.
If using the CIBSE TM 23 pressure test procedures
as the means of showing compliance:-
a) With effect from 1 October 2003, reasonable
provision would be test results showing that the air
permeability does not exceed 10m3/h/m2 at an
applied pressure difference of 50pa.
b) In the period up to and including 30 September
2003, reasonable provision in the event that initial
test results are unsatisfactory would be the results
of further tests carried out after appropriate
remedial work.
i) an improvement of 75% of the difference
between the initial test result and the target
standard of 10m3/h/m2 at 50pa; OR, if less
demanding
ii) a performance no worse than 11.5m3/h/m2 at
50pa
Other Regulatory Requirements
(refer to Approved Document L2)
• avoiding solar heating
• heating system efficiency
• space heating control systems
• hot water systems and controls
• insulation of pipes, ducts and vessels
• lighting efficiency and controls
• air-conditioning and mechanical ventilation
systems
• standards for schools and hospitals
• inspection and commissioning of the building
services systems
BUILDING LOG-BOOK
The owner or occupier of the building should be
provided with a log book giving details of the installed
building services plant and controls, their method of
operation and maintenance, and other details that
collectively enable energy consumption to be
monitored and controlled. The information should be
provided in summary form, suitable for day-to-day
use. This summary could draw on or refer to
information available as part of other documentation,
such as the Operation and Maintenance manuals and
the Health and Safety file.
The building log book is to include the measured air
permeability of the building.
For further details refer to Approved Document L2.
INSTALLATION OF ENERGY METERS
To enable owners or occupiers to measure their
actual energy consumption, the building engineering
services should be provided with sufficient energy
meters and sub-meters. The owners or occupiers
should also be provided with sufficient instructions
including an overall metering strategy that show how
to attribute energy consumptions to end users and
how the meter readings can be used to compare
operating performance with published benchmarks.
Reasonable provision would be to enable at least
90% of the estimated annual energy consumption of
each fuel to be accounted for.
For further details refer to Approved Document L2.
10
Building Regulations 2000
Part L2: Conservation of Fuel & Power (England & Wales)
MATERIAL ALTERATIONS
‘Material alterations’ are defined as follows:-
“An alteration is material for the purposes of these
Regulations if the work, or any part of it, would at any
stage result-
(a) in a building or controlled service or fitting not
complying with relevant requirement where previously
it did: or
(b) in a building or controlled service or fitting which
before the work commenced did not comply with a
relevant requirement, being more unsatisfactory in
relation to such a requirement.”
Roof Insulation
When substantially replacing any of the major
elements of a roof structure – providing insulation to
achieve the U-value for new buildings.
Floor Insulation
Where the structure of a ground floor is to be
substantially replaced – or re-boarded, providing
insulation in heated rooms to the standard for new
buildings.
Wall Insulation
When substantially replacing complete exposed walls
or their external renderings or cladding or internal
surface finishes, or the internal surfaces of separating
walls to unheated spaces, providing a reasonable
thickness of insulation.
Sealing Measures
When carrying out any of the above work, including
reasonable sealing measures to improve airtightness.
Controlled Services & Fittings
When replacing controlled services and fittings,
following the guidance in Part L2.
MATERIAL CHANGES OF USE
‘Material changes of use’ are defined as follows:-
...for the purposes of these Regulations, there is a
material change of use where there is a change in the
purposes for which or the circumstances in which a
building is used, so that after that change – see Part
L2 for definitions.
Roof Insulation
When substantially replacing any of the major
elements of a roof structure – providing insulation to
achieve the U-value considered reasonable for new
buildings.
Floor Insulation
Where the structure of a ground floor is to be
substantially replaced – providing insulation in heated
rooms to the standard considered reasonable for new
buildings.
Wall Insulation
When substantially replacing complete exposed walls
or their external renderings or cladding or internal
surface finishes, or the internal surfaces of separating
walls to unheated spaces, providing a reasonable
thickness of insulation
Sealing Measures
When carrying out any of the above work, including
reasonable sealing measures to improve airtightness.
Controlled Services & Fittings
When replacing controlled services and fittings,
following the guidance in Part L2.
Before Refurbishment
After Refurbishment with KS1000 RW
11
Building Standards 1990
Part J 6th Amendments: Conservation of Fuel & Power (Scotland)
INTRODUCTION
The Scottish Executive has agreed to work in
partnership with the UK Government in achieving a
goal of a 20% reduction in UK carbon dioxide
emissions by 2010. This goal is significantly beyond
and so more challenging than the UK’s international
target to reduce greenhouse gas emissions by 12.5%
in the first commitment period (2008-2012).
BUILDING STANDARDS CHANGES
The construction industry has a major role to play in
the conservation of fuel and power. Energy use in
buildings is a major source of carbon dioxide
emissions which contribute to climate change.
The intention of Part J changes is to ensure that
effective measures for the conservation of fuel and
power are incorporated in a building.
It contains energy conservation provisions for the
building fabric and the building services.
Tighter building regulations is the best option for
delivering improved energy efficiency in new building
works, as it ensures that action is taken for the benefit
of both the individual, investor and occupiers and to
support the national carbon reduction targets.
Building regulations ensure that the Government sets
standards, and that private agents are able to achieve
these standards in the most cost-effective way they
can find, stimulating efficiency and innovation.
Improvements in energy efficiency have been
demonstrated to be one of the most efficient ways of
reducing carbon emissions.
The primary benefit of the new regulations will be to
contribute towards the achievement of the UK
Government’s international commitments on carbon
emissions. These commitments contribute to the
international efforts to reduce the impacts of climate
change.
PART J AMENDMENTS
AND INTRODUCTION TIMETABLE
The Scottish Executive Part J amendments will be
implemented from 4th March 2002 on approved
building warrants.
A building other than a building in purpose groups 2
to 7 must have provision for conservation of fuel and
power in accordance with one of the three following
methods:
i) the Elemental Method
ii) the Heat Loss Method (refer to Standards)
iii) the Carbon Emissions Calculation Method
(refer to Standards)
In addition to requirements for insulation of the fabric
there are requirements for building services, air
conditioning, mechanical ventilation and artificial
lighting.
ELEMENTAL METHOD
The Elemental Method is the most widely used
procedure to determine insulated metal roof and wall
systems.
12
Building Standards 1990
Part J 6th Amendments: Conservation of Fuel & Power (Scotland)
Part J Compliance Requirements Effective from 4th March 2002
Maximum U-Values of Exposed Building Elements when using the Elemental Method (Note1)
Exposed Building Element Maximum U-Value (W/m2K)
• Roof (all roof slopes) 0.25
• External Wall (Note 2) 0.30
• Floor 0.25
• Windows, personnel doors and rooflights (area weighted 2.20
average for the whole building) (Note 3), glazing in metal frames (Note 4)
• Windows, personnel doors and rooflights (area weighted 2.00
average for the whole building) (Note 3), glazing in wood or PVC frames
• Vehicle access and similar large doors (Note 5) 0.70
Notes to table:
1. When an element is exposed to the outside via an unheated space, the unheated space may be disregarded or the U-value of the element
calculated using BS EN ISO 13789: 1999.
2. Solid area of element only (i.e. excluding windows, doors and rooflights).
3. For method of calculation, see Appendix E.
4. Metal framed windows have slimmer frames and therefore provide a passive solar benefit, justifying a less onerous U-value standard.
5. No requirement where for operational reasons doors have to be left open when building is in use.
Roofs
0.25
External
Side Walls
0.30
Floors
0.25
Vehicle - Large Doors
0.70
Windows & Personnel Doors
2.00a/2.20b
Standard U-Values (W/m2K) for Insulated Metal Roof & Wall Cladding Systems –
Elemental Method Part J
a Windows, personnel doors and rooflights b Windows, personnel doors and rooflights c For pre melt gutter specifications obtain
(area weighted average for the whole (area weighted average for the whole building control approval at design stage
building), glazing in wood or PVC frames building), glazing in metal frames d Rooflights may be permitted up to 12% of roof area at 3.0W/m2K,
by using the ‘Whole building’ or ‘Carbon emission’ method of
calculation, however, there is a significant risk of condensation.
Elemental Method - Roof and Wall Solutions
Part J Standards Compliance – Kingspan Roof and Wall Systems – CFC Free
Roof Systems – U-Values Product Thickness Product Thickness
0.25 W/m2K KS1000 RW - TS 80mm (0.25 W/m2K) KS1000 LP - CR 80mm (0.25 W/m2K)
Rooflights 2.20 W/m2K
Wall Systems – U-Values Product Thickness
0.30 W/m2K KS600/900/1000 - MR/EB/FL-S/CX/WV/MM 80mm (0.30 W/m2K)
0.30 W/m2K KS900/1000 Optimo 80mm (0.30 W/m2K)
0.30 W/m2K KS1000 RW 70mm (0.30 W/m2K)
Boundary Wall
& Valley Gutters
0.25
(For pre melt
applications 0.35)c
Rooflights
2.20d
Overhanging Eaves
or Soffits
0.30
(When soffits are
part of a floor 0.25)
13
Building Standards 1990
Part J 6th Amendments: Conservation of Fuel & Power (Scotland)
Maximum Percentage Areas of Windows, Doors and Rooflights
Windows and Rooflights
Doors % Exposed% of
Purpose Group Wall Area 1 Roof Area
• 2 30 20
• 3, 4, 5 40 20
• 6, 7 15 20
Note: 1. Excluding vehicle access and other similar large doors, and shop display windows at an excess level, for which there is no limit.
The specified building elements must have areas of
windows, doors and rooflights not more than those
prescribed in the table to this standard.
Rooflights up to 12% of the roof area may be
permitted with a U-value of 3.0W/m2K by applying
the ‘whole building’ or Carbon emission methods of
calculation. However, the internal temperature of
double skin rooflights will be significantly lower,
which may cause condensation risk.
LIMITING THERMAL BRIDGING AT
JUNCTIONS AND AROUND OPENINGS
The building’s fabric must be constructed to
minimise thermal bridges and gaps in the insulation
layer(s):
a) within the various building elements
b) at the junctions between building elements
c) at the edges of building elements (e.g. around
window and door openings)
The requirements as regards minimising thermal
bridges and gaps in the insulation, will be met by:
a) constructing the building in accordance with
Building Research Establishment (BRE) Report,
BRE 262: “Thermal insulation, Avoiding risks”,
Second Edition, 1994/2002 or
b) demonstrating by calculation that equivalent
performance to a) has been achieved.
LIMITING AIR LEAKAGE
Air leakage into or out of a building through
extraneous air paths must be limited as far as is
reasonably practical.
The requirements as regards minimising
extraneous air leakage paths in the buildings fabric
will be met by constructing the building in
accordance with BRE Report BRE 262: “Thermal
insulation, Avoiding risks”, Second Edition, 1994,
including,
a) sealing the gaps between dry linings and
masonry walls at the edges of window, door and
roof space openings, and at the junctions between
walls, floors and ceilings
b) sealing vapour control membranes in timber
framed and other framed panel constructions; and
c) sealing at service penetrations of the fabric or
around boxing for services; and
d) fitting draught seals to the openable parts of
windows, doors and rooflights; and
e) sealing around joist ends built into the inner leaf
of external cavity walls
14
Building Standards 1990
Part J 6th Amendments: Conservation of Fuel & Power (Scotland)
BUILDING SERVICES
Heating System Efficiency
The heating system of a building must be designed
and installed to make efficient use of energy for the
conservation of fuel and power. (refer to Standards)
Space Heating Controls
(refer to Standards)
Artificial Lighting
(refer to Standards)
Air Conditioning, Mechanical Ventilation
A building incorporating air conditioning or
mechanical ventilation must be designed and
constructed so that:
a) the form and fabric of the building do not result in
a requirement for excessive installed capacity of
cooling equipment; and
b) fans, pumps, refrigeration equipment and other
components are reasonably efficient and
appropriately sized to have no more capacity for
demand and standby than is necessary; and
c) there are appropriate means of managing,
controlling and monitoring the operation of equipment
and systems.
The requirements for energy efficiency of air
conditioning and mechanical ventilation, will be met.
(refer to Standards)
Commissioning of the Building Services
* The building services installation required to comply
with this Part must –
a) be capable of operating at the manufacturer’s
specified efficiency; and
b) incorporate adequate provisions for testing and
commissioning to be carried out satisfactorily.
* Written information must be provided for the
building’s occupier on the installed building services
plant and controls required to comply with Part J,
their method of operation, state of maintenance,
and details forecasting annual energy consumption
for the building.
The requirements as regards the commissioning of
the building services, will be met by certifying that
commissioning of the installation has been done in
accordance with CIBSE Commissioning Codes and
BSRIA Commissioning Guides.
The requirements as regards the provision of
information for energy efficient operation will be met
by a self-contained building log-book containing the
following details –
a) a schedule of the floor areas of each of the
building zones categorised by environmental
servicing type (e.g. air-conditioned, naturally
ventilated); and
b) the purpose of the individual building services
systems; and
c) the location of the relevant plant and equipment;
and
d) the installed capacities (input power and output
rating) of the services plant; and
e) simple descriptions of the operational and control
strategies of the energy consuming services in the
building; and
f) operating and maintenance instructions that
include provisions enabling the specified performance
to be sustained during occupation.
15
Complying with Building Regulations &
Standards - Parts L2 & J
Fulfiling compliance with Part L2 and Part J requires
building designers and constructors to integrate the
design and construction of the building envelope
and services to achieve lowest new build costs,
optimise energy usage efficiency and reduce
operating costs.
The introduction of higher performance building
envelope systems also delivers the following
commercial benefits:
• Reduces capital cost of HVAC plant.
• Lowers energy usage consumption, reduces
operating costs and minimises Climate Change Levy
(CCL) tax.
• Enhances property rental, asset and
re-sale values.
• Increases the change of use flexibility.
• Establishes precise specification(s) for insulation,
air leakage, HVAC services and energy efficiency
usage standards and benchmarks.
• Enables property investors and occupiers to
assess financial and commercial payback benefits at
design stage.
Building Envelope Design, Specification and
Post Construction Testing
Buildings can only comply and operate to Part L2 and
Part J if they are designed, constructed and
commissioned to a high standard.
Design and construction needs to be monitored to
ensure that construction quality matches design
specification and will therefore pass post
construction handover, thermographic inspection
and air pressurisation testing.
DESIGN, SPECIFICATION, CONSTRUCTION
QUALITY & TESTING CHECKLIST
The changes to Part L2 and Part J increase the risk
of having to remedy design and/or construction
quality defects should the building not comply with
the regulatory standards. This imposes additional
risk on the design and construction teams which
has obvious client consequences in the event of
non compliance.
The following checklist is to assist designers and
constructors to achieve a ‘first time right’
Part L2 and Part J building envelope.
Insulation and Thermal Continuity
• Thermal - (U-value) design, specification and
construction quality requirements:
➤ cold or warm construction system and
U-value reliability assessment.
➤ certainty of insulation continuity .
➤ limiting gaps or missing insulation.
➤ limiting thermal or cold bridges.
➤ limiting age degradation of insulant U-value due to
settlement, sagging or thinning.
➤ limiting interstitial cavity condensation.
➤ limiting air movement through the insulant.
➤ limiting night sky radiation condensation risk.
➤ assess impact on insulation U-values and
thickness due to thermal bridging caused by
compression under spacer bar and impact of
purlin/rail spacing variations.
➤ provide compliant specification (Part L2 - MCRMA
Paper No.14) and construction details for
junctions, joints, penetrations and abutment
interfaces.
➤ assess build quality and workmanship risks.
➤ determine construction quality standards and site
supervision levels.
➤ post construction thermographic inspection
implementation.
Air Tightness
• Air leakage specification and construction quality
requirements
➤ determine air leakage performance of building and
envelope system and assess design, construction
and compliance risks.
➤ assess envelope system options and associated
risks
➤ assess air/vapour sealant methods, materials,
specifications and installed construction quality
risks.
➤ provide compliant specification (Part L2 - MCRMA
Paper No.14) and construction details for
junctions, joints, penetrations and abutment
interfaces.
➤ assess build quality and workmanship risks.
➤ determine construction quality standard and site
supervision levels.
➤ post construction air pressurisation testing
implementation.
Site Construction Quality
➤ site workmanship and installation quality must
match the design specification to comply with
Part L2 and Part J.
➤ site management, supervision and operatives
must have clear specification, construction details,
installation/assembly method instructions and
necessary training to achieve ‘first time right’
workmanship quality.
Post Construction Inspection and Testing
Further to the usual quality inspection, the following
are required under Part L2 prior to project handover:
➤ infrared thermographic inspection.
➤ air pressurisation testing.
16
Post Construction Inspection & Testing
THERMOGRAPHIC INSPECTION &
AIR PRESSURISATION TESTING
The introduction of infrared thermography
inspection and air pressurisation testing
requirements within Approved Document L2 to
confirm design and construction build quality prior
to project handover places significant demands on
the design and construction team(s) to ensure that
construction quality and workmanship matches the
approved design specification.
It is therefore essential that installation is carried out by
trained and experienced contractors and operatives,
that are well supervised and correctly follow the
project design specification and construction
drawings.
INSPECTION & TESTING SERVICE
Kingspan have formed an alliance with Building
Sciences Limited who are an independent and
approved building sciences company to provide
infra-red and air pressurisation testing service.
This service is available directly through Building
Sciences Limited to any Kingspan clients, designers,
contractors or installers on a project specific
fee basis.
To obtain this service contact Building Sciences
Limited directly.
Infra-red thermography image
Air pressurisation testing equipment
Building Sciences Limited
The Forge, Home Farm,
Ardington,Wantage,
Oxon, OX12 8PN
Tel: 01235 835323
Fax: 01235 863220
www.buildingsciences.co.uk
Large building air pressurisation testing unit
17
Thermographic Inspection & Air Pressurisation
Testing Specifications
AIR PRESSURISATION
TESTING SPECIFICATION
On completion of the building, the contractor shall
undertake an air pressurisation test. The building
shall be designed and constructed to a maximum
allowable envelope air leakage rate of 10m3/hr/m2
at 50Pa pressure differential
Air Sealing Work
All sealing works required to ensure continuity of the
air barrier system must be carried out in accordance
with the design details and with materials approved
by the employer’s representative. Any variation to the
works involving air barrier continuity must be
approved by the employer’s representative. The
integrity, continuity and durability of the air barrier
system must be addressed at all junctions, joints,
penetrations, abutment interfaces or openings in the
external envelope.
Air Leakage Test Method
The contractor shall subject the building to a fan
pressurisation test in order to prove compliance with
the Specification. The test shall be undertaken in
accordance with CIBSE Technical Memorandum
TM23 - ‘Testing Buildings for Air Leakage’.
The maximum leakage rate specified refers to the
envelope area including solid ground floors. The
external envelope area shall be accurately calculated
by the testing organisation from scaled drawings
provided by the contractor prior to the test.
Procedure Should the Building Fail the
Pressurisation Test
Should the building fail to comply with the specified
maximum air leakage, the contractor shall be
responsible for undertaking the necessary air leakage
identification, remedial sealing works and further fan
pressurisation tests at their own cost until the
specification is achieved and demonstrated to the
employer’s representative.
It is recommended that the following procedures are
incorporated into design, tendering and construction
briefs/contracts.
INFRARED THERMOGRAPHIC
INSPECTION SPECIFICATION
On completion of the building, the contractor shall
undertake an infrared thermographic survey. The
aim of the survey is to prove acceptable insulation
continuity and identify any areas of thermal
deficiency which may require remedial attention.
Survey Requirements
The survey will be undertaken in accordance with the
relevant British Standard BS EN 13187: 1999.
The portable thermal imaging equipment used for the
survey must operate in either the long wave band
(8-14m) or a broad wave band (2-14m).
A minimum internal/external temperature differential of
10°C must exist at the time of the survey.
The envelope surface areas being surveyed must be
completely dry and should not have been subjected
to direct solar radiation for a period of 3 to 8 hours
prior to the survey (timescale depends on
construction type).
Survey Report
The survey findings must be included in a final report
which should include:
a) General description of the construction type.
b) The actual internal/external temperature differential
present at the time of the survey.
c) Typical calibrated coloured images of thermally
sound areas of construction within the building.
d) Calibrated coloured images of all thermal
anomalies identified with a brief description of the
probable reason for the anomaly.
e) Two full copies of the report including coloured
thermographic images shall be provided.
18
Climate Change Levy (CCL Tax)
The British Government introduced the Climate
Change Levy on all non-domestic energy use in April
2001.
The Climate Change Levy (CCL) is charged on all
energy supplied to industrial and commercial users,
as well as for agriculture, public administration and
other services. This means that the energy supplier
registers with, and pays the levy to, Customs and
Excise, not individual companies. Individual
businesses will pay the levy plus VAT through their
utilities bills.
The CCL is applied at different rates, depending on
the energy content of the different sources.
For instance:
• 0.43 p/kWh for electricity
• 0.15 p/kWh for gas
• 1.17 p/kilogram for coal
• 0.96 p/kilogram for liquid petroleum gas (LPG)
Climate Change Levy tax has typically increased
energy costs by 8-10% for businesses who have no
levy rebate arrangement.
It is not applied to any oils or oil based fuels – these
are already subject to other forms of tax, or energy
supplied to the domestic sector
For business users of these fuels, several exemptions
are allowed for. These include energy generated by
Combined Heat and Power (CHP) and electricity
generated from renewable sources.
All industrial energy use will be subject to the climate
change levy to varying degrees. However, the need
for industry to cut energy becomes imperative. By
reducing energy consumption, companies will
minimise the the impact of this tax. In particular,
energy intensive industries participating in Negotiated
Agreements will need to meet agreed targets for
improved energy efficiency, if they are to obtain a
rebate on the levy. Hence, companies will save
money, and see emission levels fall, which will in turn
reduce environmental impact, and sharpen
competitiveness.
Ten of the largest energy intensive trade associations
signed Memoranda of Understanding with the
Government in December 1999. These represent the
chemicals, cement, steel, glass, aluminium, nonferrous
metals, paper, foundries, food and drink and
ceramic sectors. This agreement states the energy
efficiency targets and the carbon or emissions targets
that each sector has agreed, in return for an 80%
CCL rebate. As part of the agreement the DTLR
provides for independent verification and offers
guidance and advice to CIA member companies.
Under an agreement made in 1997, the industry
agreed to improve energy efficiency by 20% over the
period 1990-2005. A 15% improvement has already
been proved through monitoring and auditing
programmes, and through exchanges of best
practice.
19
HVAC Plant & Energy Operating Cost
Reduction Service
Background
The introduction of Regulations Part L2 and
Standards Part J involves a new approach to
building design and construction, in particular
meeting clients energy efficiency usage and cost
benchmarks. Meeting these requirements can
often involve the design team in lengthy and costly
investigations to develop a cost-effective, energy
efficient design that complies with Parts L2 and J
and fulfils the clients energy performance brief.
Parts L2 and J encourage an integrated design
approach to the building envelope and services
which minimises energy usage levels to benchmark
standards.
Kingspan have introduced an energy efficiency
analysis package which enables downsizing of
HVAC plant costs which achieves optimum energy
efficiency usage and operating costs.
The Energy Impact of Building Envelope
Air Leakage
It is accepted by CIBSE that air leakage leads to the
single greatest percentage of heat loss from the
majority of new non-domestic buildings in the UK.
The energy load for leakage is a major constituent
part in the sizing of heating, cooling and ventilation
plant, but accurately assessing the impact of any
given envelope leakage rate is a complex process. To
overcome this the current practice is generally to use
‘rule of thumb allowances’ for plant design.
Kingspan and Building Sciences undertook computer
analysis on a series of typical building sizes and types
to establish the following:
• The obtainable capital cost savings on HVAC plant
within low envelope leakage buildings.
• The obtainable annual energy operating cost
savings from low envelope leakage.
• The obtainable CO2 emission reduction from low
envelope leakage.
The buildings analysed ranged from 5,000 to
20,000m2 floor area with internal air temperatures of
16°C, 19°C and 21°C. The buildings were
representative of typical warehouse, industrial, retail
and office units. The analysis was based on 1985
weather data for the Birmingham region and was
undertaken for buildings with both an urban and a
scattered windbreak exposure. Birmingham was
chosen as providing 'average' weather benchmark for
England and Wales. Weather data from the year 1985
was chosen as it is representative of a relatively cold
'recent' year.
The analysis compared identical buildings with
envelope leakage rates of 22 and 10.0m3/hr/m2 @ 50
Pa. This represents current typical building air leakage
norm and the proposed Part L2 regulatory
requirements.
The analysis summary includes HVAC plant, energy
operating cost savings and CO2 emission reductions
which are indicated in the following tables.
Payback Analysis Summary
5,000m2 Floor Area Buildings
HVAC Plant Cost Savings Energy Operating CO2 Emission
Internal Building Total Capital Floor Area Cost Savings Reductions
Terrain Temp Purpose Cost Saving Saving m2 (Kwh/annum) (kg/annum)
Urban 16°C
Warehouse/
£76,250.00 £15.25 62,117.068 15,373.974
Manufacturing
Warehouse/
Urban 19°C Manufacturing/ £76,250.00 £15.25 92,089.501 22,972.152
Retail
Urban 21°C
Office
£36,000.00 £7.20 115,514.490 28,589.836
(heating only)
Scattered
16°C
Warehouse/
£75,450.00 £15.09 74,934.960 18,546.403
windbreaks Manufacturing
Scattered
Warehouse/
windbreaks
19°C Manufacturing/ £75,450.00 £15.09 109,867.207 27,192.134
Retail
Scattered
21°C
Office
£36,000.00 £15.25 136,659.671 33,823.268
windbreaks (heating only)
20
HVAC Plant & Energy Operating
Cost Reduction Service
The calculation results confirm the very significant
environmental benefits which can be achieved from
the construction of low air leakage envelopes.
The level of obtainable HVAC plant capital cost and
energy operating cost savings is substantial. The
savings available far outweigh the additional cost of
constructing and testing low air leakage envelope
buildings and provide building investors and
occupiers with significant cost reduction advantages
at new build and throughout the operating lifecycle of
the building.
Payback Analysis Summary
10,000m2 Floor Area Buildings
HVAC Plant Cost Savings Energy Operating CO2 Emission
Internal Building Total Capital Floor Area Cost Savings Reductions
Terrain Temp Purpose Cost Saving Saving m2 (Kwh/annum) (kg/annum)
Urban 16°C
Warehouse/
£175,100.00 £17.51 105,264.733 26,053.021
Manufacturing
Warehouse/
Urban 19°C Manufacturing/ £175,100.00 £17.51 156,115.675 38,638.629
Retail
Urban 21°C
Office
£67,500.00 £6.75 195,886.853 48,481.996
(heating only)
Scattered
16°C
Warehouse/
£172,900.00 £17.29 126,472.652 31,301.981
windbreaks Manufacturing
Scattered
Warehouse/
windbreaks
19°C Manufacturing/ £172,900.00 £17.29 185,660.791 45,951.046
Retail
Scattered
21°C
Office
£67,500.00 £6.75 231,167.715 57,214.009
windbreaks (heating only)
15,000m2 Floor Area Buildings
HVAC Plant Cost Savings Energy Operating CO2 Emission
Internal Building Total Capital Floor Area Cost Savings Reductions
Terrain Temp Purpose Cost Saving Saving m2 (Kwh/annum) (kg/annum)
Urban 16°C
Warehouse/
£265,150.00 £17.67 176,821.004 43,763.198 Manufacturing
Warehouse/
Urban 19°C Manufacturing/ £265,150.00 £17.67 258,684.265 64,024.356
Retail
Scattered
16°C
Warehouse/
£262,600.00 £17.50 235,050.120 58,174.905 windbreaks Manufacturing
Scattered
Warehouse/
windbreaks
19°C Manufacturing/ £262,600.00 £17.50 240,060.231 59,414.907
Retail
20,000m2 Floor Area Buildings
HVAC Plant Cost Savings Energy Operating CO2 Emission
Internal Building Total Capital Floor Area Cost Savings Reductions
Terrain Temp Purpose Cost Saving Saving m2 (Kwh/annum) (kg/annum)
Urban 16°C
Warehouse/
£362,625.50 £18.13 202,296.984 50,068.503 Manufacturing
Warehouse/
Urban 19°C Manufacturing/ £362,625.50 £18.13 296,027.423 73,266.787
Retail
Scattered
16°C
Warehouse/
£352,725.50 £17.60 265,593.497 65,734.390 windbreaks Manufacturing
Scattered
Warehouse/
windbreaks
19°C Manufacturing/ £352,725.50 £17.60 384,468.405 95,155.930
Retail
21
HVAC Plant & Energy Operating Cost
Reduction Service
PROJECT SPECIFIC PAYBACK SERVICE
Kingspan can provide a project specific payback
analysis service. This service assesses the impact of
the building envelope air leakage on a specific
project. By comparing a typical construction with an
air leakage specification of 5 or 10m3/hr/m2 @ 50Pa.
The Analysis Results Include:
1 The maximum natural air change rate for the
building and the percentage of the year when this
will occur.
2 The overall energy impact of envelope leakage in
terms of kilowatt hours per annum.
3 The overall energy savings for the low air leakage
envelope construction.
4 The environmental benefits of the low air leakage
envelope construction in terms of CO2 emission
reductions.
The results of the analysis can then be utilised
by the client’s mechanical and electrical engineer to
undertake accurate HVAC plant downsizing design to
establish capital cost and energy usage savings.
For more information contact Kingspan Technical
Services Department on Tel: 01352 716101.
22
Kingspan Construction Solutions Service
Our Technical Hotline staff support investors,
designers and constructors with industry leading
experience, knowledge and expertise in providing
best practice construction solutions input and advice
on any project.
This includes all construction performance and
building physics issues, working details, model
specifications, lifecycle and siteworks/build method
information.
Our team of regionally based Sales Managers are
available to provide immediate customer and project
assistance.
HVAC PLANT & ENERGY OPERATING
COSTS PAYBACK SERVICE
We provide a comprehensive value added building
economics payback service which includes HVAC
plant downsizing, energy operating costs and CO2
emissions reductions.
LIFECYCLE PERFORMANCE
WARRANTIES
Kingspan provide project specific lifecycle warranties
which include external coatings, structural and
thermal performance guarantees.
For further information please contact Kingspan
Technical Services Department.
23
Parts L2 & J Compliance Checklist
Thermal and Insulation Continuity Performance Kingspan Solution
 Guaranteed U-Value lifecycle performance.
 Guaranteed insulation continuity.
 No gaps or missing insulation.
 No cavities within the system.
 No thermal or cold bridges.
 No age degradation of insulant U-Value due to settlement, sagging
or thinning.
 No interstitial cavity condensation.
 No air movement through the insulant.
 No night sky radiation condensation risk.
 No product specification changes due to purlin/rail centre dimensional variations.
 Kingspan designed construction solutions and details for junctions, joints,
penetrations and abutment interfaces comply with Parts L2 & J and
MCRMA Technical Paper No.14.
Air Tightness Performance
 Factory quality pre-engineered system manufactured to precise tolerances.
 Effective inter panel jointing.
 Impermeable metal faced, closed cell insulant system.
 Factory applied side lap air seals remove site workmanship quality risks.
 Internal liner profile facilitates reliable air seal application.
 Kingspan designed construction solutions and details for junctions, joints,
penetrations and abutment interfaces comply with Parts L2 & J and
MCRMA Technical Paper No.14.
Fire Performance
 - Building Regulation compliant and Property Insurer (LPCB & FM)
approved roof and wall systems.
Construction Quality
 Factory quality pre-engineered system supplied to project specific requirements.
 Single component simplicity.
 Simple installation – single fix operation.
 Kingspan provide Parts L2 & J contractor awareness, training and site
installation support service.
Post Construction Inspection & Testing
 Building Sciences Ltd provide thermographic inspection and air pressurisation
testing service and are available to Kingspan clients on a project fee basis.
Kingspan Warranty Package
 BBA certified roof systems (KS1000 RW - TS - LP/CR).
 Kingspan provide project specific lifecycle warranties which include external
coatings, structural, thermal and air leakage performance guarantees.
Kingspan Technical Services Department provide project specific construction solutions
for Parts L2 & J compliance - Call 01352 716101


 







 


 
24
Bibliography & Useful References
1. Kingspan Design Guide, The Architects & Designers
Guide to Construction and Good Practice.
2. Approved Document L2 Conservation of Fuel and
Power in Buildings other than Dwellings, October 2001
(England & Wales).
3. Building Standards 1990, Part J 6th Amendment:
Conservation of Fuel and Power (Scotland).
4. MCRMA Paper No.14 : Guidance for the Design of
Metal Roofing and Cladding to Comply with Approved
Document L2 : 2001.
5. Building Research Establishment (BRE) Report, BRE
262: “Thermal Insulation, Avoiding risks”, Second
Edition, 1994 or 2002 Edition.
6. DEFRA/DTLR Report: Limiting Thermal Bridging and Air
Leakage: Robust construction details for dwellings and
similar buildings. The Stationery Office, October 2001.
7. BS EN ISO 6946 : 1997 Building Components and
Building Elements – Thermal resistance – Calculation
method.
8. BRE IP 17/01 Assessing the Effect of Thermal Bridging
at Junctions and Around Openings. BRE, August 2001.
9. CIBSE Guide A3 Thermal Properties of Building
Structures. CIBSE, 1999.
10. BS EN 12524 : 2000 Building Materials and Products –
Hygrothermal properties – Tabulated design values.
11. BRE Information Paper IP 5/98 : Metal Cladding :
Assessing Thermal Performance.
12. BS EN ISO 10211-1 : 1996, Thermal Bridges in
Building Construction - Heat flows and surface
temperatures, Part 1. General calculation methods.
13. BS EN ISO 10211-2 : 1996, Thermal Bridges in
Building Construction - Heat flows and surface
temperatures, Part 2. Linear thermal bridges.
14. BS 5250 : 1989 British Standard Code of Practice for
Control of Condensation in Buildings.
15. BS EN ISO 13788 : 2001 : Hygrothermal Performance
of Building Components and Building Elements -
Internal surface temperature to avoid critical surface
humidity and interstitial condensation – Calculation
methods.
16. A Practical Guide to Infra-red Thermography for Building
Surveys, BRE Report 176, BRE 1991.
17. CIBSE Guide TM23 : 2000, Testing Buildings for Air
Leakage, CIBSE 2000.
18. BS EN 13829 : 2001 Thermal performance of buildings
– Determination of air permeability – Fan pressurisation
method.
19. BS EN12114 : 2000 Thermal performance of buildings
– Air permeability of building components and building
elements – Laboratory test method.
20. Pitts A.C. and Georgiadis S – Ventilation air flow through
window openings in combination with shading devices.
Proc. 15th AIVC Conf., (Buxton,1994).
21. Willis S., Fordham M., Bordass W. – Avoiding or
Minimising the use of Air Conditioning – General
Information Report 31 (Garston: Building Research
Energy Conservation Support Unit, 1995).
22. The Building Regulations Approved Document F:
Ventilation (London: HMSO, 1995).
23. Orme M., Liddament M. W. and Wilson A. – An Analysis
and Data Summary of the AIVC’s Numerical Data Base
TN44 (Coventry: Air Infiltration and Ventilation Centre,
1994).
24. Perera M. D. A. E. S., Turner C. H. C. and Scivyer C. R.
– Minimising Air Infiltration in Office Buildings, Report
265 (Garston: Building Research Establishment, 1994).
25. Martin A. and Pennycook K. – Control of Natural
Ventilation TN11/95 (Bracknell: Building Services
Research and Information Association, 1995).
26. Baker N. V. – Energy and Environment in Non-Domestic
Buildings (London: Royal Institute of British Architects,
1994).
27. CIBSE – Code for Interior Lighting (London: Chartered
Institution of Building Services Engineers, 1994)
28. Daylighting in Buildings – THERMIE maxibrochure
(Garston: Building Research Energy Conservation
Support Unit/OPET, 1994).
29. Energy Efficiency in Offices - Small Power Loads –
Energy Consumption Guide 35 (Garston: Building
Research Energy Conservation Support Unit, 1993).
30. Window Design Applications Manual AM2 (London:
Chartered Institution of Building Services Engineers,
1987).
31. BS 6375: Performance of Windows: Part 1: 1989
Classification of Weathertightness (including Guidance
on Selection and Specification) (London: British
Standards Institution, 1989).
32. Irvine G. – Sound insulation of open windows: novel
measures to achieve ventilation and sound insulation –
Proc. Institute of Acoustics, Volume 15 Part 8 pp249-
264 (1993).
33. CIBSE Building Services – The Design Process:
A Guide for Architects and Other Construction
Processes (describes the overall design process).
34. CIBSE Commissioning Code B: Boilerplant
(for information on measuring boiler efficiency).
35. CIBSE Commissioning Code C : Automatic Controls.
36. CIBSE Commissioning Code A: Air Distribution
Systems.
37. BSRIA Commissioning of Air Systems in Buildings.
38. HVCA DW/143 Practical Guide to Ductwork Leakage
Testing.
39. CIBSE Commissioning Code W: Water Distribution
Systems.
40. BSRIA Commissioning of Water Systems in Buildings.
25
Construction Solutions & Details
COMPLIANCE WITH APPROVED
DOCUMENTS PART L2 AND J
Effect of Thermal Bridging & Heat Loss - Part L2
Approved Document L2 requires that the building
fabric should be constructed so that there is no
significant thermal bridges or gaps in the insulation
layer(s) within the various elements of the fabric, at the
joints, junctions between elements such as those
around windows and door openings. It is also
necessary to account for any penetration of the
envelope by any details such as safety harness posts
or rafters which project to support a canopy, gutter or
overhanging eaves/gables and soffits.
It is necessary to consider both the risk of
condensation at each individual thermal bridge and
the effect of increased heat loss through thermal
bridges on the overall heat loss from the building.
Effect of Thermal Bridging & Heat Loss
Calculation Method - Part L2
(a) The severity of the thermal bridge, and the
assessment of risk of condensation or whether mould
growth is likely is determined by the f-factor which is
calculated by modelling the structure/detail.
(b) To calculate the contribution of the thermal
bridges to the overall heat loss of the whole building
is assessed by using the linear transmittance
(Y-value) and then following the procedures specified
in BRE IP17/01. If the total heat loss through the
thermal bridges is greater than 10% of that through
the plane areas, individual details must be modified to
reduce the loss through the bridges.
(c) The parameters needed to comply with Part L via
IP17/01 (the f-factor and the Y-value) are given in
report MCRMA Technical Paper No. 14, (Guidance
for the Design of Metal Roofing and Cladding to
Comply with Approved Document L2 : 2001) which
contains a range of details applicable to metal clad
buildings.
Two dimensional thermal modelling to calculate the ffactor
and the Y-value is also indicated.
(d) Responsibility for achieving the correct f-factor
and Y-values rests with the design and construction
teams. The person(s) responsible for achieving
compliance should provide a certificate that the
provisions meet the requirements of Part L2. Such
certificates or declarations should indicate the
appropriate design details and construction quality
that have been used in the work has been carried
out in ways that can be expected to achieve
reasonable conformity with the specifications that
have been approved for the purposes for compliance
with Part L2; or
that infra-red thermography inspections have shown
that the insulation is reasonably continuous over the
whole visible envelope.
Part J Requirements
There is no finite analysis method to establish f-factor
or Y-value required for Part J, however, all
construction junctions have to be supported by
robust thermal and air leakage design and
specification details which are then constructed to
correct build quality standards. See pages 12 to 16.
KINGSPAN CONSTRUCTION
SOLUTIONS AND DETAILS
We are currently undertaking finite element analysis
calculations to establish f-factor and Y-values for
junctions, joints, penetrations and abutment
interfaces and associated construction details.
This work will be completed and published shortly.
In the interim please contact our Technical Services
Department for project specific construction details
for Parts L2 and J on 01352 716101.
26
Thermal Bridging & Overall Heat Loss Areas
Parts L2 & J
To illustrate the relative effect of different components,
junctions and air leakage loss the following has to be
considered at design stage:
• Provide continuity of insulation at junctions, joints,
penetrations and abutment interfaces.
• Prevent missing insulation or gaps.
• Minimise thermal or cold bridges.
Part L2
• Assess impact of thermal bridging throughout
the building envelope, calculate linear thermal
transmissions - Y-value and calculation of whole
building’s a-value).
• Assess condensation and mould growth risk
(surface temperature f-factor).
Notional Industrial Building Indicating Thermal
Bridge Risk Areas
Walls
Corners
Brick/Block Junctions
Cills
Door Heads & Jambs
Windows/Curtain Wall
Heads, Jambs & Cills
Penetrations
Roofs
Eaves
Verges
Ridges
Rooflights
Internal Gutters
Penetrations
1
10
12
9
2
3
5
6
7
8
4
6m
40m
60m
1
2
3
4
5
7
8
9
10
11
12
6
TECHNICAL SUPPORT SERVICE
We are currently undertaking finite analysis
calculations to establish f-factor and Y-values for
junctions, joints, penetrations and abutment interfaces
and associated construction details.
This work will be completed and published shortly.
In the interim please contact our Technical Services
Department for project specific construction details for
Parts L2 and J on 01352 716101.
11
27
Air Leakage Risk Areas
Parts L2 & J
To illustrate the relative effect of different components,
junctions and air leakage loss the following has to be
considered at design stage:
• Limit air leakage loss within the envelope fabric
and at junctions, joints, penetrations and abutment
interfaces to comply with regulatory requirements.
• Roof and wall cladding air leakage will be required
to be less than that indicated in Part L2 as the
regulations refers to the whole building air leakage
level. i.e. including doors, windows, dado walls and
floor slab junctions.
• The air leakage performance of Kingspan’s roof
and wall panels is 5m3/hr/m2 when installed to
specification.