Changes to Part L and the implications
for heavyweight buildings
Tom De Saulles
The Concrete Centre
Specifying Low Carbon Buildings
Southbank Centre
7 October 2010
0
100
200
300
400
1970 2002 2006 2010 2013 2016
heat
loss
(W/K)
Heat loss from
an average UK home
0
100
200
300
400
1970 2002 2006 2010 2013 2016
Base
year
0
100
200
300
400
1970 2002 2006 2010 2013 2016
Base
year
+275%
heat
loss
(W/K)
Heat loss from
an average UK home
BRE Innovation Park
Brookwood farm, Woking
September 2010.
Code level 5, ICF construction.
(William Lacey Group)
Currently being updated
for Part L 2010, 2013
& 2016.
0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100
6. Weather comp. + WWHR + FGHRS + PV (2 kWp)
5. Weather comp. + WWHR + FGHRS + PV (1kWp)
4. Weather comp. + WWHR + FGHRS
3. Weather comp. + WWHR
2. Weather comp.
1. No additional features
2010 (25%) 2013 (44%) 2016 (70%)
Basic fabric spec.Walls: 0.25, floor: 0.18, roof: 0.13
windows: 1.5, air permeability: 5.0
Y-value: 0.08
% improvement over Part L 2006
Meeting 2010, 2013
targets for Part L1(detached house)
0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100
6. Weather comp. + WWHR + FGHRS + PV (2 kWp)
5. Weather comp. + WWHR + FGHRS + PV (1kWp)
4. Weather comp. + WWHR + FGHRS
3. Weather comp. + WWHR
2. Weather comp.
1. No additional features
Basic fabric spec.
Enhanced fabric spec.
2010 (25%) 2013 (44%) 2016 (70%)
Walls: 0.25, floor: 0.18, roof: 0.13
windows: 1.5, air permeability: 5.0
Y-value: 0.08
Walls reduced to 0.2
Y-value reduced to 0.05
% improvement over Part L 2006
Meeting 2010, 2013
targets for Part L1(detached house)
0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100
6. Weather comp. + WWHR + FGHRS + PV (2 kWp)
5. Weather comp. + WWHR + FGHRS + PV (1kWp)
4. Weather comp. + WWHR + FGHRS
3. Weather comp. + WWHR
2. Weather comp.
1. No additional features
Basic fabric spec.
Enhanced fabric spec.
Govt. fabric energy efficiency spec.
2010 (25%) 2013 (44%) 2016 (70%)
Walls: 0.25, floor: 0.18, roof: 0.13
windows: 1.5, air permeability: 5.0
Y-value: 0.08
Walls reduced to 0.2
Y-value reduced to 0.05
Walls: 0.18, windows: 1.4, floor: 0.18
roof: 0.13 air permeability: 3.0, Y-value: 0.05.
% improvement over Part L 2006
Meeting 2010, 2013
targets for Part L1(detached house)
Flue gas heat recovery
(about £600 for smaller dwellings)
• Zenex Gas Saver
• Ravenheat Energy Catcher
• Alpha Flowsmart
Waste water heat recovery
(from about £200)
• Recoh-vert
• Recoh-tray
• Enviroharvest
• Warmit (AK Industries),
0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100
6. Weather comp. + WWHR + FGHRS + PV (2 kWp)
5. Weather comp. + WWHR + FGHRS + PV (1kWp)
4. Weather comp. + WWHR + FGHRS
3. Weather comp. + WWHR
2. Weather comp.
1. No additional features
Basic fabric spec.
Enhanced fabric spec.
+ Waste water heat recovery
% improvement over Part L 2006
2010 (25%) 2013 (44%) 2016 (70%)
Meeting 2010, 2013
targets for Part L1(detached house)
Govt. fabric energy efficiency spec.
0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100
6. Weather comp. + WWHR + FGHRS + PV (2 kWp)
5. Weather comp. + WWHR + FGHRS + PV (1kWp)
4. Weather comp. + WWHR + FGHRS
3. Weather comp. + WWHR
2. Weather comp.
1. No additional features
Basic fabric spec.
Enhanced fabric spec.
+ Waste water heat recovery
+ Flue gas heat recovery2010 (25%) 2013 (44%) 2016 (70%)
Meeting 2010, 2013 & 2016
targets for Part L1(detached house)
% improvement over Part L 2006
Govt. fabric energy efficiency spec.
Weather comp. = weather compensator
WWHR = waste water heat recovery
FGHR = Flue gas heat recovery
■ Basic fabric spec. ■ Enhanced fabric spec.
■ 2016 zero carbon fabric spec. ■ Enhanced 2016 zero carbon fabric spec.
Part L: 2010 (25%) 2013 (44%) 2016 (70%?)
Flat, mid-storey (50m
2)
0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100
6. Weather comp. + WWHR + FGHRS + PV (2 kWp)
5. Weather comp. + WWHR + FGHRS + PV (1kWp)
4. Weather comp. + WWHR + FGHRS
3. Weather comp. + WWHR
2. Weather comp.
1. No additional features
End terrace, 2-storey (61 m
2)
0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100
6. Weather comp. + WWHR + FGHRS + PV (2 kWp)
5. Weather comp. + WWHR + FGHRS + PV (1kWp)
4. Weather comp. + WWHR + FGHRS
3. Weather comp. + WWHR
2. Weather comp.
1. No additional features
Mid terrace, 2-storey (61m
2)
0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100
6. Weather comp. + WWHR + FGHRS + PV (2 kWp)
5. Weather comp. + WWHR + FGHRS + PV (1kWp)
4. Weather comp. + WWHR + FGHRS
3. Weather comp. + WWHR
2. Weather comp.
1. No additional features
End terrace,
3-storey (125m2)
0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100
6. Weather comp. + WWHR + FGHRS + PV (2 kWp)
5. Weather comp. + WWHR + FGHRS + PV (1 kWp)
4. Weather comp. + WWHR + FGHRS
3. Weather comp. + 100mm cylinder insulation + WWHR
2. Weather comp. + 100mm cylinder insulation
1. No additional features
Mid terrace,
3-storey (125m2)
0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100
6. Weather comp. + WWHR + FGHRS + PV (2 kWp)
5. Weather comp. + WWHR + FGHRS + PV (1 kWp)
4. Weather comp. + WWHR + FGHRS
3. Weather comp. + 100mm cylinder insulation + WWHR
2. weather compensator + 100mm cylinder insulation
1. No additional features
Detached,
2-storey (127m2)
0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100
6. Weather comp. + WWHR + FGHRS + PV (2 kWp)
5. Weather comp. + WWHR + FGHRS + PV (1kWp)
4. Weather comp. + WWHR + FGHRS
3. Weather comp. + 100mm cylinder insulation + WWHR
2. weather comp. + 100mm cylinder insulation
1. No additional features
% reduction in CO2 emission over Part L1A 2006
% reduction in CO2 emission over Part L1A 2006
% reduction in CO2 emission over Part L1A 2006
% reduction in CO2 emission over Part L1A 2006
% reduction in CO2 emission over Part L1A 2006
% reduction in CO2 emission over Part L1A 2006
Main findings
Part L1 2010 compliance:
• U-value for external walls, around 0.2 – 0.25 W/m2K
• Air permeability, around 5 m3/(h.m2)
• Renewables are not necessary, but enhancements to services are.
Main findings
Part L1 2010 compliance:
• U-value for external walls, around 0.2 – 0.25 W/m2K
• Air permeability, around 5 m3/(h.m2)
• Renewables are not necessary, but enhancements to services are.
Part L1 2013 compliance:
• Renewables can still be avoided, but a much higher level of fabric performance is needed.
• Alternatively, could use 2010 fabric performance and about 1 kW of PV.
Main findings
Part L1 2010 compliance:
• U-value for external walls, around 0.2 – 0.25 W/m2K
• Air permeability, around 5 m3/(h.m2)
• Renewables are not necessary, but enhancements to services are.
Part L1 2013 compliance:
• Renewables can still be avoided, but a much higher level of fabric performance is needed.
• Alternatively, could use 2010 fabric performance and about 1 kW of PV.
Part L1 2016 compliance:
• Need to meet or exceed the Govt. fabric energy efficiency standard. 2 - 3 kW of PV also needed.
This is the thermal capacity of the first
100mm, or up to the first insulating
layer, if this occurs first.
Measured by the ‘K-value’ (KJ/m2/K)
Introduction of thermal mass into Part L1
100mm
Sandwich panel,Up to 230 kJ/m2K
Solid masonry,Up to 190 kJ/m2K
Woodcrete block,Up to 145 kJ/m2K
Brick & block,Up to 190 kJ/m2K
Hemcrete block,Up to 135 kJ/m2K
Insulating clay block,Up to 65 kJ/m2K
Frame construction 2 x plasterboard,Up to 18 kJ/m2K
Frame construction1 x plasterboard,Up to 9 kJ/m2K
Block partition,Up to 100 kJ/m2K
Stud partition,Up to 9 kJ/m2K
How much thermal mass
do floors and walls have?
Hollow coreupper floor, up to 120/160 kJ/m2K
Beam & blockupper floor, up to120/40 kJ/m2K
Timber upper floor, up to 9/18 kJ/m2K
Insitu-concreteground floor,up to 140 kJ/m2K
Beam & blockground floor,up to 110 kJ/m2K
Timber ground floor,up to 20 kJ/m2K
Arup/Concrete Centre thermal properties tool
Sun at midday17º - 40º
South
Heating season: daytime
Heating season: night-time
EXAMPLE:
Highly insulated, airtight semi-detached house with efficient heating and controls.
What difference can thermal mass
make in SAP 2009?
RESULT:
• Moving from low to high thermal mass reduces emissions by about 3-4%
• This is roughly the same as changing the external wall U-value from 0.2 to 0.15
New full fill insulation system
Achieves a U-value of 0.17 - 0.18 with a 100mm cavity
Summertime performance / overheating
• The Zero Carbon Hub is calling for
an improved overheating check that
must be passed by all new homes.
Summertime performance / overheating
• The Zero Carbon Hub is calling for
an improved overheating check that
must be passed by all new homes.
• The check should take account of
future climate change.
• It should also take proper account of
night cooling and thermal mass.
Free passive design tool (currently under development)
Part L2 (2010)
New drivers for passive cooling
• 25% reduction in emissions required by Part L2
Part L2 (2010)
New drivers for passive cooling
• 25% reduction in emissions required by Part L2
• 23% increase in the assumed CO2 emissions from electricity (Part L1 and L2)
Part L2 (2010)
New drivers for passive cooling
• 25% reduction in emissions required by Part L2
• 23% increase in the assumed CO2 emissions from electricity (Part L1 and L2)
• New limits for solar gain in Part L2
Part L2 (2010)
New drivers for passive cooling
• 25% reduction in emissions required by Part L2
• 23% increase in the assumed CO2 emissions from electricity (Part L1 and L2)
• New limits for solar gain in Part L2
• 25 - 60% increase in the cost of electricity expected by 2016 (Ofgem)
Part L2 (2010)
New drivers for passive cooling
• 25% reduction in emissions required by Part L2
• 23% increase in the assumed CO2 emissions from electricity (Part L1 and L2)
• New limits for solar gain in Part L2
• 25 - 60% increase in the cost of electricity expected by 2016 (Ofgem)
• Possible relaxation of peak internal temperature in
BCO specification (from 22°C to 25°C)
Flat slab with natural ventilation Coffered slab & underfloor ventilation
Hollowcore slab (Termodeck®) Water-cooled slab
Manchester University
Business School
Completion: 2011
Architect: Feilden Clegg Bradley
Precast, lattice girder floors with integral water cooling pipes.
Woodland Trust HQ, Lincolnshire
Completion: Autumn 2010
Architect: Feilden Clegg Bradley
Key messages:
• Compliance with Part L1 in 2010, 2013 & 2016 does not present any
particular issues for masonry/concrete housing.
Key messages:
• Compliance with Part L1 in 2010, 2013 & 2016 does not present any
particular issues for masonry/concrete housing.
• Heat recovery systems can help with 2010 and 2013 compliance and
avoid the need for costly renewables.
Key messages:
• Compliance with Part L1 in 2010, 2013 & 2016 does not present any
particular issues for masonry/concrete housing.
• Heat recovery systems can help with 2010 and 2013 compliance and
avoid the need for costly renewables.
• SAP now includes thermal mass, and shows a year-round round benefit
in highly insulated and airtight heavyweight dwellings.
Key messages:
• Compliance with Part L1 in 2010, 2013 & 2016 does not present any
particular issues for masonry/concrete housing.
• Heat recovery systems can help with 2010 and 2013 compliance and
avoid the need for costly renewables.
• SAP now includes thermal mass, and shows a year-round round benefit
in highly insulated and airtight heavyweight dwellings.
• The dwelling overheating check in SAP is likely to be revisited.
Key messages:
• Compliance with Part L1 in 2010, 2013 & 2016 does not present any
particular issues for masonry/concrete housing.
• Heat recovery systems can help with 2010 and 2013 compliance and
avoid the need for costly renewables.
• SAP now includes thermal mass, and shows a year-round round benefit
in highly insulated and airtight heavyweight dwellings.
• The dwelling overheating check in SAP is likely to be revisited.
• There is likely to be a move from air-conditioning to passive cooling
solutions in many new, non-domestic buildings.
Thank you