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| Development of new homes in Glasgow by CCG Homes, Installation by Arc-Tech |
New regulations have been published for Part L building regulations in England.
Let's take a quick look at how they compare to Scotland, where almost all new homes now come with solar panels.
The building regulations work by defining a specification for a 'Notional Dwelling' - read this article for more detail of how it works
In the table below I have shown a selection of the more significant requirements for each. It is evident that not only do both Notional Houses include solar PV, but that the England requirement is much higher.
Housebuilders do not have to build the Notional House specification, but they must equal or exceed its performance. The scope for reducing the solar provision by increasing the insulation performance of building elements such as walls, roofs and windows (collectively often referred to as fabric measures) is limited in the new English regulations, which equal or exceed the fabric requirements in Scotland.
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‘Notional Dwelling’
Summary Specification Selected
Requirements |
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Scotland
2015 (Gas Package) |
England 2021 |
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U Values in
W/m2K |
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|
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External Walls |
0.17 |
0.18 |
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Floors |
0.15 |
0.13 |
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Roofs |
0.11 |
0.11 |
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Doors |
1.40 |
1.00 |
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Windows |
1.40 |
1.20 |
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Air
Permeability |
7 m3/h.m2
at 50Pa |
5 m3/h.m2
at 50Pa |
|
Heating |
Gas boiler
89% efficiency |
Gas boiler
89.5% efficiency |
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Heat Emitter
Type |
Regular
radiators |
Low
temperature heating 55°C flow |
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Heat Recovery |
Instantaneous
Waste Water 45% efficient |
Instantaneous
Waste Water 36% efficient |
|
Solar PV in
kWp |
Smaller of (a) Total
floor area (m2) x 0.01 (b) 0.3 x
roof area based on 30 degree roof pitch x 0.12 |
40% of
dwelling floor area/6.5 |
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Example solar
PV for 85m2 house with two floors |
0.85kWp |
2.6kWp |
