Building regulations - new non-domestic buildings - modelling of proposed energy improvements: research report

Research to identify potential improvements in energy and emissions performance for new non-domestic buildings. Produced in support of proposed improvements to energy standards for new buildings within Scottish building regulations in 2021.



2 Except for radiant heating in top-lit spaces.

3 The user also has the option to input the kWpeak value to define the PV array size as an alternative to inputting area and panel type. However, neither input option allows the user to define the inverter efficiency or the temperature coefficient of the panel among other key variables.

4 Excluding system delivery losses.



7 U-values here are expressed as being in the vertical plane as is the convention under Section 6 2015. To align to changes to BS443 and associated standards it is proposed that the new Section 6 standard should express rooflight U-values standards in the horizontal plane.

8 Except for run-around coiler for which this the Eco-Design Directive stipulates a minimum efficiency of 68%.

9 The Welsh Part L 2020 analysis is still ongoing at the time of writing.

10 BEIS cost data gathered through the MCS scheme shows that capital cost per kilowatt falls as PV array size increases.

11 The Welsh Part L 2020 analysis is still ongoing at the time of writing.

12 Whilst utility companies are mandated to cooperate with reasonable requests for connection to their infrastructure this requirement does not extend to unorthodox uses of their property such as SSHPs. However there are examples of this technology being successfully deployed in Scotland.

13 Karlsson, Fredrik, Monica Axell, and Per Fahlén. 2003. “Heat Pump Systems in Sweden - Country Report for IEA HPP Annex 28.” Borås, Sweden: SP Swedish Technical Research Institute.

14 Simon Rees and Robin Curtis 2014. “National Deployment of Domestic Geothermal Heat Pump Technology: Observations on the UK Experience 1995–2013” Institute of Energy and Sustainable Development, De Montfort University. GeoScience Ltd.

15 i.e. the current Section 6 2015 minimum standard for ASHPs providing DHW.

16 This is distinct from cost-effectiveness for the building occupants/owners which is a measure of the return on investment in PV.

17 The carbon emission factor for these fuels is much lower than gas but as there is less difference between the primary energy factors for these fuels, the primary energy metric is of more significance.

18 The allocation of PV to the notional building will be based on the actual building’s system for space heating; DHW systems will not affect this. Where the actual building uses a mixture of heat pumps and fossil fuels then the notional building PV allocation will be calculated on a pro-rata basis based on the applicable floor areas. Where a bivalent system is used then the PV area will be calculated based on the respective heat load share of the heat generating technologies.

19 Currie & Brown’s cost management team are currently delivering a wide range of projects across the whole of Scotland including for both public bodies and private developers.

20 These values are based on the proposed factors for gas and electricity and assuming that: a gas CHP providing 75% of the annual load with the reminder being provided by gas boilers. Thermal efficiency of CHP=41%, Electrical efficiency of CHP=37%, Boiler efficiency=90%, Delivery losses=15%. This is slightly different to the basis for the DHN in the 2015 Section 6 requirements but is typical practise for new networks and aligned to other standards.

21 Valuation of energy use and greenhouse gas emissions for appraisal (April 2019).

22 Costs increases may be outside the described range for highly bespoke designs; however, these buildings are typically more expensive to construct and so the relative impact on build costs may be similar or potentially smaller than for more typical buildings.



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