REEPS 4/3
SHCS paper
A baseline of historical emissions for energy demand in the domestic sector
Introduction
1. New energy standards in the owner occupation and private rented sector will contribute to the reduction in energy demand and emissions in the domestic sector. Thus, a baseline of housing stock ’s energy demand is necessary to compare the effectiveness of the new standards against historical emissions in the residential sector, so that it is possible to gauge progress, in line with the
Climate Change (Scotland) Act 2009. In this document we present two potential data sources:

Scottish Household Condition Survey (SHCS)

National Atmospheric Emissions Inventory (NAEI)
2. This note defines both data sources and suggests to follow the same approach as for the Energy Efficiency Standard for Social Housing (EESSH), using SHCS as the baseline for past emissions.
SHCS
3. The Scottish Government uses information about dwellings and their occupants drawn from the Scottish House Conditions Survey (SHCS) to model energy use based on the existing heating and hot water systems, appliance and lighting use.
Using standard (UK) emissions factors for each fuel, modelled energy consumption is converted to carbon emissions.
4. Only occupied domestic dwellings are surveyed by the SHCS.
5. Modelling is carried out using an implementation of the BRE’s Domestic Energy
Model (BREDEM) based on a standard heating regime for all households.
Outputs of the model provide a consistent back series to 1991, which is comparable between years, groups and individual households.
6. These emissions are based on modelled consumption and do not account for the behaviour of occupants. This means that the information produced is a property of the building fabric and energy systems in isolation.
7. SHCS emissions figures are not calibrated against external emissions inventories. Estimates of carbon emissions are therefore useful for internal comparison between surveyed groups only.
NAEI
8. NAEI estimates energy demand in the residential sector by fuel types. For example, gas use estimates for Scotland are derived from the UK Department of
Energy and Climate Change (DECC) sub-national energy statistics, which represents a breakdown of gas by Local Authority for the domestic and nondomestic sector. The share of Scottish gas consumption derived from total DECC sub-national energy statistics in gas is applied to the Digest of UK Energy
Statistics (DUKES) annual domestic gas in order to calculate gas consumption in
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REEPS 4/3
SHCS paper
Scotland for the residential sector. DUKES is a dataset containing final energy consumption in the UK compiled with information provided by energy companies.
9. NAEI is based on energy consumption. It includes the domestic sector and small energy users in the non-domestic sector such as small offices. However, it is not possible to know what is the percentage of small offices accounted in the domestic sector.
10. NAEI is revised annually due to improvements on the data collection and the methodology. This revision changes the baseline retrospectively.
11. Electricity consumption is not included in the residential sector since emissions from electricity are recorded in the production side and apportioned to the energy sector.
12. NAEI is managed by the UK Department for Environment, Food and Rural Affairs
(DEFRA). Updates of the inventory are completed in collaboration with a consortium of private consultancies (Aether and RICARDO
– AEA).
Conclusion
13. To quantify the effect of the Regulation of Energy Efficiency in Private Owned and Rented Housing (REEPS) in reducing emissions, and thus the contributions to the reduction in targets, we need to compare the emissions before and after the intervention with previous emissions.
14. SHCS and NAEI can be used to set out the historical emissions of the residential sector.
15. SHCS is modelled by analysts in CAS which have ownership of the methodology and the data. This is a clear advantage. For example, ownership of the data will allow us to recalculate the baseline removing the social sector and concentrating on the private sector.
16. For that reasons, we advise to use figures of emissions in the residential sector estimated from SHCS.
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