A clear picture of non-domestic floor spaces in London was difficult to obtain, which again was surprising. There are primarily three main sources of statistics we could draw from:
- Valuation Office Agency (VOA),
- Display Energy Certificates (DEC)
- Non-domestic Energy Performance Certificates (EPC).
The different databases cover different non-domestic buildings: the VOA statistics consist of buildings that pay business rates, EPCs cover buildings for sale or rent, and DECs are of public buildings.
- VOA ~ 250,000 entries
- DEC ~6,500 entries
- EPC ~65,000 entries
Whilst we can assume most commercial buildings pay business rates, the VOA figures do not capture all non-domestic buildings. The statistics aggregates the floor spaces into 4 main categories, offices, retail, industrial and other. Referring to the initial release notes on VOA’s business floorspace statistics, building categories such as local authority schools, hospitals, hotels, cinemas etc. have been excluded altogether.
In an attempt to summarise all the non-domestic floor areas in London with a more detailed breakdown of usage categories, we pulled together data from various sources. We found the classification of business usage was not well-defined or standardised between datasets. For example, EPCs use planning classes whilst DECs use their own classifications. This made it difficult to consolidate and identify overlaps.
Nevertheless we had a go at creating a complete picture of London, and the biggest floor area types appear to be in the order of:
- Office ~ 27 million m2
- Industrial ~ 16 million m2
- Retail ~ 15 million m2
- Education ~ 13 million m2
- Health ~ 4 million m2
However, we are still not certain whether we have managed to capture all the non-domestic floor areas in London from the various sources. Interestingly, when looking at the proportion of DECs as representation of non-domestic floor areas in London, we find them to be under-sampled in certain categories as illustrated below.
Since DECs are the only publicly available source of real energy data we have for non-domestic buildings, this has significant implications to our analysis. Clearly, they are not representative of the proportions of non-domestic building stock in London, particularly in the top 3 floor area types in office, retail and industrial buildings.