Dataset Overview
This dataset details the potential for a property/building to have retrofit insulation installed, including how much insulation is required based off the geometry of the building.
The list of residential properties included in the dataset has been taken from Ordnance Survey (OS) AddressBase, including those classified as detached, semi-detached, terraced, self-contained flats and HMOs. Insulation measures included are cavity wall, external wall, roof and floor.
Domestic EPC certificates are combined with geospatial data from OS (OS MasterMap Topography and OS MasterMap Building Heights) to determine the existing energy efficiency and geometry of the property. Descriptions of the building envelope from its EPC have been simplified to include whether an element is currently insulated (Insulated/uninsulated), not suitable for insulation (Not applicable) or currently unknown (Unknown).
Properties which don’t have an EPC, or where the current level of insulation cannot be determined from the EPC default to unknown. ONS currently estimate EPCs to cover around 60% of housing stock in England and just under 60% in Wales. Not applicable cases describe where a building element is not suitable for a particular type of insulation.
For example, if a property is deemed to have solid brick walls, it cannot have cavity wall insulation installed.
Figure: EPC Ratings per Property (dark green = A, light green = B, yellow = C, orange = D, dark orange = E, black = No Data).
Assumptions
Geometric information for a property is based off it’s building footprint, rather than on a premise-by-premise level. This means in the case of self-contained flats or HMOs, floor areas and wall areas are for the whole building/block
Building area is the area of the building polygon, rather than total useable floor area
Wall area is the external wall perimeter multiplied by the height of building; height is taken as the building’s eave height or the lowest point at where the roof meets the vertical walls. The perimeter of external walls is determined geospatially by measuring the length of the building’s perimeter which doesn’t intersect/overlap with any other building polygon (Total building polygon perimeter - interior wall perimeter). This is illustrated below in figure 1.
Figure: Exterior wall perimeter determined through spatial analysis
Sources
Fields
Field Name | Field Description |
UPRN | Unique Property Reference Number |
EPC Rating | Currently energy rating ‘A’ through ‘G’ (where A is the most energy efficient and G is the least energy efficient). Taken from EPC record. |
Insulation - Cavity Wall | Insulated/Uninsulated/Unknown/Not applicable
Current cavity wall insulation inferred from EPC description |
Insulation - External Wall | Insulated/Uninsulated/Unknown/Not applicable
Current external wall insulation inferred from EPC description |
Insulation - Roof | Insulated/Uninsulated/Unknown/Not applicable
Current roof insulation inferred from EPC description |
Insulation - Under Floor | Insulated/Uninsulated/Unknown/Not applicable
Current floor insulation inferred from EPC description |
Wall Area [m^2] | The estimated external wall area [m^2] requiring insulation, used to plan under floor and roof insulation, based on the building polygon. |
Building Area [m^2] | The estimated building footprint area [m^2], used to plan under floor and roof insulation, based on the building polygon. |