Supply chain advice pack: Property Data
Introduction
This advice pack is designed for the supply chain, installers and contractors to gain an understanding of what type of data you may need for a retrofit project, and where housing providers may hold this data within their systems and records. The quality and extent of data available will be dependent on the housing provider you are working with.
Published: March 2025
Contents
Scope of property data
Below is a list of the typical housing information data which a housing provider would hold. Depending on the housing stock and its location there may be other data sets that would be relevant to include.
- EPC / SAP assessment
- Property type
- Construction age
- Floor area
- Wall construction
- Wall insulation
- Roof type
- Roof insulation
- Space Heating fuel type
- Water heating fuel type
- On/off gas grid
- Tenure
- Conservation area
- National parks
- Areas of natural beauty (AONB)
- Listed/heritage properties
- Distribution network operator (DNO)
- Planned works
- Heat networks
Sources of property data
Given the range of property data available, it is unlikely that all data will be stored in a single location. Examples of locations for data are as follows:
Stock condition surveys
Stock condition surveys collect detailed information on the internal and external building components to determine the condition of the property. The condition information can be for compliance reasons and/or updating asset and financial records to know when key components may need to be replaced.
Data can be used for the reporting against the Decent Home Standard, which in turn can help to target properties that require immediate attention. Stock owners tend to commission stock condition surveys every five to ten years, but this may vary.
Stock condition surveys can be used to calculate the energy performance of a home using data collected from the surveys. The data may need processing through stock modelling software or a calculator tool (see ‘calculating energy performance’ for more information’).
Planned and cyclical maintenance records
Planned and cyclical maintenance programme information shows which properties are scheduled for improvements, what those works are and when they will take place.
Often stock owners will upgrade a particular component on many homes as part of a cyclical repairs and maintenance programme, e.g. roofs, boilers or doors because they can achieve economies of scale. It can also be useful to have many homes using the same specification of component technology for ease with ongoing maintenance and repairs.
Compliance records
Certain aspects of a property are required to have regular compliance checks (examples below). The information held in the compliance records can provide useful data on the property.
- Key compliance checks can include:
- Gas safety checks- which are an annual requirement for housing providers and will provide details of the make and model of any gas fired components within the property.
- Electrical safety checks-which are a 5-year requirement for housing providers and will provide details of electrical installations within the property, including the presence of any electrical heating systems.
Standard Assessment Procedure (SAP data)
EPC ratings are derived from SAP scores. SAP quantifies energy performance in terms of energy use per unit of floor area and are based on estimated annual energy use for space heating, hot water, ventilation and lighting.
Full SAP is required for new buildings under the building regulations.
RdSAP is the ‘reduced data’ version of SAP and is used in assessments of existing homes for Energy Performance Certificates (EPC). RdSAP uses some default data for certain data points where information is not as easy to collect (e.g., u-values for building fabrics). The assumptions embedded in RdSAP means that it is not as accurate as full SAP.
The RdSAP methodology is under review and there has been no announcement about when the new version will be released.
Energy Performance Certificate (EPC) data
An EPC gives a property an energy efficiency rating from A (most efficient) to G (least efficient) and is valid for 10 years. It also describes levels of insulation, the efficiency of heating and hot water systems and types of glazing and lighting.
It can be common for owner-occupied homes not to have an EPC as they are only required when a property is sold.
PAS 2035 Retrofit assessments
These are detailed surveys of the home carried out prior to any measures being installed. These lead to recommended measures and detailed information on material choices and installation methods. For government funded schemes like Warm Homes, projects must be PAS 2035 compliant.
PAS compliant Retrofit Assessments need to be carried out by a TrustMark-registered Retrofit Assessor.