Quick Turnaround - Our assessor will try to do the HEM EPC in the quickest possible time. This will however depend on the size and complexity of the building.
No Obligation Quote - In order to give you a quote, we will need an electronic copy of the plans and drawings. These can be sent to our email above.
Fully Qualified HEM EPC Assessor -All our assessors are fully compliant with Government regulations and conventions. They all belong to recognized accredition bodies who audit their work.
What we require if you accept our quote - See our "What is required" section below.

What is an HEM EPC?

HEM is short for Home Energy Model which is the UK government's recommended method system for measuring the energy rating of residential dwellings.

This applies to new buildings and those that are being converted or change of use schemes where building regulations apply.

You may also need an HEM for a conversion (i.e. barn conversion/commercial to domestic conversions/conversion of a single dwelling into flats or apartments) or extensions with more than 25% glazing-to-floor area - but slightly different rules apply. If in doubt consult your local building control officer or planning office.

Do I have to have an HEM Assessment?

Yes, an HEM calculation and rating has been a requirement of the Building Regulations Part L since 2025, so all new homes need to have an HEM calculation/rating.

It is recommended that the sooner you can have your HEM assessment carried out the better. HEM calculations must be submitted to building control before works start on site. Think design stage – HEM should be done.

How is HEM used?

HEM has been used as the basis for checking new dwellings for compliance with building regulations in the United Kingdom. A reduced data version of HEM, RDHEM, is used for existing dwellings.In 2025 HEM was cited in Part L of the Building Regulations as a means of assessing dwelling performance.

In order to meet current building regulations, home builders will need to gain a ‘pass’ on their HEM Calculations. Without it, building control will not sign off the development and the property cannot be let or marketed for sale.

A ‘pass’ is gained by meeting several compliance targets around:

1. How well the fabric of the dwelling contains heat

2. Solar gain

3. Quality of construction and commissioning of systems

4. Predicted CO2 emissions from the dwelling

How HEM works

HEM works by assessing how much energy a dwelling will consume, when delivering a defined level of comfort and service provision. The assessment is based on standardised assumptions for occupancy and behaviour. This enables a like-for-like comparison of dwelling performance. Related factors, such as fuel costs and emissions of carbon dioxide (CO2), can be determined from the assessment.

HEM quantifies a dwelling’s performance in terms of: energy use per unit floor area, a fuel-cost-based energy efficiency rating (the HEM Rating) and emissions of CO2 (the Environmental Impact Rating). These indicators of performance are based on estimates of annual energy consumption for the provision of space heating, domestic hot water, lighting and ventilation. Other HEM outputs include estimate of appliance energy use, the potential for overheating in summer and the resultant cooling load.

The HEM rating is based on the energy costs associated with space heating, water heating, ventilation and lighting, less cost savings from energy generation technologies. It is adjusted for floor area so that it is essentially independent of dwelling size for a given built form. The HEM rating is expressed on a scale of 1 to 100, the higher the number the lower the running costs.

What is a HEM Rating?

A HEM Rating is a way of comparing energy performance of different homes – it results in a figure between 1 and 100+ (100 representing zero energy cost and anything over means you are exporting energy). The higher the HEM rating, the lower the fuel costs and the lower the associated emissions of carbon dioxide.

Who will carry out the HEM assessment in?

HEM EPC assessors must be registered with a accreditation body. We can provide you with a fully qualified assessor who is compliant with the latest regulations. An HEM EPC assessor can help the designer or architect to shape the energy profile of a new dwelling – minimising its energy use and carbon emissions.

A HEM Assessor will work from architects plans and construction detail, together with a full HVAC (heating, ventilation and air conditioning) specification. For this reason drawings need to be scaled, accurate and show all elevations, sections, floor and site plans.

What is required?

Site address and postcode.
Site plan to include orientation of the dwelling(s).
Plans of each storey, normally at 1:100 scale.
Elevations drawings - for each elevation.
Sectional drawings of the dwelling.
A written specification which must include:-
Details of the principal heating and hot water system to include make and model of boiler, details of heating emitters, hot water cylinder size (if applicable) and the system controls.
Details of any secondary heating system present.
Details of ventilation systems.
Details of the internal and external lighting.
Details of the construction of all different floors to the property to include type and thicknesses of insulation and any other building products used.
Details of the construction of all different external walls to the property to include type and thicknesses of insulation and other building products used.
Details of the construction of all different roofs to the property to include type and thicknesses of insulation and other building products used.
Details of the doors and windows to include sizes, type of frame, type of glazing, thickness of glazing, any low emissivity applications.
Details of any renewable technologies utilised such as ground source heat pumps, solar water heating or photovoltaics

HEM EPC