Home Energy
Model
The successor to SAP — we’re ready.
The Home Energy Model (HEM) is the government’s new methodology for assessing the energy performance of new homes — designed for the Future Homes Standard and a low-carbon grid. UK Building Compliance is ready to help your projects prepare.
- 15+ years of new-build energy assessment experience
- Practical design advice, not just a pass/fail number
- Full compliance package — energy, airtightness & ventilation
15+
Years Experience
New-build
Specialists
On Request
Fixed Pricing
UK-wide
Coverage
What is the Home Energy Model?
The Home Energy Model is the government’s new energy-assessment methodology for new dwellings — the successor to SAP, underpinning the Future Homes Standard. It is built around a low-carbon world: heat pumps, solar PV, smart controls and a decarbonising electricity grid.
Unlike SAP, which uses simplified annual averages, HEM uses more detailed modelling to produce a more accurate picture of a home’s real-world energy performance. That detail matters as buildings become better insulated and more electrified — the older methodology was not designed for the technologies now being specified.
Why does it matter for my project?
The Future Homes Standard is being introduced as part of a fundamental update to Part L for new dwellings. Understanding how HEM models your design early — fabric performance, heating strategy, renewables — means you can make the right specification decisions now rather than redesigning under pressure later.
HEM and the transition from SAP
During the transition period, SAP calculations remain in use for many projects. We will confirm which methodology applies to your project and timeline, and guide you through any transition requirements as they become clearer.
Built for low-carbon new homes.
HEM models the technologies that will define new housing over the coming decade. Here is what the methodology is designed to assess.
Heat Pumps & Low-Carbon Heating
HEM is specifically designed to model air source and ground source heat pumps accurately — a step change from SAP, which was calibrated around gas boilers. It reflects the real efficiency of heat pump systems in well-insulated homes.
- Air source & ground source heat pumps
- Accurate performance at low flow temperatures
Solar PV & Smart Controls
HEM incorporates solar PV generation, battery storage and smart controls within a framework that reflects a decarbonising electricity grid — so the carbon benefit of on-site generation is modelled more realistically than in SAP.
- Solar PV generation modelled accurately
- Grid carbon intensity factored in
Fabric Performance
The model assesses U-values, thermal bridging, airtightness and ventilation strategy in detail. Fabric-first design still matters under HEM — a well-insulated, airtight envelope reduces the load on any heating system.
- U-values, thermal bridging & airtightness
- Ventilation strategy modelled
Compliance Documentation
Assessment outputs are structured to support your building control submission. We produce clear documentation alongside design guidance so your team knows exactly what the model is telling you.
- Building control submission ready
- Design guidance included
Real advice, not just a number.
15+ years of new-build energy assessment experience, practical design guidance, and a full compliance package from one provider — energy modelling, airtightness and ventilation testing all under one roof.
Design guidance included
Every assessment includes actionable design advice — if the model shows a compliance gap, we tell you the cost-effective routes to close it before it becomes a problem on site.
15+ Years of New-Build Experience
Our assessors have been delivering Part L energy assessments — SAP, SBEM and energy statements — for over 15 years. That depth of experience carries directly into HEM work.
Practical Design Advice
We provide actionable design guidance, not just a pass/fail number. If the modelling shows a compliance gap, we identify cost-effective routes to close it before it becomes a problem on site.
Forward-Looking Methodology
HEM is built around heat pumps, solar PV, smart controls and a decarbonising grid. We help you understand what that means for your specific design and specification choices.
Transition Guidance Included
The shift from SAP to HEM is ongoing. We track the regulatory position and explain clearly which methodology applies to your project and when the requirements are likely to change.
Compliance Documentation
HEM assessment outputs are prepared to support your building control submission — clear, well-structured and backed by our assessment team if questions arise from your inspector.
One Provider, Nationwide
Energy modelling, air pressure testing, ventilation testing and more — from a single provider covering all UK regions. One point of contact, one invoice, no coordination gaps.
Three steps from plans to compliance.
From design review to compliance documentation. Straightforward, with practical guidance at every stage.
Design Review
We take your plans, fabric specification and proposed building services. We confirm what we need from you and turn around an assessment programme promptly.
HEM Assessment
We model the dwelling under the Home Energy Model methodology, flag where the design needs to improve, and identify cost-effective routes to compliance before you commit to a specification.
Documentation & Guidance
You receive compliance documentation suitable for your building control submission, alongside clear design guidance your team can act on. We remain available for questions as the project develops.
Fixed prices, on request.
Tell us about your project — the number of dwellings, design stage and timeline — and we will come back with a fixed price that covers the assessment and guidance documentation.
Fixed price quoted per project, based on number of dwellings, complexity and design stage. Contact us with your project details for a prompt quote.
- Full HEM modelling of the dwelling
- Design guidance & compliance recommendations
- Building control submission documentation
- Nationwide coverage
Prices vary with project size, number of dwellings and complexity. Contact us for an accurate quote for your project.
Prepare your projects for the Future Homes Standard
Talk to us about your new-build programme. We’ll explain where HEM applies to your timeline and what you need to do now.
HEM questions.
Common questions about the Home Energy Model — what it is, how it differs from SAP, and how the transition works in practice.
Still Got a Question? Ask Us What is the Home Energy Model?
The Home Energy Model (HEM) is the government's new energy-assessment methodology for new homes — the successor to SAP under the Future Homes Standard. It is designed around low-carbon technologies, using more detailed modelling than the current SAP methodology to give a more accurate picture of a home's energy performance.
Is HEM mandatory yet?
The Future Homes Standard and its accompanying Home Energy Model are being introduced as part of a wider update to building regulations. The transition from SAP is ongoing and the exact timing is subject to government consultation. We keep close track of the regulatory position and will advise on which methodology applies to your specific project.
How is HEM different from SAP?
HEM is a more detailed model built around low-carbon technologies — heat pumps, solar PV, smart controls and a decarbonising electricity grid. It uses finer-grained calculation intervals and is designed to reflect real-world performance more accurately than the older SAP methodology.
Do I still need a SAP calculation while HEM is being introduced?
During the transition period, SAP remains in use for many projects. We will confirm which methodology applies to your project once we understand the design stage and submission timeline. Our SAP calculation service remains fully operational.
Who needs a Home Energy Model assessment?
House builders, developers, architects and self-builders planning new dwellings who want to understand and prepare for the Future Homes Standard requirements. Early modelling helps identify compliance risks before they become expensive design changes.
What does a HEM assessment involve?
We review your plans, fabric specification and proposed building services, then model the dwelling under the Home Energy Model methodology. We flag where the design needs to improve to achieve compliance and suggest cost-effective routes forward. You receive documentation suitable to support your building control submission.
Can UKBC handle the full compliance package?
Yes. We offer energy modelling alongside air pressure testing, ventilation testing, overheating assessments and more — all from one provider. This avoids coordination gaps between separate suppliers and keeps your compliance programme on track.
How much does a HEM assessment cost?
Fees are provided on request and vary with project size and complexity. Contact us or use the quote form with your project details and we will come back to you promptly.