16/10/2025
SAP & SBEM – Demystifying Energy Compliance for Residential and Non-Residential Projects
Written By: enevo
Estimated Time: 5 mins
Building Compliance
Understanding energy compliance in UK construction
Energy compliance is a key tenet of responsible building design. In the UK, every new building, whether a home, school, or office, must demonstrate that it meets strict standards for energy efficiency and carbon emissions under the
Building Regulations.
As the construction industry progresses toward zero-carbon development through the
Future Homes and Future Buildings Standards,
understanding how energy performance is measured has never been more important.
At the centre of this process are two key assessment tools:
SAP (Standard Assessment Procedure)
and
SBEM (Simplified Building Energy Model).
These models not only prove regulatory compliance but also help project teams design buildings that are comfortable, efficient, and ready for the low-carbon future.
What are SAP and SBEM?
Both SAP and SBEM are government-approved methodologies used to measure a building’s predicted energy performance. While they share the same purpose, they apply to different building types.
- SAP focuses on residential buildings, calculating predicted energy consumption, heating demand, and CO₂ emissions. Every new dwelling, whether a detached home or a block of flats, must achieve compliance under Part L of the Building Regulations before completion. The results form the basis of the Energy Performance Certificate (EPC), rated from A to G.
- SBEM, on the other hand, applies to non-residential or commercial properties such as offices, retail units, healthcare buildings, and warehouses. It also results in an EPC but uses a different calculation engine designed to reflect the complexity of commercial services and occupancy patterns.
To learn more about SAP and its role in Part L compliance, visit enevo’s SAP Calculations page.
When are SAP and SBEM calculations required?
Energy assessments are a statutory requirement for most new-builds, extensions, and conversions, all governed by Approved Document Part L of the Building Regulations.
These calculations are typically carried out at two key stages:
- Design stage – to demonstrate compliance before construction begins.
- As-built stage – once construction is complete, confirming that the final specification meets the approved design.
Without compliant SAP or SBEM results, Building Control cannot issue a completion certificate, and an EPC cannot be generated.
The role of SAP and SBEM in design and compliance
Using these tools early in the design phase allows architects and developers to model how design choices will impact performance. Factors such as insulation levels, glazing ratios, ventilation systems, heating sources, and renewable technologies can be tested virtually before any materials are ordered.
This early collaboration prevents costly redesigns later and ensures that the final build meets both Building Regulations and sustainability objectives. Energy modelling also supports planning applications, funding bids, and BREEAM targets, particularly for clients pursuing higher environmental standards.
How SAP and SBEM link to the Future Homes Standard and HEM
The forthcoming Future Homes and Buildings Standards (2026) will require new properties to produce 75–80% less carbon than those built under current rules. Gas boilers will be phased out in favour of heat pumps, solar technologies, and other low-carbon systems.
To support these changes, the current SAP methodology is being phased through SAP 10.3 and will eventually be replaced by the Home Energy Model (HEM) – the next-generation calculation engine designed to provide more accurate, dynamic assessments of energy use and carbon performance in new homes.
Accurate and detailed energy modelling will remain essential under HEM, and by engaging early with accredited assessors, project teams can identify the most cost-effective path to achieving zero-carbon readiness. For a closer look at how the methodology is evolving, see enevo’s insight on SAP 10 and what it means for energy assessment.
Practical steps to achieve compliance
The process typically follows three stages:
- Initial Design Assessment – using accredited software, assessors calculate predicted performance based on drawings and specifications.
- Design Optimisation – recommendations are provided to improve thermal efficiency or reduce emissions, such as adjusting U-values, ventilation rates, or renewables integration.
- As-Built Submission – final data is updated with verified construction details, producing the official EPC and Building Regulations compliance report.
Developers should supply details on insulation, windows, HVAC, lighting, and renewable systems to ensure accurate modelling.
SAP vs SBEM – key differences at a glance
| Feature | SAP | SBEM |
|---|---|---|
| Building Type | Residential | Commercial / Non-residential |
| Output | EPC for dwellings | EPC for non-dwellings |
| Regulation | Part L (Approved Document L) | Part L (Approved Document L) |
| Assessment Stage | Design & As-built | Design & As-built |
Both share the same goal, namely verifying that a building performs efficiently, sustainably, and within regulation.
Why use a specialist energy modelling consultant
Partnering with a specialist ensures the process is handled accurately and efficiently. At enevo’s Building Compliance division, accredited assessors deliver SAP, SBEM, and advanced energy modelling calculations that align with the latest legislation and guidance.
Because enevo’s consultants are already highly experienced in detailed SBEM and thermal modelling, transitioning to the new Home Energy Model (HEM) will be seamless. Our team is already working with the data-driven principles behind HEM, ensuring clients are fully prepared for the upcoming shift in compliance standards.
Our expertise helps project teams identify energy-saving opportunities, avoid compliance delays, and future-proof developments.
Final thoughts
SAP and SBEM are integral tools that guide better design, reduce operational costs, and support the UK’s journey toward net-zero construction. As the Home Energy Model begins to take shape, these principles will remain essential – focusing on accurate data, practical solutions, and resilient design.
Engaging with qualified experts early in the process can simplify compliance, strengthen project outcomes, and ensure every building you deliver meets both current and future expectations.
Get in touch and speak to enevo’s Building Compliance team to arrange SAP, SBEM or future HEM assessments for your next project.
