The Future Buildings Standard (FBS) and the Future Homes Standard (FHS) were published together on 24 March 2026, but they cover different building types and use different calculation methodologies. The FBS applies to non-domestic buildings under Part L Volume 2; the FHS applies to domestic buildings under Part L Volume 1 (AD L2 2026; AD L1 2026).
Side-by-side comparison
| Aspect | Future Buildings Standard (FBS) | Future Homes Standard (FHS) |
|---|---|---|
| Building types | Non-domestic: offices, retail, schools, hospitals, warehouses, etc. | Domestic: houses, flats, conversions |
| Approved Document | Part L Volume 2 (2026 edition) | Part L Volume 1 (2026 edition) |
| Calculation methodology | SBEM / National Calculation Methodology (NCM) | Home Energy Model (HEM) |
| Compliance software | iSBEM or approved DSM software | Approved HEM implementations |
| Compliance report | BRUKL (Building Regulations UK Part L) | Dwelling compliance report |
| Solar PV requirement | 40% of foundation area (both zone types, with exemptions) | Required to meet Target Primary Energy Rate |
| Heating requirement | Low-carbon heating in notional building | Low-carbon heating in notional dwelling |
| Enforcement – standard | March 2027 | March 2027 |
| Enforcement – HRBs | September 2027 | September 2027 |
| Transition period | 12 months from enforcement date | 12 months from enforcement date |
| Assessor qualification | NDEA Level 3, 4, or 5 | DEA / SAP assessor |
Key differences explained
Calculation methodology
The most fundamental difference is the calculation methodology. The FBS uses SBEM (Simplified Building Energy Model) or approved Dynamic Simulation Modelling (DSM) software – collectively known as the National Calculation Methodology (NCM). The FHS uses the Home Energy Model (HEM), an entirely new methodology that replaced SAP.
For practitioners, this means the FBS and FHS require different software, different qualifications, and different assessment approaches. You cannot use HEM for a non-domestic building or SBEM for a dwelling.
Solar PV approach
The FBS takes a prescriptive approach to solar PV, requiring 40% of foundation area for both side-lit and top-lit buildings (consultation response, para 3.11, p18). The current NCM 2021 Equation 9 still uses a weighted formula (20% side-lit / 40% top-lit) - this will be updated when the 2026 NCM is published. The FHS takes a performance-based approach where PV is effectively required to meet the target metrics but without a specific area rule. See our solar PV requirements page for full details on the non-domestic approach.
What they share
Despite the differences, both standards share the same enforcement dates, the same transition period structure, and the same policy goal: ensuring new buildings are highly energy-efficient and ready for a decarbonised electricity grid. Both were developed through the same consultation process and published in the same Building Circular (01/2026).
For domestic guidance
This site focuses on the non-domestic Future Buildings Standard. For comprehensive guidance on the Future Homes Standard and HEM for domestic buildings, visit our sister site, the HEM Guide.
Frequently Asked Questions
What is the difference between FBS and FHS?
The Future Buildings Standard (FBS) covers non-domestic buildings and uses SBEM for compliance. The Future Homes Standard (FHS) covers domestic buildings and uses the Home Energy Model. Both were published on 24 March 2026 and are enforced from 2027.
How do I know which standard applies to my building?
If your building is non-domestic (offices, retail, schools, hospitals, warehouses, etc.), the Future Buildings Standard applies. If it is a dwelling (house, flat, or conversion), the Future Homes Standard applies. Mixed-use buildings may need to comply with both.