Zero-Carbon Ready Standards for Non-Domestic Buildings
The Future Buildings Standard (FBS) applies to new non-domestic buildings — offices, warehouses, schools, hospitals, hotels and more. Buildings constructed to this standard will not require retrofitting to become zero carbon once the electricity grid is fully decarbonised.
FBS Notional Building vs Part L 2021
| Element | FBS Standard | Part L 2021 |
|---|---|---|
| Heating (side-lit) | Heat pump | Gas boiler under Part L 2021 |
| Heating (top-lit) | Electric radiant heating | Gas radiant heating under Part L 2021 |
| Solar PV | 40% of foundation area | 20% under Part L 2021 |
| Heat recovery | 80% efficiency | 76% under Part L 2021 |
| Lighting efficacy | 105 lm/W | 95 lm/W under Part L 2021 |
| Airtightness (warehouses) | 3 m³/h/m² at 50Pa | 5 m³/h/m² under Part L 2021 |
Key Changes from Part L 2021
The FBS effectively mandates low-carbon heating in all new non-domestic buildings. Side-lit buildings (offices, schools, hospitals, hotels) use heat pumps, while top-lit buildings (warehouses) use electric radiant heating. Solar PV coverage increases to 40% of foundation area for all building types. Higher-Risk Buildings are exempt from the solar requirement. Lighting efficacy has been set at 105 lm/W — lower than the 150 lm/W originally consulted on, following industry feedback on cost and market readiness.
Impact by Building Type
Capital cost uplift varies by building type: 0.6% for hospitals, 1.1% for warehouses, 1.2% for deep-plan offices, 2.0% for schools, 2.6% for hotels and shallow-plan offices. Offices, hospitals, and schools are expected to see energy bill savings, while warehouses and hotels face higher energy costs — driven by the unit cost of electricity being higher than gas. The overall policy delivers a positive social value of £874m over the appraisal period.
Carbon Savings
The FBS delivers 11.8 MtCO2e of carbon savings over the appraisal period. The vast majority comes from non-traded gas emission reductions. Each tonne of non-traded carbon is saved at a cost of £97/tCO2e — well below the government's Non-Traded Cost Comparator of £171/tCO2e, confirming the policy is cost-effective.
Same Transitional Arrangements
Non-domestic buildings follow the same 24-month transitional arrangement as dwellings: legislation laid March 2026, comes into force 24 March 2027, with a 12-month transition to 24 March 2028. Higher-Risk Buildings have an extended timeline with Gateway 2 applications required by 24 September 2027.