Passivhaus Compared to the Proposed FHS

Lead author: Rachel Mitchell

This position paper evaluates the Future Homes Standard (FHS) 2025 against Passivhaus Classic, comparing energy performance, heating costs, and carbon emissions. The analysis models two FHS options – one with photovoltaics (FHS PV) and one without (FHS no PV) – against Passivhaus. Findings show that both FHS options result in higher annual energy costs than 2021 regulations, with FHS no PV nearly doubling costs in some cases. In contrast, Passivhaus Classic matches or outperforms FHS PV using only improved building fabric, delivering long-term energy savings without reliance on PV, which is not always feasible and may degrade over time.

To ensure affordability and long-term sustainability in UK housing, the Passivhaus Trust recommends that Future Homes Standard dwellings should cost no more to heat than those built under current building regulations, which will require Passivhaus-level fabric improvements where PV is impractical, and that Passivhaus Classic should be deemed to comply with Approved Document L when the Future Homes Standard is introduced.