The Future Homes Standard (FHS) is now published. If you're developing in London, here's what changes at feasibility stage.

The Future Homes Standard (FHS) has now been formally published. For developers and design teams working on residential projects in London, the implications are immediate and far-reaching — particularly at feasibility stage, where the decisions that will define a project's performance are made.

This piece sets out what has changed, what it means in practice, and where the key decision points now sit for teams working to programme and budget.

What the FHS Requires

The Future Homes Standard mandates a significant uplift in energy performance for new residential development. New homes must produce 75–80% fewer carbon emissions than those built to the previous standards under Part L. In practice, this means gas boilers are effectively off the table for new-build residential, and fabric performance requirements are materially higher.

The headline changes are:

Energy: New homes must be highly energy efficient and use low-carbon heating. Heat pumps — air source or ground source — are the primary compliant solution for most schemes. District heating connected to a low-carbon source is also viable where available.

Fabric: U-values for walls, roofs, and floors are more stringent. The trade-off between fabric performance and mechanical systems that existed under previous standards is narrowed. Better fabric means smaller, cheaper mechanical plant — this relationship is now more linear and more important to understand at feasibility.

Ventilation: Mechanical ventilation with heat recovery (MVHR) is increasingly the default for high-performance residential. This has spatial and cost implications that need to be priced and planned from the outset.

"The decisions that will define a project's performance are made at feasibility — not later."

What Changes at Feasibility

The FHS raises the stakes for early-stage decision-making in several concrete ways.

Plant space: Heat pump plant — particularly ground source arrays or larger air source arrays for multi-unit schemes — requires space that must be identified and allocated early. Retrofitting plant room locations into an already-fixed plan is expensive and often impossible without compromising net area.

Structural strategy: Higher fabric performance requirements mean thicker wall build-ups in some construction systems. This has implications for structural grid, façade detailing, and GIA calculations. These need to be understood before the scheme is fixed.

Cost planning: The cost premium for FHS-compliant construction is real but manageable when planned for. When it arrives as a surprise in detailed design, it creates pressure that tends to produce worse outcomes. Early cost modelling that reflects the actual specification is essential.

Planning interface: Many London boroughs have energy policies that sit above national standards. Understanding the local authority's position on FHS, renewable energy requirements, and urban greening early avoids abortive work later.

Our Recommendation

For any residential scheme at early stage in London, the energy and sustainability strategy should now be a first-order feasibility item — not a downstream appointment. The decisions being made about structural system, floor-to-ceiling heights, plant allocation, and façade strategy are all directly connected to FHS compliance. Making them without that context is a risk that is straightforward to avoid.

If you are working on a residential scheme in London and would like to understand the FHS implications for your project, we are happy to talk through the specifics.