Future Homes Standard confirmed: focus now turns to practical implementation

Paul Kennington, Technical Director at VEKA plc, explains why clarity on calculation methodology will be critical to ensuring the Future Homes Standard works in practice

The confirmation that the Future Homes Standard (FHS) will come into force in March 2027 provides welcome clarity for the housebuilding sector. After several years of consultation and industry engagement, the direction of travel is now firmly established, allowing the focus to move from expectation to practical preparation.

In many respects, the headline performance targets for dwellings remain consistent with earlier proposals. Notional U‑values for windows will remain at 1.2 W/m²K, with doors typically at 1.0–1.2 W/m²K depending on construction type. This reflects the progress already made across the fenestration sector and will feel familiar to many designers, fabricators and installers.

However, the most significant change introduced by the Future Homes Standard is not the targets themselves, but how performance is calculated and evidenced in practice.

Moving closer to real‑world performance
Under the new approach, U‑values for windows and doors in new dwellings must be based on the actual size and configuration of the products installed, rather than standard reference dimensions. This includes non‑structural elements such as frame sections, sills, add‑ons or frame extensions, couplers and decorative glazing bars, all of which can influence overall thermal performance.

Performance will now be assessed using average area‑weighted calculations, meaning the longstanding ‘standard window’ approach will no longer be acceptable for new dwellings. This shift is intended to ensure that calculated values more accurately reflect what is installed on site and how products contribute to the building’s overall energy performance.

For specifiers, fabricators and installers, understanding how configuration choices affect calculated performance will be a key part of preparing for implementation.

Clarity and consistency across the supply chain
A similar direction is also emerging in Wales. The Welsh Government has confirmed changes to Part L of Welsh Building Regulations, due to come into force from March 2027, with a greater emphasis on real‑world building performance and updated calculation methodologies for new homes. This growing alignment across the UK reinforces the importance of consistent, evidence based approaches to demonstrating product performance throughout the supply chain.

As with any regulatory change, clear interpretation will be essential. Terminology and component descriptions can vary across the supply chain, creating the potential for inconsistent application if not properly aligned.

The intent of the Future Homes Standard is not to introduce unnecessary complexity, but to improve transparency and consistency. Many of the technical capabilities required to support this more detailed approach already exist within the industry.

Supporting compliance through robust data

While the Future Homes Standard does not dramatically alter thermal thresholds, it does increase the importance of reliable technical data and calculation tools.

At VEKA, we have been preparing for this direction of travel for some time. Our WinDoPlan software already supports average area weighted calculations using actual sizes and configurations, helping our partners understand how ancillary components may influence thermal performance at an early stage.

With implementation approaching, specification decisions are already being made that could affect future compliance. Early understanding of the calculation methodology can help reduce the risk of late stage design changes and support a smoother transition.

The Future Homes Standard represents a continuation of the industry’s progress towards improved building performance.

The priority now is ensuring the supply chain has the clarity, confidence and technical support needed to implement the standard effectively in practice.