The Future Homes Standard is Here: What It Means for Your Water Strategy

On March 24, 2026, the government officially published the final Approved Documents for the Future Homes Standard (FHS). While much of the buzz is around heat pumps and solar panels, there is a major shift happening in how we account for water—specifically hot water. At EasyWaterCalc, we’re helping developers navigate these changes to ensure their projects remain compliant and cost-effective.

From SAP to HEM: A Data Revolution

The transition from the old SAP methodology to the new Home Energy Model (HEM) is a game-changer. Under the new rules, "standard" assumptions are being replaced by high-resolution data.

• Individual Outlet Specs: HEM requires specific data for every single hot water outlet.
• The Energy-Water Link: Because the FHS aims for a 75% reduction in carbon emissions, the energy used to heat water is under the microscope. Reducing water flow isn't just about saving litres anymore; it’s a primary strategy for hitting carbon targets.
• Wastewater Heat Recovery (WWHR): The FHS notional building now assumes the use of WWHR systems. These systems rely on efficient flow rates to function correctly, linking Part G (Water) and Part L (Energy) closer than ever before.

Why You Can’t Leave Part G to the Last Minute

With the FHS standards now published (and coming into force in 2027), the "design stage" has become the most critical part of your timeline. If your water flow rates aren't locked in early, you risk failing your energy performance targets as well as your water limits.

How EasyWaterCalc Helps

Our platform is already updated to reflect the tightening synergy between water and energy. Whether you are aiming for 125L or the stricter 110L per day, we provide the certified proof you need for building control in seconds.

Keep Learning About Sustainable Building 

Navigating the new Future Homes Standard is a journey, and water efficiency is just one piece of the puzzle. If you are looking to dive deeper into how modern systems can reduce your property’s environmental footprint, check out our previous blogs on utilising rainwater for toilet flushing or our deep dive into how soakaways protect your home’s foundation. Staying informed is the best way to ensure your next project is both compliant and future-proof.

Stay ahead in 2026. Generate your compliant Water Efficiency Certificate here.