Passivhaus plays a pivotal role in the future of sustainable architecture. Buildings are a significant culprit of carbon emissions - The operations of buildings account for 30% of global final energy consumption and 26% of global energy-related emissions.

Passivhaus is a tested solution to deliver net-zero-ready new and existing buildings optimised for a decarbonised grid and improving occupant health and wellbeing. ErerPHit is the retrofit standard. There are several benefits, and many are interconnected - low energy bills, constant fresh air, superior internal comfort, peaceful and quiet interiors are just a few of them.

Interior design plays a critical role in whole project success. Space planning and furniture layouts have a significant impact on building services and lighting positions, which are critical to fix at early stages as it is more difficult to move services as projects progress with Passivhaus. Appointing us early and as part of the full design team ensures that projects are efficiently and robustly coordinated, playing to each consultant’s strengths.

We have collaborated on several projects achieving Passivhaus or EnerPHit certification - most notably on the Entopia Building for the Cambridge Institute for Sustainability Leadership - which aims to be an exemplar of the EnerPHit standard for future projects. PHT Patron Architype led the team alongside PHT Member BDP and Max Fordham.

The Entopia Building, formerly 1 Regent Street, is a five-storey concrete frame structure with a basement originally constructed in 1939. The refurbishment and retrofit ran from 2021-2022 and cost £12.67 million. Achievements include:

• 35% cut in heat loss
• 15% energy requirements of original building
• 62,332kg CO2e avoided in construction materials
• 60% of the furniture, lighting and PV canopy was second-hand thus saving 21,000 kg of carbon