Unlocking the potential of existing buildings
Across Oxfordshire, the Cotswolds, the Chilterns, London and throughout the UK, many homes and workplaces were built long before today’s performance expectations. They are often air-leaky, expensive to run, and inconsistent in comfort. At Gresford Architects, we see retrofit as an act of respect — for history, for resources, and for people.
Our director Tom Gresford has personal experience of EnerPhit: he and his partner retrofitted their own family home, The Old Orchard, to EnerPhit standards. This hands-on knowledge ensures our approach combines technical mastery with lived insight.
What is EnerPhit?
EnerPhit is a certification for upgrading existing buildings to be super energy-efficient without demolishing them. Dramatically cutting heating and cooling costs while making it more comfortable and environmentally friendly.
Where phasing is appropriate, we can pursue EnerPhit Step-by-Step certification, supported by an EnerPhit Retrofit Plan (ERP). This allows upgrades to be sequenced sensibly over time without compromising the overall outcome.
Five reasons to use EnerPhit retrofitting:
- Slash your energy bills
Cut your heating and cooling costs to achieve an ultra low energy building by improving the thermal performance of your existing build to meet modern energy efficiency requirements. - Reduce carbon footprint
Buildings account for nearly 40% of global emissions. Prioritise sustainability by retrofitting instead of demolishing, you save the embodied carbon in your existing structure and reduce ongoing energy use. - Comfort all year-round
No more cold drafts or stuffy rooms. EnerPHit buildings maintain consistent temperatures, eliminate condensation and mold, — and provide constant fresh filtered air. - Preserve what matters
Keep the character and heritage of your existing building while bringing it into the 21st century. EnerPHit lets you retain historic facades, character, and architectural charm — no demolition required. - Increase property value
Future-proof your investment. As energy costs rise and building regulations tighten, highly efficient buildings command premium prices. Plus, lower running costs make your property more attractive to buyers and tenants.
A modern wooden house with large windows and a sloped roof, surrounded by a lush garden and trees, under a partly cloudy sky; architecture by Gresford Architects.
The Old Orchard — the deep retrofit of a 1930s detached house, achieving EnerPhit certification with external wall insulation, airtightness strategy, and MVHR — delivering 80% energy savings and exceptional comfort.
An abstract composition with a checkered yellow and green background, large black text reading '3:2 aspect', architecture by Gresford Architects.
Emmington? – A Victorian terrace where period charm meets cutting-edge performance: internal insulation, triple glazing, and smart ventilation raise the home to modern standards without compromise.
Why choose Gresford Architects for EnerPhit?
- Proven expertise: From Oxford townhouses to Cotswold farmhouses, we have delivered EnerPhit-aligned retrofits in diverse contexts.
- Award-winning practice: Winners of the RIBA East Award (2018) for The Deerings Passivhaus, with projects featured by Grand Designs Magazine, Dezeen, The Modern House and The Spaces.
- First-hand knowledge: Tom’s own EnerPhit-level retrofit, The Old Orchard, has been profiled internationally.
- Professional standing: A RIBA Chartered Practice, Green Register accredited, and members of the Passivhaus Trust and AECB.
- Heritage sensitivity: With ties to the Society for the Protection of Ancient Buildings (SPAB), we balance conservation with performance.
- Client-centred ethos: We measure outcomes as well as aesthetics, providing airtightness certificates, MVHR commissioning reports and post-occupancy reviews.
With Gresford Architects, an EnerPhit retrofit is not just an upgrade — it is a transformation into a healthier, more efficient and more resilient home.
