Designing low-energy homes for Oxfordshire, the Cotswolds and beyond.
PassivHaus design represents the most rigorous standard for energy-efficient building in the world. Across Oxfordshire, the Cotswolds, the Chilterns, London and throughout the UK, PassivHaus homes deliver ultra-low energy use, exceptional comfort, and unrivalled air quality.
At Gresford Architects, we are experienced PassivHaus architects with a reputation for combining advanced building science with elegant, site-specific design. PassivHaus is not simply a certificate for us — it is a philosophy: a way of creating homes that are warm in winter, cool in summer, and profoundly sustainable, without compromising beauty or context.
What is PassivHaus?
Originating in Germany in the early 1990s and now internationally recognised, PassivHaus is a voluntary building standard that ensures homes meet the strictest criteria for comfort and efficiency.
Core performance targets include:
- Space heating demand ≤ 15 kWh/m²·yr
- Primary energy demand ≤ 120 kWh/m²·yr
- Airtightness n₅₀ ≤ 0.6 h⁻¹ @50Pa, confirmed by blower-door testing
- Thermal bridge free detailing (Ψ-values minimised)
- MVHR (mechanical ventilation with heat recovery) delivering fresh, filtered air year-round
PassivHaus comes in three levels — Classic, Plus and Premium — depending on renewable generation and energy balance. The result: homes that use up to 90% less energy for heating and cooling than conventional construction.
At the heart of PassivHaus is a fabric-first approach, verified through PHPP (Passivhaus Planning Package) modelling, ensuring buildings perform in reality, not just on paper.
Our approach to PassivHaus projects
Every PassivHaus begins with a rigorous understanding of site, climate and client aspirations.
Our six-step PassivHaus process:
Feasibility → PHPP energy modelling → Detail design → Site QA & airtightness testing → MVHR commissioning → Post-occupancy evaluation (POE).
Our director Tom Gresford brings both professional and personal experience. He has delivered award-winning low-energy projects including The Deerings, which won a RIBA East Award (2018) for its PassivHaus performance, and his own family home, The Old Orchard, retrofitted to EnerPhit standards. Both projects have been widely published in Grand Designs Magazine, Dezeen, The Modern House and The Spaces.
Modern two-storey house with a flat roof, timber cladding exterior, large windows, and a driveway with an electric car, architecture by Gresford Architects.
The Deerings – a new-build family home where triple glazing, timber structure, and MVHR combine to create a sanctuary of comfort with negligible running costs.
A modern, multi-level house with a pool, surrounded by trees and landscaped pathways, designed by Gresford Architects in a lush green setting.
Hartford Greys – The deep retrofit of a Victorian townhouse, preserving historic character while achieving PassivHaus standards for energy, comfort and air quality.
A rural landscape with a modern grey house, trees, and a clear sky, viewed across an open field with some plants in the foreground. Architecture by Gresford Architects.
Chieveley – a rural PassivHaus Plus, generating more energy than it consumes through a marriage of solar technology and ultra-high performance fabric.
Why choose Gresford Architects for PassivHaus design?
- Certified expertise: We are certified PassivHaus designers and long-standing members of the Passivhaus Trust.
- Award-winning track record: Winners of the RIBA East Award for The Deerings and shortlisted for other RIBA Awards, with projects profiled in leading design media.
- First-hand knowledge: Tom Gresford has lived in an EnerPhit-certified home, bringing real-world insight to every client project.
- Professional standing: A RIBA Chartered Practice, Green Register accredited, and members of the AECB (Association for Environment Conscious Building).
- Heritage sensitivity: With links to the Society for the Protection of Ancient Buildings (SPAB), we understand how to balance PassivHaus rigour with conservation.
- Client-focused delivery: From feasibility to final blower-door test, we guide clients through every decision, providing clarity and confidence.
Our goal is simple: PassivHaus homes that are tailored, timeless, and transformative.
Ready to live the PassivHaus difference?
If you want a home that is warm, quiet, and supremely efficient — built to perform for generations — let’s talk.
