Learning by Doing: A Deep Retrofit in Milton
Practical lessons from real-life eco home retrofits in Cambridge.
At Archangel, we believe a great way to learn is to do. Designing buildings for others hones our skills, but working on our own homes takes that learning to another level. It allows us to test ideas, explore new technologies, and experience first-hand the realities of living through the process of change.
Projects like these also help us to empathise more deeply with our clients — to understand the challenges, compromises and small triumphs that come with transforming a home while daily life carries on around it.
This winter, our architect Apostolos will be opening the doors to his own low-energy deep retrofit in Milton as part of Cambridge Carbon Footprint’s Open Eco Homes programme.
It’s a chance for visitors to see how an ordinary 1980s house can be transformed into a warm, efficient and comfortable home — and to learn what it really takes to bring retrofit ideas to life.
Why retrofit matters for Cambridge homes
Across Cambridge, countless homes were built before energy efficiency was a consideration. They are well loved, well located, and full of potential — but often cold, draughty and expensive to heat.
Retrofitting these buildings is one of the most effective ways we can reduce carbon emissions and improve day-to-day comfort. It’s also an act of stewardship: adapting what already exists rather than starting again.
Projects like Apostolos’ home in Milton help us understand what works in practice. They remind us that retrofit is as much about inhabiting wisely as it is about technical performance.
What makes this retrofit different
Apostolos’ home was typical of its time: cavity walls, modest insulation, small windows and an ageing heating system. By designing the retrofit to the EnerPHit standard by Passivhaus, he’s been able to dramatically reduce heat loss and improve comfort while keeping the character and structure of the original house intact.
Upgrades include:
– External wall insulation to improve the building’s thermal envelope
– New high-performance windows and doors
– MVHR (mechanical ventilation with heat recovery) for balanced fresh air
– Air-tightness detailing and careful thermal bridging control
– A focus on measuring and monitoring performance post-completion
While the home didn’t ultimately achieve Passivhaus certification due to airtightness constrains, the process provided valuable insight into how far these principles can be applied in typical UK housing stock — lessons we’re already applying to future client projects.
Learning through doing
For us, design is a form of enquiry. By testing ideas in our own homes, we gain a deeper understanding of how buildings behave, how materials respond, and how people adapt to change.
In Milton, laser scanning was used to capture the existing house in precise detail before work began. This 3D model informed every decision — from junction detailing to insulation thickness — helping to refine both efficiency and craftsmanship.
It’s this process of learning through doing that continues to shape how we approach retrofit for our clients: not as a formula, but as a conversation between building, occupant and environment.
Sharing knowledge through Open Eco Homes
We value the opportunity to share what we’re learning through Cambridge Carbon Footprint’s Open Eco Homes, a wonderful initiative that helps people see sustainable living in practice. It’s a reminder that change happens one conversation, one visit, one idea at a time.
🗓️ Tour dates:
Sunday 26 October — 11am, 1pm & 3pm
Saturday 8 November — 11am, 1pm & 3pm
🎟️ Book your visit here:
https://cambridgecarbonfootprint.org/events/passivhaus-inspired-1990s-home-retrofit-milton/
Designing for a better future
Every project teaches us something — about materials, energy, or the delicate balance between old and new. But most of all, it teaches us about care.
By learning through doing, we become more attentive to the life of buildings and those who inhabit them. That, ultimately, is what drives us: not just to design sustainably, but to design with spirit.
