EnerPHit: The Retrofit Standard That Changes Everything
You’ve got a beautiful home. Or at least, the bones of one.
Maybe it’s draughty in winter, hot in summer, or expensive to run.
You want to upgrade it — not just to look better, but to work better.
That’s where EnerPHit comes in.
It’s the Passivhaus standard for retrofitting existing homes.
Designed for people who care about comfort, energy use, and doing things properly.
It’s not a quick fix. It’s a deep, thoughtful upgrade. And it works.
Little Venice Townhouse - EnerPHit retrofit
Why clients come to us for EnerPHit
If you’re here, you’re probably already thinking long term.
You want a home that feels good in every season, with low energy bills and fresh, healthy air.
But you don’t want to lose what makes your home special — its character, its materials, its history.
We help you do both.
Our approach is calm, careful, and complete.
We assess your home as a whole: its performance, layout, fabric and flow.
We’ll show you what’s possible — and what’s worth doing — to get you as close to EnerPHit performance as makes sense.
And we design it beautifully.
What’s involved?
EnerPHit means reducing heat loss and improving airtightness.
It means triple glazing, proper ventilation, and insulation that doesn’t suffocate your walls.
It means natural materials that let your building breathe — not trap moisture inside it.
But it also means clarity.
We model everything before we draw anything.
We use PHPP, the Passivhaus Planning Package, to test what works best for your home, your budget and your build.
The result is a clear strategy — whether you go all in, or plan it in stages.
And a home that feels the way you always hoped it would.
Will it suit your home?
Yes — especially if it’s a Victorian or Edwardian terrace, a 1930s semi, or a townhouse in a London conservation area.
These homes were solidly built but poorly insulated. We can change that — without losing their charm.
You don’t have to rip everything out.
You don’t have to cover up every original feature.
You just need a smart plan, sound design, and a team that knows how to make it work.
Which is Right for Your Project?
| AECB Standard | EnerPHit (Retrofit) | Passivhaus (New Build) | |
|---|---|---|---|
| Space Heating Demand | ≤ 40 kWh/m²/yr | ≤ 25 kWh/m²/yr | ≤ 15 kWh/m²/yr |
| Airtightness | ≤ 1.5 ach@50Pa | ≤ 1.0 ach@50Pa | ≤ 0.6 ach@50Pa |
| Primary Energy Demand | ≤ 120 kWh/m²/yr | ≤ 120 kWh/m²/yr | ≤ 120 kWh/m²/yr |
| Certification | Optional | Required | Required |
| Best For | Upgrades to existing homes, phased retrofits | Deep retrofit of existing homes | High-performance new builds |
Read more about AECB or Passivhaus design
What we offer
We offer a Retrofit Strategy Service — your roadmap to a better home.
It includes:
A site visit and energy assessment
PHPP modelling to explore the options
Design guidance for light, deep or staged retrofits
Clear technical recommendations that match your home and your goals
We also offer technical design and support throughout the project.
So whether you're working with a builder, contractor or another architect, we’ll help you get it right.
This isn’t just about numbers
Yes, you’ll use less energy.
Yes, your bills will drop.
Yes, your carbon footprint will shrink.
But more importantly, your home will feel better.
The temperature will be steady. The air will be fresh. The rooms will be quieter.
You’ll want to sit by the windows in winter.
You’ll notice how calm it feels, how the light moves, how easy it is to live in.
That’s the real goal. And it’s absolutely possible.
Let’s Talk
We’ve helped London homeowners make smart, confident retrofit decisions — from light-touch upgrades to full EnerPHit overhauls.
We’d love to help you do the same.
Book a call to talk through your project.
No pressure. Just useful, honest advice from a team who cares about homes that work — and last.