Eco-Home: How Much Will it Cost?
We help Maximise Your Rental Income with Eco-homes and Luxury Holiday Homes, provided by RIBA Chartered Architects.
An example of an eco-home we designed in Birmingham, applying principles from the Pretty Good House approach. The home is oriented for optimal south-facing sunlight and features high levels of insulation, exceeding building regulations to deliver genuine eco performance.
Introduction - Eco-Home: How Much Will it Cost?
Eco-homes can offer significant long-term savings. Features like solar panels often pay for themselves over time through lower utility bills. But how much does it actually cost to build an eco-home, and is the initial investment out of reach for the average self-builder?
In this article, we break down the real costs of building an eco-home. More importantly, we offer a practical and cost-effective approach that delivers most of the benefits of a green home without the extreme premium price tag.
The Financial Breakdown: What an Eco-Home will cost
Let’s break down some hypothetical numbers for building a modest eco-home:
Standard construction: ~£150,000 build cost.
Passive House standard: ~£450,000.
“Pretty Good House” approach: roughly £180,000–£200,000.
As you can see, a “Pretty Good House” has a higher upfront cost than a basic new-build, but it’s far lower than a full Passive House. And the long-term savings on energy bills, maintenance, and even resale value can more than justify that extra initial investment.
Homeowners and developers who take this middle path often see energy savings of 30–50% compared to standard homes. Over 30 years, that could translate into tens of thousands of pounds saved on utilities. Furthermore, the reduced environmental impact—lower carbon emissions and less reliance on fossil fuels—is a huge bonus that’s hard to quantify but equally important. One ongoing project of ours, Renewable Container Living, is a great example of the “Pretty Good House” approach in action, delivering major efficiency gains without a massive budget increase.
Eco-home construction drawing: Section detail illustrating the build-up for an elevated eco-cabin. The design features ground screw foundations supporting a steel structure, with rigid insulation in a double layer beneath the floor. The wall assembly features OSB/plywood sheathing with sealed joints, a fully adhered membrane for airtightness, and a combination of multi-foil and hybrid insulation for enhanced thermal performance. External siding is fixed over the insulation layers, and an end board completes the floor perimeter.
Passive House vs. Pretty Good House: Finding the Balance
While solar panels offer a clear return on investment, what about other aspects of sustainable construction? Take the Passive House standard, for example, a design concept that promises near-total energy efficiency. Yet achieving this level of performance often comes at a cost three to four times higher than conventional construction. For those with the means, a Passive House can be an incredible investment, but for many eco-home builders, it’s simply out of reach.
This is where a more balanced approach comes into play. In the book Pretty Good House, author Dan Kolbert argues for homes that are excellent in energy efficiency but don’t exceed reasonable environmental or financial payback thresholds. The idea is simple: instead of pursuing perfection at any cost, aim for a home that’s “pretty good.” In practice, that means a house that significantly reduces energy consumption and environmental impact, without breaking the bank or chasing diminishing returns.
A section detail of an eco-home floor build-up shows all the layers of a high-performance design. It goes from the internal plasterboard and vapour barrier, through mineral wool insulation, a service void and air gap, and spray foam insulation, down to the structural shipping container base and an external larch cladding.
Build an Eco-Home that lasts
I often talk about this, and I believe it’s an issue being ignored in the UK market. Building with natural, high-quality materials may cost more up front, but over the long term, it’s actually cheaper. This is sometimes called “boot economics”: the idea that a well-made item lasts much longer, even if it costs more at the start, than a cheaper alternative (like investing in one good pair of boots versus replacing many flimsy pairs).
In the same way, it’s worth investing in construction systems and materials that will make your eco-home durable. A well-built home using quality natural materials will last for many decades, requiring fewer repairs and replacements. Over its lifespan, it provides far greater value, both financially and in quality of living, than a poorly built house that might need major work in just a handful of years. You can read more about this in our article Choosing Long‑Lasting, Eco‑Friendly Materials.
Renewable Energy Systems in Your Eco-Home
Energy costs in the UK are among the highest in the world—several times higher than those in the US. But there’s more to an eco-home than just trimming your utility bills. Pairing a “Pretty Good House” design with renewable energy generation and battery storage can actually make your home energy-positive (producing more energy than it uses).
For example, a well-insulated eco-home with a 7.68 kW solar PV array and a 10 kW battery system can generate around 6 MWh of electricity per year—more than the ~4.8 MWh the home typically consumes. This means you could sell surplus energy back to the grid, effectively getting paid for your home’s efficiency.
Meanwhile, solar technology has become far more affordable—around 90% cheaper than it was a decade ago. Providers like Octopus Energy will even pay you for any excess electricity you export. In short, your home’s sustainability can turn into a source of income, not just savings.
In one of our recent projects, we designed and self-built an eco-home with an organic, curved timber structure set on raised foundations. This custom home is extremely well-insulated and uniquely crafted, which typically costs between £2,000 and £3,000 per square metre to build (so a 100 m² house might be £200,000–£300,000). However, by applying “Pretty Good House” principles in the design, we cut the client’s home energy operating costs by about 77%. Smart, efficient design can dramatically reduce running costs even for a high-end, bespoke eco-home.
Conclusion: A Common-Sense Approach to Eco-Home builds
Building sustainably doesn’t have to be an all-or-nothing proposition. By choosing a well-considered “Pretty Good House” approach and incorporating renewable energy systems, eco-home builders can enjoy the best of both worlds: significant long-term savings and a more sustainable lifestyle. At the same time, you’ll be future-proofing your investment against rising energy costs and environmental uncertainties.
If you’re considering an eco-home and are not sure how much it will cost, let’s talk. Feel free to get in touch or book a free 20-minute project planning consultation by clicking the link below. We are a RIBA Chartered architecture firm based in Birmingham, but we work across the country for the right project.
