Belfasts First Passive House Bungalow and What It Cost to Build

# Belfast’s First Passive House Bungalow and What It Cost to Build

I’ve been following the passive house movement for years, watching it slowly creep across Europe and wondering when it would properly land in Northern Ireland. The honest truth is, I’d almost given up hope. Then John Carrigan went and built 219 of the things in Belfast, and suddenly we’re not just talking about it anymore – we’re actually living in them.

When rising fuel bills got Carrigan interested in Passivhaus (Climate NI), he didn’t just dip a toe in the water. The man’s a senior executive at Fraser Millar Estates (Everyday Climate Hero), so when he decides to do something, it happens at scale. The result is Lancaster Park, Northern Ireland’s second large scale residential Passivhaus certified development on Comber Road (Sustainable NI), and what’s being called the largest certified Passivhaus residential project in the UK and Ireland (BusinessFirst).

What I want to tell you about is what this actually means for regular people thinking about building or buying a genuinely sustainable home, and more importantly, what it costs.

| **Development** | **Lancaster Park, Belfast** |
|—|—|
| **Developer** | Fraser Millar Estates |
| **Homes Built** | 219 to Passivhaus standard |
| **Annual Heating Cost** | £450 (estimated) |
| **Development Value** | £70 million |

## The Background You Need to Know

Passivhaus isn’t new – it’s been kicking around Germany since the 1990s – but it’s taken this long to get proper traction here. The principle is dead simple: build a house so well insulated and airtight that it barely needs heating. We’re talking about homes that use roughly 90% less energy for heating than a typical UK house.

What makes Lancaster Park significant isn’t just that someone finally built passive houses in Belfast. It’s that Carrigan proved you can do it at scale and make it financially work. This is a £70 million flagship development (BusinessFirst) that aims for PHI LEB certification and will be the largest privately funded scheme certified to PHI LEB in the UK and Ireland (Passivhaus Trust).

The timing matters too. When Carrigan got interested in this, we were heading into an energy crisis that’s made heating bills genuinely frightening for most people. A £30 million Passivhaus development (Insider Media) suddenly doesn’t look like an expensive experiment – it looks like the sensible thing to do.

The recognition followed. Carrigan was recognised as an Everyday Climate Hero at COP26 (Belfast Telegraph), which is all well and good, but what I care about is whether this actually works for people who have to live in these houses and pay the bills.

## What Makes These Houses Actually Special

Look, I’ve seen enough green building projects that look impressive on paper but fall apart in practice. The thing about Passivhaus is that it’s not about trendy materials or complicated technology. It’s about doing the basics so well that the house barely needs active heating or cooling.

The standard is brutally specific. Your house can’t use more than 15kWh per square metre per year for heating. For context, a typical UK house uses about 150kWh per square metre. That’s not a small improvement – that’s a complete rethink of how buildings work.

What this means in practice is extraordinary attention to thermal bridging, airtightness, and insulation levels that would have been considered insane ten years ago. We’re talking about wall assemblies that might be 400mm thick, triple-glazed windows as standard, and mechanical ventilation with heat recovery systems that capture the warmth from stale air being extracted.

At Lancaster Park, they’re targeting what’s described as the gold standard of low energy housing (RTÉ). But here’s what that actually means for someone living there: the estimated heating cost for the show house is £450 per year (RTÉ).

Think about that for a minute. £450 a year. Most people I know are looking at heating bills three or four times that, and that’s before we factor in where energy prices are heading.

But the energy savings aren’t the only benefit. Improved indoor air quality is a key advantage of Passivhaus buildings (Sustainable NI). The mechanical ventilation systems mean you get fresh, filtered air constantly, without the draughts and cold spots that come with opening windows in winter.

I’ve spent time in passive houses, and there’s something genuinely different about how they feel. The temperature is consistent throughout – no cold bedrooms or overheated living rooms. The air feels fresh without being stuffy. In winter, you can walk around in a t-shirt. In summer, they stay cool without air conditioning.

## The Honest Assessment of What This Costs

Right, let’s talk money, because this is where most people get nervous about passive house construction.

I can’t give you exact build costs for Lancaster Park – developers don’t usually publish those figures – but I can tell you what the broader market looks like and what this development suggests about costs.

The conventional wisdom has been that passive house construction adds 10-15% to build costs. In practice, what I’ve seen is more complex than that. Yes, your materials costs go up – better windows, more insulation, mechanical ventilation systems. But you also save money by not needing a traditional heating system. No boiler, no radiators, no gas supply.

Where costs really add up is in the design and construction process. Getting to passive house standard requires much more precise design, better quality control during construction, and testing to verify performance. You can’t just wing it like you might with a standard build.

The £70 million development cost for 219 homes works out to roughly £320,000 per unit, but that includes land costs, infrastructure, profit margins, and finishing to a high standard. It’s not a direct comparison to self-build costs, but it suggests that passive house construction at scale isn’t prohibitively expensive.

What’s encouraging is that this shows developers can thrive with Passivhaus (Passive House Plus). If the numbers didn’t work, Fraser Millar wouldn’t have built 219 of them.

For someone thinking about self-building, I’d budget for 15-20% higher construction costs compared to Building Regulations minimum. But remember, you’re front-loading costs that you’ll save on energy bills for decades. At current energy prices, that payback period is looking very attractive.

The maintenance costs are actually lower than a conventional house. No boiler to service annually. No heating system to repair. The mechanical ventilation needs filter changes twice a year and that’s about it.

## What Doesn’t Work As Well As You’d Hope

I need to be honest about the limitations, because passive house isn’t perfect for everyone.

First, the design constraints are real. Getting to passive house standard limits your architectural options. Big areas of glazing facing north? Forget it. Complex building shapes with lots of thermal bridging? Not happening. If you’re dreaming of a Victorian-style extension with bay windows and complex roof lines, passive house probably isn’t for you.

The mechanical ventilation takes getting used to. Most people love it once they’re accustomed to it, but initially it feels weird having your house breathe for you. Some people find the gentle hum annoying, though modern systems are much quieter than earlier generations.

Overheating can be an issue in summer, particularly in south-facing rooms with large windows. The houses are designed to stay cool, but we’re seeing more extreme summer temperatures than the standard originally accounted for.

There’s also the reality that achieving true passive house performance requires occupants to understand how the house works. Leave all your windows open in winter and complain that your heating bills are high? That’s on you, not the house. Use the trickle vents incorrectly and wonder why you’re getting condensation? Same thing.

The building industry here is still learning. Not every contractor understands the precision required for passive house construction. Horror stories exist of expensive builds that fail certification because someone didn’t pay enough attention to airtightness details.

## The Legacy This Is Creating

What Carrigan has done at Lancaster Park matters beyond Belfast. He’s proven that passive house construction can work commercially in the Northern Ireland market, in our climate, with our building industry.

The certification they’re targeting – PHI LEB – is significant because it shows they’re not cutting corners or going for a watered-down standard. This is proper passive house construction that will be independently verified.

More importantly, 219 families are going to live in these houses. They’re going to experience what it’s like to have heating bills under £500 a year. They’re going to tell their friends and family. Word spreads.

The development is also training up local contractors, suppliers, and trades in passive house construction techniques. That knowledge stays in the market and makes the next passive house project easier and cheaper.

I’m already seeing other developers taking notice. When energy costs were cheap, passive house looked like an expensive luxury. Now it looks like sensible insurance against future price volatility.

## The Verdict

Lancaster Park isn’t perfect – no development ever is – but it’s exactly what the Northern Ireland housing market needed. It’s proof that passive house construction works here, that it can be done at scale, and that the economics make sense.

If you’re thinking about building a new house, the question isn’t whether you can afford to build to passive house standard. With energy prices where they are, the question is whether you can afford not to.

The upfront costs are real, but they’re not ridiculous. The long-term savings are substantial. The comfort and air quality benefits are genuine. And you’re future-proofing yourself against whatever happens to energy prices over the next 30 years.

For most people, Lancaster Park represents something more important than another housing development. It’s proof that we can build homes that barely need heating, right here in Belfast, for prices that aren’t completely mad. That changes everything.

See where passive house construction ranked in our definitive guide to sustainable building methods.