Your Home Pays You Back: The Energy Savings Math
Every potential homebuyer we talk to asks some version of the same question. Sounds lovely. How does this actually work financially?
It’s the right question.
Here’s the honest answer.
The Short Version
A NeighbourWood home will carry three annual fees — estate management (€850), woodland stewardship (€850), and energy infrastructure (€520). Total: €2,220 per year.
That same home is designed to save a household between €3,220 and €5,010 per year in direct, everyday costs. Energy bills. Water softening. Appliance longevity. The kinds of things that hit your bank account every month, whether you pay attention or not.
The difference — between €1,000 and €2,790 per year in your pocket — is the conservative case. Before mortgage savings. Before avoided retrofit costs. Before the value of living somewhere with permanent native woodland linked to the home.
Let me show you where those numbers come from.
Where the Savings Come From
The energy bill. This is the biggest category, saving between €2,600 and €3,900 per year compared to a typical Irish home. A NeighbourWood home will be built to BER A1 standards with Passivhaus specification, heated by a heat pump, and topped with a 6 kWp solar array feeding a 10 kWh battery. The building envelope does most of the work: a home this airtight and well-insulated requires roughly a tenth of the heating energy of an older Irish home. The heat pump then delivers that reduced demand at three to four times the efficiency of a gas or oil boiler. The solar and battery cover most of the remaining electricity. The gap between a NeighbourWood electricity-and-heat bill and a typical Irish equivalent is large, and it grows every time energy prices do.
We’ve covered the technical side of this elsewhere (“How We Build” gets into the specifics). Here, the relevant point is that the saving is structural, not behavioural. You don’t have to remember to turn things off.
Water. Every NeighbourWood home will include whole-house water softening and treatment. Most Irish homes don’t have this. The savings here are smaller per line but add up: a heat pump running on softened water stays efficient for longer (limescale is the enemy of heat exchangers), appliances last measurably longer, you use less detergent and soap, and you avoid occasional plumber visits for descaling. Together, these account for roughly €600 to €1,100 per year.
The total. Add energy and water savings together, and the conservative range lands between €3,220 and €5,010 per year. That’s before anything fancy.
What Varies, What Doesn’t
Numbers like these always carry a range, and the reasons for the range matter.
What varies: household size, occupancy patterns, energy prices, hot water use, driving patterns for the EV charger, how warm you keep the house in January. Someone who heats their home to 22°C and does a lot of laundry will save more than someone who keeps it cool and travels often. The range reflects that reality.
What doesn’t vary: the fees. €2,220 per year is €2,220 per year. The fees are predictable and contractual, which is part of what makes the math work — you can budget against them.
The ranges in the savings are genuinely conservative. They’re modelled against current Irish energy prices, current water costs, and actual performance data from Passivhaus homes built elsewhere in Ireland and the UK. The first five pilot homes will verify the model against measured reality, and we will publish what we find — favourable or not.
The Bigger Picture
The €1,000–€2,790 net annual benefit is the conservative case. There are two other benefits worth knowing about, even though they’re harder to quantify precisely for any specific household.
Green mortgage rates. Most Irish lenders now offer discounted rates for BER A1 homes — typically 0.8% to 1.2% below standard variable. On a €450,000 mortgage, that’s roughly €2,460 per year in lower interest payments. Your specific rate will depend on your lender and your circumstances, but the industry direction is clear: high-efficiency homes will continue to command better mortgage terms, not worse.
Avoided retrofit. Ireland’s building regulations are moving toward Zero Emissions Building standards by 2030. Typical Irish homes sold today are likely to face retrofit costs of €50,000 to €100,000 by 2035 to remain compliant or saleable. A NeighbourWood home will be ZEB-compliant from day one. That bill never arrives.
Layer those in and the realistic annual advantage rises to somewhere between €6,760 and €11,850.
Over the life of a 25-year mortgage, that’s real money.
Why I Keep Saying “Will” and “Designed To”
You’ll notice I’m writing much of this future tense. Because these homes don’t exist yet.
The math is built from real specifications, real pricing data, and real performance benchmarks from Passivhaus homes elsewhere — it’s not guesswork, but it’s also not measured outcomes from our own pilot. The first five homes in County Wicklow will either confirm the modelling or tell us where to adjust.
That’s the test. It’s also why Esther and I will buy one of those homes and live in it ourselves. If the math is wrong, we’ll feel it first.
The Question Behind the Question
Most people who ask how does this work financially? are really asking is there a catch?
The honest answer is that the economics work because the design is built around them. Net-zero homes are designed to be cheap to run. Water treatment is designed to protect the equipment that makes them cheap to run. The fees are designed to fund permanent infrastructure — the woodland, the estate, the systems — not to extract rent. Every fee has a real job.
What you’ll get, in the end, is a home that costs less to live in, carries less future risk, and anchors a community to permanent native woodland. The math works because the design is right.
NeighbourWood Communities is building Ireland’s first net-zero woodland communities. Register your interest for updates, priority access, and an invitation to visit when construction begins.