A higher energy rating makes your home worth more. Full stop.

You buy a house. Great. Character. Potential. But the energy rating is D. Then come the well-meaning comments: “Just live in it for a while first.” “You can always make it more sustainable later.” And the classic: “Do you know how much all that costs?” It is not an unreasonable reaction. Buying a house is expensive enough as it is. Insulation, a heat pump or solar panels can easily feel like investments that can wait.

But that is exactly where the misconception lies. Making your home more sustainable is not just about spending money to reduce your energy bills. It also changes the house itself. It becomes more comfortable, more energy-efficient and increases the value.

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An energy rating is no longer a minor detail

Recent research by Brainbay shows that homes with better energy ratings are consistently worth more than comparable homes with low ratings.

And that difference is growing. Not slightly, but significantly.

At the beginning of 2021, a comparable home with an A rating was worth around 6% more than one with a G rating. That gap has now widened to more than 17%. At the beginning of 2026, Brainbay calculated an average value of approximately €4,400 per square metre for an A-rated home, compared with around €3,750 for a G-rated one.

Of course, that does not mean you can spend €10,000 on insulation and be €74,000 richer the next day. Property values do not work that way. But it does demonstrate something important: buyers are willing to pay more for an energy-efficient home.

An energy rating is therefore no longer just the coloured letter tucked away at the bottom of a Funda listing. It is increasingly reflected in a home’s price.

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But does making your home more sustainable actually increase its value?

That may be the most interesting question of all.

It is one thing to say that an A-rated home is worth more than a comparable G-rated property. But what happens when you invest your own money in insulation or a heat pump?

Brainbay investigated this too, in a study commissioned by the Dutch National Mortgage Guarantee scheme (NHG). The study analysed 15,000 homes below the NHG price limit with energy ratings ranging from B to G. It compared the cost of sustainability improvements with the estimated increase in property value.

The results are striking.

Among homes that were fully insulated, the estimated increase in value was at least equal to the amount invested in 85% of cases.

On average, the estimated increase in value was equivalent to 196% of the cost of the improvements.

The effect was also clear for homes where insulation was combined with technical upgrades, such as a new boiler or a hybrid or fully electric heat pump. In 88% of these homes, the estimated increase in value was at least equal to the investment.

Homes with poor energy ratings showed particularly strong potential. Of the homes with an E, F or G rating that received both insulation and technical upgrades, more than 94% achieved an estimated increase in value that was at least equal to the amount invested.

That does not mean every euro you spend on sustainability improvements is guaranteed to add two euros to your home’s value. Every property, size and situation is different.

But it does show that making your home more sustainable is not simply an expense.

Some of the money you invest in your home today may return to you later through a higher property value.

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Yet a new kitchen often feels more appealing

Why are we so quick to postpone sustainability improvements? Because other renovations are much more tangible. You see a new kitchen every morning. A beautiful bathroom feels luxurious. With an extension, you know exactly what you are getting in return. Cavity wall insulation? That is considerably less exciting.

You spend a couple of thousand euros, a van pulls up outside and, at the end of the day, your home looks almost exactly the same. That makes sustainability improvements feel like an expense.

But financially, that view is becoming increasingly difficult to justify. Doing nothing has a price too. You can keep the money in your bank account, nevertheless you also keep your higher energy bills, lower level of comfort and poorer energy rating.

Energy-efficient homes are consistently worth more. If you do not make your home more sustainable, you may be leaving some of that value on the table.

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And then there are the subsidies

Subsidies were not taken into account in the study, even though financial support is often available for measures such as insulation, glazing, and heat pumps. 

As a result, your actual investment may turn out to be lower than the figures on which the estimated increase in value is based.

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Prets gives you insight

The problem is that piecing together that full picture can be complicated. That is where Prets can help. We bring the different financial options together, allowing you to quickly see what sustainability improvements will cost, which subsidies and financing options are available and what your investment could deliver.

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A poor energy rating? That is where the potential lies

Why wait to make an investment that improves your comfort from day one, can save you money every month and may partly return to you through a higher property value?