Energy rating A or B in a new build: is it worth paying more?

The sticker comes almost last. You sign, you collect the keys to your new flat in Villajoyosa or on Alicante's Gran Via, and inside the folder sits a colour-coded label with one big letter. Almost always an A. Sometimes a B. Rarely anything worse.

And there the question every new-build buyer faces is born: if the building is already efficient, does it make sense to pay the premium the developer asks to move from B to A? The short answer: it depends on how many years you plan to live there and whether you will ever sell. The long answer is below.

What that letter really measures

The energy performance certificate does not grade how pretty your home is. Under Royal Decree 390/2021 it measures two things: non-renewable primary energy consumption, in kWh per square metre per year, and CO2 emissions, in kilos per square metre per year. With those two numbers a technician places the home on a scale running from A, the most efficient, to G, the most wasteful.

An A does not mean you pay no electricity. It means your home needs very little bought energy to keep you at twenty-two degrees in January and cool in August. The certificate lasts ten years, unless the grade is a G, in which case it is valid for only five. In a new home that document is almost a formality, because the law already forces good building.

Why your new build is already an A or B

Since 31 December 2020, every newly built home in Spain must be a Nearly Zero-Energy Building (NZEB). This is required by the DB-HE technical document of the Building Code, which caps non-renewable primary energy per square metre by climate zone. Alicante sits in zone B4: mild winters, long summers. That works in your favour, because heating costs little and the real challenge is cooling.

That is why buying off-plan and finding a C is now very rare. The starting point is a B, and many developments reach an A by adding aerothermal systems, rooftop solar and a well-insulated envelope. If you want to understand the rating letter by letter, we break it down in the A rating explained.

The real difference on your bill

This is where the letter turns into euros. Homes rated A or B spend, on average, 60% less on heating and cooling than those built before the year 2000. It is not magic: it is insulation, windows that seal and efficient equipment.

On the Costa Blanca the heart of that efficiency is usually the aerothermal system. Against a gas boiler it saves around 275 euros a year in a 150 square metre home, and close to 990 against diesel. Add Alicante's 300-plus days of sun driving panels on the roof and you see why an A here delivers more than the same A in the rainy north. In an average Costa Blanca flat, that efficiency shows up as cooling bills that rarely alarm, even in the middle of August with the air conditioning on. We explain how this kit works in this guide to aerothermal and underfloor heating.

What an A adds to resale value

Efficiency is no longer just comfort: it is market value. A Bank of Spain study published in 2025 found that a high-rated home (A or B) sells, on average, 9.7% dearer than an equivalent low-efficiency one (F or G) between 2015 and 2022. And the gap is widening: it was 5.4% in 2017 and reached 18.3% in 2022.

Per square metre, A-labelled homes hovered around 2,064 euros, against 1,214 for a G. In detached villas, the kind that fill Finestrat or La Nucia, the jump is even larger: up to 19.5%. Buying an A today partly shields your resale tomorrow.

The green mortgage: a hidden 0.1%

There is a quiet benefit in buying an A or B home: the green mortgage. Several banks apply an interest-rate discount to buyers who finance an efficient house, on the logic that whoever spends less on power has more room to pay. The average cut is around 0.1%. Triodos Bank ties the spread directly to the energy rating, and BBVA markets its Efficient Home Mortgage for homes labelled A or B.

It sounds small, but it holds for the entire life of the loan, and to qualify you only need to present the energy performance certificate. This is not personalised financial advice: every bank changes its terms, so confirm it with your lender or an adviser.

So, should you pay the premium for an A?

Three questions settle the maths. Will you live in the home for many years? Then the savings on bills and that 0.1% mortgage end up covering the extra. Do you plan to resell? The 9.7% value premium outweighs the initial cost. Does the developer move from B to A with real upgrades, such as more solar panels or better insulation, and not just a change of paper? If so, the answer is yes.

If instead you are buying for a short spell and a B already does the job, stretching the budget may not be worth it. In a new build, we insist, neither option is bad: you start from a home that is already efficient by design. A good example is this new-build apartment in Villajoyosa, with today's energy standards built in.

At ESYS VIP we help you read the fine print of every development. Explore our properties or contact us and we will look at it together.