The colder your climate zone, the lower the U-value the building code demands — and the more capable (and pricier) the glazing has to be. Pick your province to see the U-value your windows must meet and an illustrative installed cost. These are code-derived estimates, not market quotes — use the calculator for an exact price for your size.
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Get the embed codeIn Spain the price of a compliant window is not set by taste — it starts with regulation. The Código Técnico de la Edificación works like a chain: your municipality gets a climate zone, the zone caps the window U-value, and the cap decides the glazing package you have to buy.
CTE DB-HE1 assigns every municipality a zone: a letter for winter severity — α (the Canary Islands) through E (the coldest inland provinces) — plus a number for summer. It is derived from the province capital's climate, corrected for altitude.
Each winter letter caps the transmittance of openings (table 3.1.1.a-HE1): from ≤ 3.2 W/m²·K in zone α down to ≤ 1.8 in zones D and E. Replace windows in works that must comply with the code, and your new units have to meet the cap.
The cap dictates the spec: standard double glazing passes in the mildest zones, low-e double with argon in B and C, triple or high-spec low-e in D and E. That spec — plus the frame able to carry it — is what moves the installed price from province to province.
The same table the map is drawn from: the real CTE U-value cap per winter zone, the glazing that typically meets it, and the illustrative installed cost of a code-compliant ~100×100 cm unit.
| Winter zone | Provinces | Max U-value (W/m²·K) | Glazing to meet it | Illustrative cost, installed* |
|---|---|---|---|---|
| α | Las Palmas, Santa Cruz de Tenerife | ≤ 3.2 | Standard double | €320–€610 |
| A | Almería, Cádiz, Huelva, Málaga +1 more | ≤ 2.7 | Standard double | €335–€640 |
| B | Alicante, Balearic Islands, Castellón, Ceuta +5 more | ≤ 2.3 | Low-e double + argon | €355–€680 |
| C | A Coruña, Badajoz, Barcelona, Biscay +7 more | ≤ 2.1 | Low-e double + argon | €380–€725 |
| D | Álava, Albacete, Asturias, Ciudad Real +17 more | ≤ 1.8 | Triple / high-spec | €410–€780 |
| E | Ávila, Burgos, León, Soria | ≤ 1.8 | Triple / high-spec | €435–€830 |
*Per ~100×100 cm unit, from efficient PVC to thermal-break aluminium. Code-derived estimates, not market quotes — the exact price depends on size, opening type and installer.
The map gives the regional ballpark. For your exact window, design it in the calculator and get real quotes from verified installers near you.
It depends on your CTE climate zone. The building code (CTE DB-HE, table 3.1.1.a-HE1) caps window transmittance at 3.2 W/m²·K in the mildest zone (α — the Canary Islands), 2.7 in zone A, 2.3 in B, 2.1 in C and 1.8 in zones D and E. The map shows the exact cap for every province; it applies whenever you replace windows as part of works that must comply with the code.
A two-character code the Código Técnico de la Edificación assigns to every municipality: a letter for winter severity (α, then A up to E, the coldest) and a number for summer severity (1–4). It is derived from the province capital’s climate, adjusted for altitude. The zone drives the envelope requirements — including the window U-value cap — so it is the single biggest regulatory input to your window spec.
Because the code demands a lower U-value there, and hitting it takes more capable hardware: low-emissivity coatings, argon fill, warm-edge spacers, better frames — and in zones D and E often triple glazing. On the map's illustrative scale, the same ~100×100 cm installed unit runs from about €320 in the Canary Islands to about €830 in the coldest zone-E provinces.
No — they are code-derived estimates, clearly labelled as such: national installed-price data for efficient PVC and thermal-break aluminium, scaled by each zone’s U-value requirement. Your real price depends on size, opening type, glazing and installer. For an exact figure, design your window in the calculator and get quotes from verified installers in your province.
Not always — the code sets a performance cap, not a technology. Where windows must stay at or under 1.8 W/m²·K (zones D and E, including Ávila, Burgos, León, Soria and much of the central plateau), you need triple glazing or a high-spec low-e double in a good frame. In zones B and C a low-e double with argon passes comfortably, and in the mildest zones a standard double can still comply — though low-e usually pays for itself in comfort and bills.
Yes. Energy-efficient window replacement qualifies for a regional grant of up to 40% (capped at €7,500 per dwelling under the Plan Estatal de Vivienda 2026–2030) and an IRPF tax deduction of up to 40%, which for individual dwellings ends 31 December 2026. Estimia's subsidy & deduction calculator stacks both for your province and shows the honest net figure.
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