How much does it cost to renovate windows in a T4 villa in the Algarve?

📅 15 May 2026 · ⏱ 9 min read · ✍️ Carlos Carrondo

It is the question we hear most on the phone: "roughly, what will it cost to replace all the windows in the house?". The honest answer is "it depends" — but that helps nobody plan. So instead of dodging the number, let us open the quote of a real T4 villa, piece by piece, based on what we invoiced in Vilamoura, Almancil and Loulé over recent months.

First: what counts as a "T4"

A T4 in the Algarve rarely has just 4 windows. Counting the openings properly — bedrooms, suites, living room, kitchen, bathrooms, stairs, front door, terrace doors — a typical T4 villa has between 16 and 22 openings. Total frame area is usually 28 to 45 m².

It is this area, not the number of rooms, that drives the price. Two T4 villas can have quotes €8,000 apart simply because one has panoramic sliding doors to the garden and the other has small casement windows.

The price per m² in 2026

In aluminium with thermal break and low-e double glazing — the minimum we recommend in a coastal zone — the 2026 installed figures are:

These figures already include manufacturing, glass, German fittings, coating, transport and installation. They do not include builder's work (widening openings, new lintels) or scaffolding when the facade requires it.

A real T4 quote (Almancil, early 2026)

Two-storey villa, 19 openings, 38 m² of frames. Aluminium with thermal break, 4+16+4 double glazing with argon and low-e, Qualicoat Seaside coating (3 km from the sea), Roto fittings.

• 11 casement / tilt-and-turn windows (bedrooms, bathrooms) — €9,400
• 3 sliding terrace doors (living room and suite) — €6,800
• 2 panoramic fixed lights (stairs and hall) — €2,100
• 3 kitchen and laundry windows — €2,300
• Removal, fitting, foam, silicone, finishing — €1,900

Turnkey total: €22,500 + VAT. This villa landed in the upper-middle third because it has a lot of large sliding openings. A more "closed" T4 with small windows would land near €13,000–15,000.

Rule of thumb: to estimate before the visit, count the openings, multiply by the average area (≈ 2 m² each) and by €380/m². For a T4 this usually gives €12,000 to €26,000. The site visit then fine-tunes it to the euro.

What pushes the price up (and what not to cut)

Pushes it up, rightly

• Large sliding openings — reinforced profile, more glass, lift-and-slide hardware. A 4 m opening costs more than triple a 1.2 m one.
• Certified Seaside coating — €15 to €25/m² above normal paint. Within 2 km of the sea it is not optional: it is what separates intact coating at 10 years from peeling at 4.
• Triple glazing or solar-control glass — makes sense on south/west openings where heat really enters in the Algarve summer.

Where cutting costs you later

Generic fittings, 4+12+4 glass without gas, no thermal break "to save money". That is where the window is born that condenses inside, creaks by year three and forces a full re-do — and replacing a badly made window costs 40 to 60% more than doing it right the first time.

Scaffolding, builder's work and what cheap quotes hide

An honest quote states clearly what it does not include. The costs that appear "later" in cheaper proposals:

• Facade scaffolding — needed on high floors or inaccessible openings. €600 to €1,800 on a villa, depending on height and days.
• Lintels and openings to redo — when an opening is enlarged or the old lintel won't hold. Builder's work, separate.
• Shutters and mosquito screens — often requested at the end. Thermal aluminium shutters run €120 to €380/m².
• Stone sills and finishes — in old-house renovations, rarely in the base quote.

Timelines: when will this be done?

For a standard T4, from "yes" to "house finished":

• Site visit and detailed quote: 24 to 48 h
• Workshop manufacturing after order: 3 to 4 weeks
• On-site installation: 5 to 7 working days

Realistic total: 5 to 7 weeks. If there is a conservatory needing a council permit, add 4 to 8 weeks of council process — so it pays to request the permit at the very start.

And the 2026 state grants?

If you are a Portuguese tax resident, replacing windows with efficient models can be co-funded: Vale Eficiência (€1,300) and Fundo Ambiental (up to €7,500). On a T4 this can take €5,000 to €8,000 off the net investment. We explain the process step by step in our 2026 grants guide.

Honest summary

A T4 in the Algarve, all windows replaced, aluminium with thermal break and low-e glass, turnkey: €12,000 to €28,000. The exact number depends on how much large sliding opening it has. The only serious way to know yours is a site visit — which is free, takes 30 minutes and gives you a quote to the euro within 24 hours.

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