What to expect
| Typical duration | Measure to install 6–12 weeks including manufacture and crossing |
|---|---|
| Cost band | Figures live in the cost index |
| Permit required | Changing opening sizes needs a permit · appearance controlled in settlements |
| Seasonal constraint | Install off-season for hotels and rentals |
Wind is a structural load, not a comfort issue
On the caldera rim, the south coast and the high inland ground, sustained wind is a design load. It governs frame section, glass thickness and — most importantly — the fixing back to structure.
- Large sliding units facing the caldera are the most exposed elements on the building. Frame and glass specification follow from the actual exposure, not from a standard domestic catalogue.
- Fixings into structure, at the correct centres, with the correct anchors for the substrate. Fixing a heavy sliding unit into a rubble stone wall is not the same as fixing into concrete.
- Weathering and drainage in the frame, because wind-driven rain arrives horizontally here and a system that drains against gravity alone will let water in.
- Restrictors and safe opening on exposed terraces, where an unrestrained door in a gust is a hazard.
Hardware fails first
The frame outlasts everything attached to it. Hinges seize, rollers corrode, multi-point locks jam, and handles pit. On a rental that means a guest cannot close a door, which becomes an urgent call in August.
- Marine-grade or coated hardware where the property is anywhere near spray — the premium is small against replacing a lock in season.
- Serviceable, obtainable hardware. Exotic hardware that has to be ordered from abroad and shipped by ferry is a poor choice on this island regardless of quality.
- An annual service for rentals and hotels: clean tracks, lubricate, adjust and check seals, before the season rather than during it.
What you are allowed to fit
In a designated traditional settlement, windows are one of the most tightly controlled elements. Proportion, subdivision, material, colour and whether shutters are required can all be prescribed, and replacing traditional timber openings with large modern glazed units is frequently not permitted.
This is worth checking before ordering anything. Manufactured units that do not comply are an expensive mistake — they are made to size and cannot be returned. See traditional settlement compliance.
Material choice, honestly
| Material | Strengths | Weaknesses here |
|---|---|---|
| Aluminium (thermally broken) | Strong sections for large spans and wind loads; good in exposed positions; long frame life | Coating damage near spray needs care; cheaper systems perform poorly thermally |
| uPVC | Cost, thermal performance, low maintenance | Section sizes limit large spans; UV over long periods; not usually acceptable in protected settings |
| Timber | Required or preferred in many designated settlements; repairable; correct appearance | Genuine maintenance cycle in this climate |
| Timber–aluminium composite | Correct appearance inside, durable outside | Cost, and lead time |
Questions people actually ask
Can I replace my timber windows with aluminium?
Outside a designated settlement, usually. Inside one, frequently not, or only in a form that reproduces the original proportion and appearance. Check before ordering — made-to-measure units cannot be returned.
My sliding door is hard to move. Can it be fixed?
Usually. It is normally corroded or worn rollers and a dirty track rather than the door itself, and it is much cheaper to service than to replace. Left long enough it does damage the track, at which point it becomes expensive.
Do I need shutters?
They are extremely effective here — external shading stops solar gain before it enters the building, which internal blinds cannot do. In some settlements they are also part of the required appearance.
How long from ordering to installation?
Six to twelve weeks typically, including manufacture and the crossing. It is one of the items most likely to govern a programme, so it is frozen and ordered early.
Is triple glazing worth it?
Rarely here. The problem is summer solar gain, not winter heat loss, so solar control glass, external shading and good sealing deliver far more than an extra pane.