🇪🇸 Spain · Roofing · Updated 2026
How much roofing do you need to build a house in Spain?
A 150 m² single-storey house in Spain needs roughly 209 m² of roofing — about 1.39 m² per m² of floor area. That is computed from Spain construction conventions, including the local wastage allowance.
Roofing quantities for a house in Spain, computed from how buildings are actually put up here rather than from a global average. The tables below run from a small 50 m² dwelling to a 400 m² family home, and the method section shows how to reproduce every figure by hand so you can adapt it to your own plan.
Roofing by house size in Spain
| Floor area | Roofing required | Per m² of floor |
|---|---|---|
| 50 m² | 77 m² | 1.54 |
| 75 m² | 110 m² | 1.47 |
| 100 m² | 144 m² | 1.44 |
| 150 m² | 209 m² | 1.39 |
| 200 m² | 274 m² | 1.37 |
| 250 m² | 339 m² | 1.36 |
| 300 m² | 403 m² | 1.34 |
| 400 m² | 530 m² | 1.32 |
Single-storey. The per-m² rate falls as the house grows — a small house has more wall and roof per square metre of floor than a large one, which is why these are computed size by size rather than scaled from a single rate.
Where it goes — 150 m² house
Roof covering area 173 m² plan opened out at 25° plus 10% laps | 209.4 m² |
Fascia, barge & rainwater goods Perimeter plus gable rake | 57.5 m run |
What drives the quantity in Spain
| Factor | Local value | Effect |
|---|---|---|
| Roof pitch | 25° | Pitch converts plan area to real surface: at 25° the roof is about 1.10× the plan area beneath it. |
| Eaves overhang | 450 mm | Overhang adds covering area all the way round and is routinely left out of quick estimates. |
| Laps | ~10% | Side and end laps on sheeting, or headlap on tiles. Never covered by the geometric area. |
| Climate | subtropical | Rainfall intensity and UV exposure drive covering choice and gutter sizing more than load does. |
How to calculate it yourself
- 01
Take the plan area of the building and add the overhang all round (0.45 m here).
- 02
Divide by cos(25°) — a factor of about 1.103 — to get the true sloping area.
- 03
Add about 10% for laps and cutting at hips and valleys.
- 04
For sheets, divide by the cover width (not the overall width) of the profile you are buying, then round up to whole sheets of the right length.
- 05
Measure gutters, fascia and barge boards on the perimeter separately — they are priced per metre run, not per m².
Buying and site notes
- —Order sheets cut to the full rafter length where possible. Every end lap is a leak waiting to happen and adds material.
- —Fixings are not a rounding error on a large roof — count them, especially in high-wind areas where the fixing schedule is prescribed.
- —Check the gutter and downpipe sizing against local rainfall intensity, not against habit.
Get every material measured off your own plan
This page works from a representative footprint. Upload your dimensioned drawings and get the full schedule — every material, measured from your real geometry and priced in EUR (€).
Take off my drawingsRoofing in Spain — frequently asked
How much roofing does a house need in Spain?
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A 150 m² single-storey house in Spain needs roughly 209 m² of roofing — about 1.39 m² per m² of floor area. That is computed from Spain construction conventions, including the local wastage allowance.
How much roofing per square metre in Spain?
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About 1.39 m² per m² of floor area for a single-storey house. The figure is not linear across sizes — a small house has proportionally more wall and roof per m² of floor than a large one, which is why the table above is computed size by size rather than scaled from one rate.
What changes the quantity of roofing needed?
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Roof pitch (25°) — Pitch converts plan area to real surface: at 25° the roof is about 1.10× the plan area beneath it. Eaves overhang (450 mm) — Overhang adds covering area all the way round and is routinely left out of quick estimates. Laps (~10%) — Side and end laps on sheeting, or headlap on tiles. Never covered by the geometric area.
Is wastage included?
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Where it applies, yes — a 5% allowance is carried on the perishable materials (walling units, tiles, paint). Bulk materials like sand and stone carry handling loss instead. Ordering the theoretical quantity with no allowance reliably means a second delivery at a worse price.
How accurate is this for my own house?
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It is a planning quantity derived from a representative rectangular footprint, so it is the right order of magnitude and internally consistent — good for budgeting and for checking a supplier's list. It is not a measured takeoff of your plan. Upload your dimensioned drawings to get quantities measured off your real geometry and priced in EUR.
Are roofing prices included?
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No, deliberately. Material prices in Spain move week to week and vary by region, so a price printed on a static page would be wrong within a month. This page gives you the quantity — take that to two or three local suppliers and the price will be current and competitive.