Design & Architecture · 8 min read
2026 Construction Costs
A cost per square metre describes the shell. The villa opens in the joinery, the stone fixing, the services and whether the garden is in the contract.
Updated: 2026-11-04
A cost per square metre is not the total of a house. It usually describes the shell: the concrete frame, the wall infill, the roof. A villa does not finish in that figure. The joinery, the way the stone is fixed, whether the services are drawn, and whether the garden is inside the contract split the same area into two accounts.
The square-metre figure describes the shell
What is usually counted in a cost per square metre is the shell. Columns, beams, slabs, the infill of the external wall, a flat roof, and sometimes a ready-made window. Plaster and paint are in some quotations and absent from others. A figure given without those lines is the cost of a shell, not of a house.
Setting that figure beside a villa quotation compares two different buildings. In the villa the joinery is made for the opening, the façade may not be a coat of plaster, the roof carries the water away through a detail, and the services are tied to a drawn fitting. The same square metre is another building in the second account.
A ready-made window and a bespoke system
A ready-made window arrives to the size of the opening, and the wall is built to suit it. In a thermally broken aluminium system made for the house, the profile, the build-up of the glass, the corner junction and the sill are separate lines. Both are called joinery. In the account one is a single item and the other is a fabrication.
The ready-made window is the right line when the opening is small and the frame sits inside the wall. When the glass runs from floor to ceiling and the corner has to meet without a post, the system is made for that span. The money goes to the profile, the glass and the making of that corner. A thin profile leaves the landscape. A deep frame brings the wall back.
Stone is not a cladding line
A natural-stone façade is not a cladding line. The thickness of the stone, the fixing, the subframe, the corner, the sill and the joint change both the stone and the labour on the same area of façade.
A plate of about twenty millimetres stuck onto a plastered wall lowers the first line. That plate does not do the work of the wall. Mechanically fixed stone brings the subframe, the anchors and the waste into the account.
One floor area, two accounts
Two villas can share a floor area and still be two buildings. One ends with the concrete shell, plaster, a ready-made window and a flat roof. The other, on the same slab, carries a stone façade, joinery made for the opening, a roof that takes the water down, a drawn lighting plan, and a pool written as its own scope. The area is the same. The number of lines in the account is not.
On the coast the metal splits as well. Bare iron rusts in the salt and the fixing is taken out a second time. Stainless steel or painted aluminium is a larger line in the first account. If that line was never written, the square-metre figure never counted the salt.
What is locked before quotations
Four scopes are written before a quotation is asked for. The shell: foundation, concrete frame, roof. The envelope: wall, insulation, water, façade, joinery. The services: heating, cooling, electrical, lighting, water. The external works: terrace, drainage, retaining wall, pool, landscape. A square-metre figure that arrives before those scopes are written makes the missing work look cheap.
The decisions sit here. Is the stone fixed mechanically, or is a plate stuck on? Does the joinery arrive ready-made, or is it made for the opening? Where does the roof water go? Is the pool inside this contract? Without those four answers, two contractors' quotations cannot be read side by side. One has priced the shell. The other has priced the house.
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