Insight / Curtain Wall Cost per M²
Cheapest now, most expensive later.
Curtain wall cost per square metre is not one number. A handful of things drive it on every project, along with what a cheap quote quietly leaves out.
Where the cost actually goes
These five things account for most of the spread between quotes, before a single square metre is installed.
Building height
The taller the building, the greater the wind load the mullions and glass must resist, and the harder access for installation and maintenance from a gondola becomes. Height raises the cost per square metre, so two buildings with the same facade area can price very differently.
Glass type
Single-pane, laminated, and double-glazed glass differ sharply in price, and glass is often the largest single gap between two quotes for facades that look alike. Curtain wall glass is generally 8 to 12 mm as a single layer, and thicker where laminated or double glazing is used.
Floor-to-floor span
The span between floors sets the depth of the mullion profile. A wider span demands a deeper, heavier profile, and that adds aluminium directly to the bill.
Facade shape
A flat facade with repeating panels can use a unitized system assembled in the factory. A curved or stepped facade needs unique panels one at a time, which removes the repetition that makes unitized cheaper per unit.
System: stick or unitized
The two systems shift cost between material, labour, access equipment, and time. Unitized is usually cheaper overall above roughly ten storeys, where panels repeat and site installation time becomes the constraint. Below that, stick is often more economical.
What the per-square-metre number covers, and what it does not
Two very different things get quoted as a curtain wall price: the labour to fit the panels, and a facade package that has been calculated and detailed in full. The numbers being compared are often not the same number.
An installation price per square metre usually covers the panel and the labour to fit it. The frame behind it, the detailing at the glass interface, and responsibility if it leaks later sit outside that figure.
Two quotes can name the same figure per square metre for entirely different scopes of work. One stops at installation. The other calculates wind load, designs the joint detail, and carries the water-tightness responsibility through to handover.
Why the cheapest can end up the most expensive
The cheapest quote usually reaches its number the same way every time.
The glass gets thinner, the mullion gets smaller, or a cheaper sealant goes in. The target is lowered until the number fits the budget, and the result is genuinely cheaper on paper.
The cost that was cut does not disappear. It reappears a few years later, as a leak, as glass that cracks under a wind load that was never fully calculated, or as a profile that has to be taken apart to repair.
Value Engineering runs the other way. The target holds, and the work goes into finding a different arrangement of the system that reaches it for less. That difference only shows years after handover, long after the quote was opened.
Questions we get asked
Most come from owners and project teams comparing quotes.
- How much does curtain wall cost per square metre?
- There is no single figure that applies to every project. The number comes from building height, glass type, floor-to-floor span, facade shape, and the choice between stick and unitized. We calculate all five first, then give a figure.
- Why can two curtain wall quotes differ so much for the same building?
- Because the two usually price a different scope, not a different system. One quote can stop at panel and installation, while the other calculates wind load, designs the joint detail, and carries the leak risk.
- What is included in a curtain wall installation-labour price?
- An installation-labour price usually covers only the panel and the labour to fit it. The frame behind it, the structural calculation, and responsibility for water tightness generally sit outside that figure, so they are worth asking about separately.
- Why can choosing the cheapest option end up costing more?
- Because the cheapest figure is usually reached by lowering the performance target, not by finding another route to the same target. The saving shows up on the quote, and the cost returns later as a repair or a replacement.
- When is the right time to ask about curtain wall cost?
- As early as possible, while the facade design is still a drawing and has not been locked into shop drawings. A change at this point adds almost no cost, while a change after profiles are ordered eats into the saving it was meant to produce.