Unitised curtain walling
Unitised curtain walling arrives on site as complete storey-high panels, usually one or two glass widths wide, already framed, glazed and sealed in a factory. Each panel is lifted by crane or a floor-mounted hoist and hooked onto brackets at the slab edge, where it interlocks with the panels beside and below it.
Because the glazing is done indoors under controlled conditions and very little work happens on the outside face, unitised systems are the usual choice for tall offices, residential towers and hotels.
Guide price: £1,400 to £1,600 per m²
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When unitised is worth the premium
- Buildings of roughly seven storeys or more, where scaffolding the whole height would be slow and costly.
- Tight city sites where the facade must be closed in fast to let internal trades start.
- Repetitive elevations with a small number of panel types, so factory set-up pays back.
- Projects that need high and consistent air and water performance from controlled factory glazing.
- Sites where most installation can be done from inside the building, floor by floor.
- Designs with integrated fins, shading or spandrel cladding that are easier to build on a bench.
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What unitised curtain walling costs
| Item | Typical figure, ex VAT |
|---|---|
| Unitised curtain walling, flat Proprietary system, powder coated or anodised, beaded glass, supply and install | £1,400 to £1,600 per m² |
| Solar control coating instead of plain low-e Extra over the base rate | £65 to £75 per m² |
| Laminated inner pane (heat strengthened) Extra over | £65 to £75 per m² |
| Structural silicone flush face (unitised) Extra over, no external beads or caps | £90 to £100 per m² |
Where these figures come from
Per m² rates are for a proprietary aluminium system on a flat elevation, supply and install, excluding VAT, from the RIBA Journal cost guide by Gleeds (March 2025). They do not include scaffolding or access, preliminaries, design fees or testing. Public contract figures are the awarded value on each Contracts Finder notice and cover the whole package described.
Pricing a unitised package for a tall building? Send us the outline and we will look for a specialist with the factory capacity for it.
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What makes unitised different
The panel joints, the factory and the lifting plan are where unitised projects succeed or slip.
Interlocking stack joints
Each panel has male and female profiles on its edges. As a panel is lowered, its sides engage with the panel next to it and its bottom engages with the panel below, forming a split mullion and a stack joint at each floor. These joints take up the building's movement, including slab deflection and thermal expansion, without the seals being torn.
Because the joints are made by gaskets rather than wet sealant on site, the quality of the factory work and the accuracy of the brackets decide how watertight the wall is.
Programme and lead times
The work is front-loaded. Design, testing of a mock-up and factory production all happen before anything arrives on site, so a unitised package needs to be let early. Once panels start arriving, a team can close in floors quickly, which is where the programme saving comes from.
Ask tenderers for their design period, the mock-up test date, factory output per week and the installation rate per floor, and check them against the main programme.
Higher-risk buildings
In England, residential buildings of at least 18 m or seven storeys with two or more homes are higher-risk buildings. Building work on them goes to the Building Safety Regulator as building control, and the external wall faces the material rules in regulation 7(2). Glass and frames are exempt from the non-combustible rule, but insulation in spandrel panels, backing boards and many other parts are not, so the panel build-up has to be checked line by line.
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How a unitised package gets done
Design and mock-up
The specialist designs the panel types, then a full-size mock-up is tested for air, water and wind to the agreed sequence.
Factory production
Frames are cut, assembled and glazed indoors; each panel is checked and labelled for its position.
Brackets and lifting
Brackets are set out on each slab; panels are lifted in, hooked on and interlocked, floor by floor.
Seal, test, hand over
Stack joints and interfaces are completed, sample areas hose tested, and records handed over.
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Questions people ask
What is unitised curtain walling?
A curtain wall made of complete panels, framed and glazed in a factory, then lifted onto the building and hooked onto brackets at each floor. Neighbouring panels interlock to form the joints.
How much does unitised curtain walling cost?
A typical proprietary unitised system costs £1,400 to £1,600 per m² supplied and fitted, before VAT, access, design and testing. Bespoke systems on landmark buildings can cost more. Try the curtain walling cost calculator to size an elevation.
Is unitised better than stick curtain walling?
Neither is better in every case. Unitised suits tall, repetitive buildings and fast programmes; stick suits low-rise work, refurbishments and irregular facades, and costs much less per m².
How long does a unitised package take?
Design, mock-up testing and factory set-up commonly take several months before installation starts. Once panels arrive, installation is quick, often a floor or more a week on a straightforward building.
Can a damaged unitised panel be replaced?
Glass can usually be replaced from inside or outside depending on the system, and a whole panel can be removed if the design allows it. Ask about replacement methods before choosing a system, because some need a crane or cradle.
Find a unitised curtain walling specialist
Location first, then the package, then your contact details. Each step is short.
We are an introduction service, not a curtain walling contractor. We look for one that covers the project and name them to you first; nothing is passed on until you agree.
Thanks, we have your enquiry.
- We look for a curtain walling contractor that covers the project and handles this kind of package.
- When we find one, we email or call to tell you who they are. Your details reach that firm only if you say yes.
- They review the drawings or the building and price the work. No marketing from us.