Fixed, curtain wall & special shapes
Picture windows, ribbon glass, and bespoke geometries are where the grid meets structure. This page covers the METABUILD approach: setting-out, wind transfer, mullion splices, and how we keep water on the right side of the line. The numbers for stick vs unitised, glass thickness, and structural silicone bite live in the supplier test evidence and in the issued product schedule for your order—treat the web as narrative, the submittal pack as the contract set.
A fixed field can be a simple IGU in a lineal frame, a four-side structural silicone zone in a mullion grid, or a trapezoid/gable with compound angles. Each needs a unique template, verified template survey, and load path to the supporting steel or concrete—never “as drawn” on day one of install without sign-off of the T&C chain.
System families
Stick / ladder curtain wall (site assembled)
Mullions and transoms delivered in lengths, capped on site, pressure-plate, or structurally silicone-glazed. Suited to phased logistics and to interfaces that change floor by floor. Tolerances in setting-out and bracketry must match the mullion splice detail and the movement joint strategy.
Unitised façades (factory pre-glazed)
Lighter on-site time in the critical path, larger crane pick weights, and hoisting sequence integrated with the main contractor. Inter-unit joints carry movement, water management, and air tightness; smoke seals and spandrel insulation follow the fire-engineer’s line.
Framed picture fixed lights
Within a window / door system family, fixed lights use the same beads and drainage as the operables, simplifying interior lines and spares. Often the cost-optimal way to get large unbroken fields next to a door run.
Special geometry
Common patterns include:
- Raked or curved heads, faceted or true radius, with adjustable brackets for twist.
- Trapezoid or parallelogram units where the horizontal is not square to the vertical.
- Overhead sloped glazing, including snow load and condensate run-off to guttered zones.
- Spandrel panels—opaque, insulated, and sometimes fritted—with cavity barriers placed per the tested detail.
Each is templated, numbered, and sequenced. Glass cutting lists and fabrication tolerances are cross-checked to the three-dimensional model before the order locks.
Structure & deflection
The façade engineer supplies support reactions, sway limits, and any net uplift at corners. We map bracket spacing to mullion depth and the glass line load. Where floor slabs deflect, we detail sliding connections or slotted holes at one end of a mullion run, always keeping drainage continuous and unpinched.
Weathertightness & condensate
The rainscreen line is the primary shield; the inner line is the air line. Cavity baffles, pressure equalisation, and cap terminations (with end dams) stop cross-jets from short-circuiting the drainage path. In cold weather, the warm line must stay behind the insulation; otherwise you chase interstitial condensate. We provide isotherm sketches when asked for a given U-value make-up.
Glass for fixed fields
Thickness, coating position, and edge treatment follow structural glass calculation (including barrier loads), acoustic targets, and the risk of nickel sulphide inclusions in heat-soaked or non-HS toughened panes. Oversized units may require jumbo laminates, heat-strengthened plies, or a split mullion—cost and programme impacts are flagged at tender, not in the fit-out.
Typical data points (illustrative)
| Grid / movement | Stated mullion span + building movement; verify splice positions vs structural grid |
|---|---|
| U-value / solar | From spandrel and vision package; solar gain checked against Part L / overheat doc |
| Acoustics | Field measured STC or indoor ambient vs traffic map; upgrade path in glazing pack |
| Access / cleaning | BMU loads, cradles, or internal access hatches; glass replacement strategy for upper floors |
| The signed-off product schedule is the master list of tested assemblies and spandrel build-ups for your project’s brand. | |
What we need to quote
- LOD / elevations with grid dimensions and FFL / SSL datums.
- Primary structure drawings or reactions if available.
- Fire strategy extracts for zones touching our line.
- Finishes schedule for caps, spandrel infill, and colour references.
Start a special-glazing package
We will respond with a system proposal, performance assumption list, and drawing checklist.
Contact METABUILD