Curtain Walling Company and Contractor for London and the UK

Curtain walling is the non-loadbearing glazed skin hung off the front of a building's structure, carrying its own weight and the wind load back to the floor slabs, and BDF Architectural is a curtain walling company and contractor that designs, manufactures and installs aluminium and steel curtain wall systems for commercial, mixed-use and high-rise buildings across London and the UK. We take curtain walling packages as a sub-contractor to main contractors, work with developers and architects from design stage, and supply thermally broken, fire rated and blast enhanced versions.

We work mainly on Schüco FWS 50, a 50 mm mullion and transom system with a highly insulated FWS 50.SI version and structurally glazed FWS 50 SG variants for flush, all-glass elevations, and on Jansen VISS where a steel façade is specified, including VISS Fire for fire-resistant elevations. Profiles are processed and fabricated in our 60,000 sq ft West Drayton facility, with production sequenced by elevation, floor or zone to follow the construction programme.

Curtain walling reaches site through two kinds of company. System companies such as Schüco and Jansen design and test the profiles, gaskets and fixings as a system and publish its tested performance. Fabricators and installers like BDF Architectural turn that system into the façade on the drawings: we process and machine the profiles, fabricate and assemble the frames in West Drayton, then install them on site. When a main contractor looks for curtain walling manufacturers or suppliers, this second role is usually the one the package needs, and because fabrication and installation sit in one company, the curtain walling supplier and the sub-contractor on site are the same team, answerable for the same tolerances, programme and finished wall.

Most curtain walling is either stick or unitised. A stick system is assembled on site from mullions and transoms fixed to the slab edges, then glazed and sealed, which suits low- and mid-rise buildings, irregular elevations and sites where crane time is limited. A unitised system arrives as factory-assembled, glazed panels that are lifted into place floor by floor; it usually costs more to engineer and make, but it closes the building in faster with less work at height, which is why it is used on high-rise and time-critical buildings.

The glass is held in one of two ways. Capped systems clamp it with a pressure plate and a visible cover cap, giving a crisp grid of lines on the outside. Structurally glazed (SG) systems bond the glass to the frame with structural silicone, so the elevation reads as an almost continuous plane of glass. The two can be combined on one façade, for example capped mullions with silicone-jointed transoms to emphasise the vertical lines.

Insulated curtain walling uses thermally broken profiles, with an insulating break between the inner and outer parts of each mullion and transom, together with insulating glass units and insulated spandrel panels where the wall is opaque. The highly insulated FWS 50.SI is used where the thermal target is demanding. Overall performance depends on the glass, the proportion of frame to glass and the spandrel build-up, so thermal values are calculated for the actual façade rather than taken from a brochure figure.

Fire runs through every façade package. The gap between the slab edge and the curtain wall has to be fire stopped so fire and smoke cannot pass from floor to floor behind the glass, and responsibility for that line is agreed at design stage. Spandrel panels, insulation and other materials in the wall are specified against Approved Document B and the fire strategy, including the restrictions on combustible materials in the external walls of relevant buildings with a storey 18 metres or more above ground. Where the façade itself has to resist fire, we supply fire rated curtain walling such as Jansen VISS Fire, classified to the period the fire strategy sets.

Curtain walling is a construction product under BS EN 13830, which sets out how it is classified for air permeability, watertightness, resistance to wind load and other properties, each tested to its own method. The specification sets the classes needed for the project, and we confirm them at technical review against the system's tested data for the configuration and sizes on the drawings. Where the specification calls for site testing, typically a water test on sample areas once they are installed, it is planned into the programme with the main contractor.

As a curtain walling sub-contractor, our package normally runs from technical review and design development, with calculations for the framing and brackets, through fabrication drawings and samples for approval, to fabrication in West Drayton, sequenced delivery, installation, inspection and handover records. Doors, opening vents, brise soleil and the junctions with rainscreen cladding, roofs and ground-floor details can all be taken in the same package, so one team is responsible for the interfaces where most façade leaks start.

Recent curtain walling packages include a mixed-use development on Pentonville Road, Islington (2024), and an office building on Prescot Street, Whitechapel (2025), where we installed the curtain walling together with a full aluminium commercial door suite. Performance depends on the configuration, glass and tested scope, and is confirmed for each project at technical review against BS EN 13830 and the specification.

Programme is usually governed by design approval and material lead times more than by installation. Glass, especially large, coated or laminated units, and powder coating to a special colour often sit on the critical path, so early drawings, a settled glass specification and prompt approval of samples make the biggest difference to the start date on site.

To price a curtain walling package, send elevations and sections, the performance specification including thermal and acoustic targets, the fire strategy, structural and slab-edge information, interfaces with other packages, access and logistics constraints, and programme dates.