Aluminium glazing for architects — manufacturer-led from specification to installation
Direct Trade Windows is an in-house aluminium manufacturer in Slough, Berkshire. We work with practising architects across London, Kensington, Cobham, Richmond and the Home Counties — from RIBA Stage 3 specification through to site installation. Our in-house design team translates drawings into manufacturable specifications; our Slough workshop fabricates every frame on Fom Industrie equipment under one roof.
Home / Aluminium Glazing for Architects | London & Berkshire
Pre-qualified for main-contractor and public-sector frameworksConstructionline Gold Member · 25+ years in-house aluminium manufacturing · 3 system houses · CE-marked, IFT Rosenheim tested · In-house design team
Why architects specify Direct Trade Windows
We’re not a specifier-fabricator handover business. Our in-house design team works directly with practising architects from RIBA Stage 3 onwards. Drawings, schedules, U-value evidence, frame-depth detail, conservation precedent — handled from the workshop that will also fabricate the frame. Single point of accountability from specification through delivery.
No outsourcing of design. No outsourcing of fabrication. The drawing your design team marks up is the drawing our cutting team works from.
Specification across aluminium budgets
We don’t have a default range — we specify the best fit for the project. Cortizo, Smart Systems, and Aluprof are all fabricated in-house at our Slough workshop. System choice depends on the budget envelope, sightline requirement, thermal target, and the specifics of the elevation.
Cortizo (premium tier) — Cor 70 and Cor 80 (the higher-thermal variant) for windows, COR Vision / 4600 / 4700 for slimline sliding doors, Cor bifold for bi-folding doors (slimmest sightlines, up to 3 m heights), Millennium Plus for pivot entrance doors.
Smart Systems (full range fabricated in-house) — Visofold 1000 and 6000 for bifolding doors, Visoglide for sliding doors, Alitherm Heritage for steel-look heritage replacements, VS600 for vertical sliding sash windows.
Aluprof (specialist) — MB-86 for fire-rated applications and pivot entrance specifications where Cortizo Millennium isn’t the right fit.
We’re trained and tooled on all three system houses. We routinely cross-specify between them — recommending the optimal system within the budget rather than pushing the most expensive.
From specification to install
Specification stage — Drawings, schedules, and queries from architects are reviewed by our in-house design team. U-value evidence, frame depth, thermal break details, and conservation-area precedent are provided as standard.
Fabrication stage — Every frame cut, drained, crimped, and assembled in our Slough workshop on Fom Industrie equipment. Polyester powder-coating in-house to RAL or BS standard. QA at each station, not just final inspection.
Install stage — Direct fitting teams (no third-party installers). One project manager from order to handover. Snagging within agreed terms.
Projects from £4,000+VAT.
Recent architect-led projects
Little Acre, Buckinghamshire — Multi-system installation across a 600+ sqm residence. Cortizo COR Vision slimline sliding doors at the rear elevation. Cor 70 Hidden Sash windows on the street-facing aesthetic. Aluprof MB-86 pivot entrance door. Alitherm Heritage steel-look windows in the orangery. Three system families, one fabrication source, one specification team. View case study →
Frequently asked questions
How early should we bring DTW into a specification?
RIBA Stage 2–3 onwards. Earlier means more time to integrate U-value targets and system-specific tolerances into the architectural drawings.
Do you provide technical drawings for the design team?
Yes — typical jamb, head, cill, and corner sections in PDF or DWG. Available on request at specification stage.
Can you specify across budget tiers within aluminium?
Yes. We routinely cross-specify Cortizo against Smart Systems against Aluprof depending on the project’s budget envelope. We recommend the optimal system within the budget rather than pushing the most expensive.
Are you Constructionline accredited?
Yes — Gold Member, the top tier. Pre-qualified for main-contractor and public-sector framework agreements. Documentation provided on request.
Which sliding-door systems do you fabricate?
Cortizo COR Vision, 4600, and 4700 and Smart Systems Visoglide — system choice depends on the project. Both fabricated in-house at our Slough workshop in Berkshire.
Which bifolding-door systems do you fabricate?
Cortizo Cor bifold (slim sightlines, capacity to 3 m heights) and Smart Systems Visofold 1000 and 6000 — system choice depends on the project. All fabricated in-house in Slough.
What’s your minimum project value?
£4,000+VAT.
Where do you install?
London and the Home Counties — Kensington, Slough, Watford, Beaconsfield, Guildford, Oxford, Ascot, Reading, Brentwood, Cobham, and Richmond. Projects outside this radius are case-by-case.
Working on a specification? We can help with system selection, technical drawings, and pricing.
At Direct Trade Windows, our commitment to excellence is reflected in our exceptional customer satisfaction.
We take great pride in our impressive 4.9 rating on Google, a testament to the unparalleled quality and service we offer.