Our approach

Three commitments carry every GMT Design project. They don’t follow one another: they apply in parallel, from the first conversation to handover.

What’s promised is what’s delivered

A specification is not a suggestion. Profile thicknesses, inertia values, specified brands, AEV ratings: every line is checked before pricing, then cross-checked before manufacture. Our proposal lists each reference against the specification, so you compare line by line, with no grey areas. No specification document? We start from your needs and give you the same level of detail.

Line-by-line C.P.S. verification
Justified AEV ratings
Supplier data sheets attached to the quote

Built for wind, salt and humidity

Tangier sets demands few cities know: the Chergui, salinity, permanent humidity. We treat every profile against marine corrosion (Qualicoat Seaside), we calculate the reinforcements for the wind zone (Zone 3), and we only use A4 stainless fixings: the marine grade, not the standard grade.

Qualicoat Seaside — marine anti-corrosion
Zone 3 calculated reinforcements
100% A4 stainless fixings

A finish you can see, and that lasts

The difference between a correct installation and an industrial-grade finish shows at 30 centimetres. Mitre joints assembled in the workshop, vulcanised EPDM seals — more durable than silicone — and site protection kept in place until handover. The last look before the keys change hands is ours.

Workshop mitre joints
Vulcanised EPDM seals
Protection until handover

The jargon, in plain words

Some technical terms come up on our site. Here they are explained in one sentence: to understand your quote, or to check what we are proposing.

C.P.S. (Cahier des Prescriptions Spéciales — tender specification document): The document, written by the architect or the client, that describes precisely what must be supplied and installed: materials, performance, standards. If you’re a homeowner, you generally don’t need one.
Qualicoat Seaside: A quality label for the powder coating (paint baked on in an oven) of aluminium exposed to marine air. It protects the metal from corrosion caused by salt.
Zone 3 (wind resistance): A wind-exposure class used to size profiles and reinforcements. The more exposed the zone, the more the joinery must be reinforced.
A4 stainless steel (Inox A4): Marine-grade stainless steel, which resists salt where standard stainless (A2) eventually pits. It is the grade to choose by the sea.
Vulcanised EPDM: A synthetic rubber used for sealing gaskets. It stays flexible in sun and cold; we prefer it to silicone, which ages less well.
AEV rating: Three performance measures for a window (A-E-V, from the French Air, Eau, Vent): air permeability, water tightness and wind resistance. The higher the rating, the better the window closes and withstands the weather.
Inertia (of a profile): The stiffness of the profile against bending. The higher it is, the better a large opening holds without deforming.
Thermal break: An insulating strip placed between the two faces of the aluminium profile, so that cold and heat don’t pass through the metal.
Uw (W/m²K): A measure of the heat loss of a whole window: the lower the figure, the better it insulates. 1.10 is a very strong value for aluminium joinery.
dB (sound reduction): The amount of outside noise the window stops. A 10 dB drop sounds, to the ear, like half the loudness: the higher the figure, the quieter it is.
VEC / VEA: Two glass facade techniques: bonded exterior glazing (VEC), with no visible fixings, and mechanically attached exterior glazing (VEA), held in place by profiles.
Curtain wall: A lightweight facade hung from the building’s structure, where glass and aluminium replace the wall.
Stadip Silence: An acoustic laminated glass: two panes bonded around a film that absorbs noise.
SP10: A reference for anti-burglary laminated glazing, much harder to break than ordinary glass.
Snagging: The end-of-works stage where the defects noted at handover are corrected.
Chergui: The east wind that blows across Northern Morocco. In Tangier it adds to the salty air and the humidity.