Cortizo Doors Explained: Cor Vision Sliding, Bi-Folds and Where Each One Works

Who Cortizo Are, and Why We Use Them

Cortizo is a Spanish aluminium systems manufacturer, and they are one of the systems houses we specify most often for sliding and folding doors. They extrude their own aluminium, which matters more than it sounds: it means the profiles, the thermal breaks and the hardware are designed as one system rather than assembled from whatever was available.

For a UK client the practical appeal is sightlines. Cortizo's minimal-frame sliding range gives you far more glass and far less aluminium than a conventional patio door, without moving into the price bracket of a fully bespoke structural glazing system. It sits in a genuinely useful middle ground.

We recently completed a custom Cortizo door and balustrade installation in Lancashire, which is a good example of where the system earns its place — large openings, a lot of glass, and a client who wanted the frames to disappear.

Cor Vision: The Minimal-Frame Sliding System

Cor Vision is Cortizo's minimalist sliding door. The defining feature is the interlock — the vertical line you see where two sliding panels overlap. On a standard patio door that interlock is chunky and sits right in your eyeline. On Cor Vision it is reduced to a slim vertical line, so what you notice is the view rather than the door.

Where it works particularly well:

• Rear elevations opening onto a garden, where you want the whole wall to read as glass
• Properties with a view worth framing — coastal, estuary or open countryside
• Contemporary extensions where a heavier frame would look out of place
• Openings too large for a bi-fold to handle elegantly

The trade-off with any sliding system is that you never get the full opening. A two-panel slider opens to roughly half the aperture, because one panel has to slide behind the other. That is the fundamental difference from a bi-fold, and it is the thing worth being clear about before you choose.

Cortizo Bi-Folds: When Folding Still Wins

Bi-fold doors have been slightly out of fashion in high-end work, largely because sliding systems have got so much slimmer. But there are situations where folding is still the right answer.

Choose a bi-fold when:

• You genuinely want the whole opening clear — for entertaining, or to connect a kitchen to a terrace completely
• The opening is moderate in width, where a bi-fold's stacked panels are not unwieldy
• You want the flexibility of a traffic door, so one leaf opens conventionally for everyday use

Choose a slider when:

• The view matters more than the opening — most of the year, the doors are shut and you are looking through them
• Panels are large, where fewer and bigger reads better than many and narrower
• You want a cleaner line when closed, with no stacked panels sitting in the reveal

Our honest view: for most UK homes the doors are closed far more often than they are open, so the closed appearance should carry more weight in the decision than it usually does.

Thresholds, Thermal Performance and Getting It Right

Two details make more difference to how a Cortizo installation feels than the choice of system itself.

The threshold

A flush threshold — where the internal floor runs out to the external paving with no step — is what makes a rear elevation feel genuinely open. It is entirely achievable, but it has to be designed in early, because it affects the floor build-up, the drainage and the weathering detail. Retrofitting a flush threshold to a slab that was not planned for it is expensive and sometimes not possible.

Thermal performance

Aluminium conducts heat, so the polyamide thermal break inside the profile is doing the real work. A well-specified Cortizo door with the right glazing unit performs perfectly well in a UK winter. A cheap aluminium door with a minimal thermal break does not, and you feel it as cold radiating off the frame even when the glass is fine.

The other variable is the glass itself. Solar control coatings, argon fill and warm-edge spacers all matter, and on a large south or west-facing elevation the coating specification does genuinely useful work.

We supply and install Cortizo systems across the North West and beyond, and we measure and fit every installation ourselves. If you are weighing up sliding against folding for a project, send us the drawings or a photo of the opening and we will give you a straight answer about which suits it — and a realistic budget.