Wide Windows and Patio Doors: Why Louvres Still Beat One Big Fabric Panel
Vertical blinds have an image problem. They are associated with 1990s offices and rented flats, and a generation of interiors writing has treated them as the thing you replace.
That is a shame, because on the specific window most houses now have, a wide rear opening or a patio door, they still do something no other format manages.
The problem with a wide single panel
Put a roller blind across a three metre opening and you have a single sheet of fabric on one tube, and several consequences follow.
The tube has to be thick enough not to deflect across that span, so the roll is bulky at the top. The fabric is heavy, so operating it is a two-handed job. And crucially, the only adjustment available is how far down it comes. You cannot open half of it, and you cannot let light in at the top while keeping the bottom covered.
On a door, there is a further problem. A roller blind across a patio door has to be raised entirely to get through the door, which in practice means it stays up.
What louvres do differently
A vertical blind divides the opening into a series of narrow panels that do two independent things: they rotate, and they slide.
Rotation lets you angle daylight without blocking it, which on a west-facing opening in the evening is the difference between a usable room and a closed one. Sliding lets you stack the whole blind to one side, so you can walk through a door without touching the rest of it.
That combination is why 1 Click Blinds vertical blinds remain the sensible answer on wide glazing, and why the format persists in commercial buildings where somebody has had to think about it properly rather than aesthetically.
There is also a practical point about scale. Because the blind is made of separate slats, the width of the window stops mattering. A five metre run is the same product as a two metre run with more slats, and a damaged section is a slat rather than a whole blind.
Where they genuinely fall short
Two places, and both are real.
They do not do darkness. There are gaps between slats by design, and even closed, light comes through the overlaps. In a bedroom that is disqualifying, and a blackout blind fitted inside the reveal is the correct specification instead.
And they look wrong on a small window. A narrow opening with four slats reads as an office, and this is where the format’s reputation comes from. The rule of thumb is that if the window is not appreciably wider than it is tall, choose something else.
Choosing the slat width
More consequential than the fabric. Wider slats mean fewer of them, a cleaner look and a bigger stack when open. Narrower slats give you finer control of the light and a busier appearance.
On a very wide opening, wider slats generally read better, because a large number of narrow panels starts to look like a screen. On a medium opening the narrower width gives more useful adjustment. Whichever you choose, make a note of it, because it is the measurement you need when a slat gets damaged and new louvres for the headrail have to match the ones already on the rail.
Fitting notes for a door
Two things worth getting right at the order stage.
Decide which side the blind stacks to, and make it the side away from the door handle. This sounds obvious and is the most common regret.
And set the drop so the slats finish clear of the floor rather than brushing it. Slats that drag pick up dirt along the bottom edge and eventually deform, and on a door threshold they catch every time somebody goes out.
Get the stack side and the clearance right and a vertical blind on a patio door will be the least troublesome window treatment in the house. Get them wrong and it will annoy you daily.