Blindspace Concealed Blinds: The Complete Guide for Architects, Builders and Homeowners

Windows keep getting bigger. Glazed panels are more expansive, there are fewer transoms and mullions, and ceiling to floor glass in new builds is now routine. It looks superb, and there’s usually a view worth having.

Then the shading question arrives, and with it the realisation that any blind we fit will be visible even when it’s fully retracted. If it’s motorised, the cabling may be visible too.

Concealment solves that. It also changes the entire order in which decisions get made, and that is the part people find hardest.

The single most important thing to understand

The whole process runs backwards. Every decision we’d normally make at the end of a build has to be made before it starts.

On a conventional job we arrive once the house is finished. We measure the windows, we ask what you want the shading to do room by room, and we advise on the product that suits. Nothing is committed until you can stand in the room and see it.

Concealment removes that option entirely. The cavity is part of the building, so it has to be on the architect’s drawings, which means it has to be settled while the house is still being designed.

Conventional shading	Concealed shading
House is finished	House is still being designed
We measure the actual windows	We work from drawings
We ask what you want the shading to do	You have to have decided already
We advise on the right product	The product has to be chosen up front
The blind is made to suit the window	The building is built to suit the blind

Why the blind has to be chosen first

Each step depends entirely on the one before it, and the chain only runs in one direction:

What you want the shading to do → which blind → which Blindspace box → what size and type of cavity → what the architect draws

We can’t tell your architect what cavity to design until we know which box. We can’t specify the box until we know the blind. And we can’t recommend the blind until you’ve told us what that window has to achieve.

So the homeowner needs to know exactly which blind is going in, at a point when the house may be no more than drawings. That’s a difficult ask. You’re being asked to choose shading for rooms you can’t stand in, sometimes a year or more before you move in. It’s the part of the process that goes wrong most often.

There’s no way round it, but there is a way through it, and it starts with a list rather than a product.

Start with what you want the shading to do

Not which box, and not which blind. What each window needs to achieve, which usually varies room by room:

• Privacy
• Room darkening
• Glare control
• Controlling heat loss in winter
• Preventing heat gain in summer
• Thermal insulation
• Sound insulation and noise reduction
• Visibility out when the blind is down
• Automatic operation
• Unattended operation
• Linked to a home automation system
• Inward opening window options
• Sliding patio door options

Work through that list with your architect early. It’s the conversation that unlocks every other decision, and it costs nothing to have at the drawing stage.

Who does what

Blindspace is a construction product, not a blind accessory, and it has to appear on the drawings like any other building element.

• The architect incorporates the box into the drawings and specifies it by name, including the size and the flange variant. That specification can’t be written until the blind is known.
• The builder forms the cavity to that specification and installs the box while the ceiling is still open.
• Either the architect or the builder buys the boxes from us. We supply them cut to a finished length, or in lengths of up to 4 metres for cutting on site by whoever is fitting them.

We provide Blindspace on a supply-only basis, to a specification created by the architect or builder. We can’t offer measuring or installation services for this product, and we can’t take responsibility for a cavity formed to someone else’s specification.

What we can do, and what we’d rather do, is tell the architect which box each window needs before the drawing is finished.

The cavity size, and the rule behind it

The rule is straightforward: the recess is the box size plus a 3mm tolerance for ease of installation. What changes from job to job is the box, and the box is driven by the blind.

Box	Recess needed	Typically suits
S100x100	103 x 103mm	The smallest standard box. Roller blinds up to around 2.4m wide
S110x130	113 x 133mm	Cellular blinds. Our Blindspace drawing for a 32mm Duette specifies this box, for blinds up to 2200mm wide and 3000mm drop
S130x130	133 x 133mm	Wider blinds, up to around 3.5m
C Series	Made to suit	Custom sizes for large, dual or shaped blinds. Deeper boxes such as 130x180 and 130x200 are common

Whatever shading system is finally chosen, it’s unlikely the recess will be less than 110mm front to back and 130mm deep. Roller blinds need a considerably larger box than cellular blinds, because the tube diameter grows with the width.

Don’t let anyone form a cavity before the blind and the box are both confirmed. A cavity built to the wrong figure is a structural correction, not a decorating one.

Cellular or roller?

Both work, and the choice has consequences for the building rather than just the blind.

Cellular blinds hold a slim profile as they get wider, so the box size stays predictable. Roller blinds need a progressively larger tube as the width grows, which pushes you into a bigger box and a bigger cavity. Where several rollers sit side by side you’ll also see a gap between the vertical fabric edges, which can be more noticeable on taller windows.

If you’re expecting the seamless look that concealment promises, that’s worth understanding at the design stage rather than after the plasterboard is up.

Windows that make concealment harder

Inward-opening windows, and tilt-and-turn units in particular, can be awkward. The sash opens into the room and can collide with the blind. Outward-opening windows, whether casement, top-hung or sliding sash, are far more straightforward.

If tilt-and-turn windows are in the design alongside concealed blinds, raise it early. It’s a cheap conversation now and an expensive one later.

How it’s supplied

• Cut to a finished length by the manufacturer and fitted with end caps, or supplied in lengths of up to 4 metres to be cut on site. Four metres is the maximum that can be carried to site.
• Stock boxes are held at 6 metres, and the S Series is also sold in 3 metre lengths, but a 6 metre length is collection only from the UK distributor.
• Longer runs are made by joining boxes with splice pins and splice plates, which keep the boxes and covers aligned.
• Standard colour is white. Powder coating to any RAL is available as a chargeable option, with a one-off set-up charge per colour.
• Boxes are shipped from the manufacturer in Sweden, so shipping is additional.

Flange options, and what we recommend

There are four variants, and the variant has to be specified at the time of ordering:

Variant	What it is
Regular (R)	Skim coat flanges on both edges, plastered over
Idle Corner (I)	One flange, on the idle corner side
Hinge Corner (H)	One flange, on the hinge corner side
No Flange (N)	No flanges at all. This is what we recommend

With the no-flange option the box is fixed upwards into a timber backing set above the cavity. Blindspace’s own guidance is that there should be a stud or other solid structure above the box, so the timber is needed either way. It’s a cleaner, more predictable fixing, and it doesn’t depend on the plasterer working neatly around a perforated flange.

This has to be settled at build stage. Changing the mounting approach after plastering is difficult and expensive.

What the box actually buys you

The box is a liner. The part that earns its keep is the cover flap, fitted once the blind is in.

• Without the box: an open slot in the ceiling of around 110mm.
• With the box and flap: that closes down to roughly 45mm to 50mm, depending on the blind.

So the gain is a neater, narrower slot, and on a carefully designed interior that can be exactly the right call. It just isn’t magic, and it isn’t cheap.

The point architects most often miss

Think about the vertical plane the blind travels through, not just the cavity. The centre line of the blind, the full path of the fabric and the bottom bar all need to be considered before anything is ordered and built in.

We had a project where the architect had designed a good ceiling cavity, then overlooked the large handles going onto the sliding patio doors. The blind’s travel would have fouled on the handles. The ceiling cavity had to be ripped out and started again.

Blindspace put the same warning on their own drawings: make sure there is space for window and door handles. Check ironmongery, door reveals, window boards and radiator tops against the line of travel before the ceiling closes up.

Future-proofing: fit the boxes now, decide the blinds later

The covers close the box completely, so a box can be built in and left empty. Your build team installs the boxes and runs the cabling during construction, and the blinds go in whenever you’re ready, with no structural work at that point.

That’s genuinely useful on phased builds, on budget-conscious projects, and where the design is still moving. If the blinds are going to be motorised, the cabling has to be run at first fix, before the walls are closed up, so it needs to be on your electrician’s list early.

Does it need concealing at all?

This is worth asking properly, because the answer is often no.

Duette in particular is one of the tightest, neatest installations there is. The stack is small, the headrail is slim, and fitted properly it already looks deliberate rather than added on. We’ve had clients who set out determined to hide the blinds and were perfectly happy without a box.

A worked example, on Skye. The client wanted a cavity. By the time we were involved the house was too far on: the architect had already designed steel beams above the window frames, so there was no room to form one. We fitted the Duette blinds conventionally instead, and the clients were delighted with the result. That job is in our Duette gallery.

The simpler alternative

If you do want the blinds out of sight, there’s a route we’ve been specifying for clients for many years: a plain cavity formed above the window reveal. No proprietary box and no flap, just a well-made recess. It costs a fraction of the price and it does the main job.

If your builder can form the cavity anyway, it’s worth asking what the box is adding beyond the flap.

Cost

Blindspace works out from around £300 per linear metre or part thereof, excluding VAT, plus shipping. Set-up charges apply where boxes are powder coated to a specific colour.

That’s a considerable sum for what is, in essence, a lined cavity with a hinged flap, and it’s often being spent to conceal a blind that doesn’t need concealing. We’d rather say that at the design stage than after the plasterboard is up.

Where to go from here

Bring us in while the house is still on the drawing board, not once the structure is up. By then the answer is usually that the cavity can’t be formed. The order that works is:

1. Settle what the shading needs to do, window by window, with your architect.
2. Choose the blind on that basis, and let the blind determine the box.
3. Check the cavity is achievable, with no steel or structure in the way.
4. Check the blind’s line of travel against every handle and fitting on the glazing.
5. Only then choose between a plain formed cavity and a Blindspace box.
6. If the blinds are motorised, get the cabling planned in at first fix.

The best next step is a conversation

Concealment decisions are hard to settle by email, because every answer depends on the one before it. Fifteen minutes on a video call with your drawings on screen will get you further than a fortnight of messages.

David Browne, our Project Director, takes these calls himself. He’ll walk you through where you are with the build, what each window needs to do, whether concealment is the right call, and if it is, which box and which cavity your architect should be drawing.

Schedule a video call with David Browne

We supply Blindspace across Scotland and carry a full range of motorised blinds suitable for fitting into Blindspace boxes. Our Design Studios in Dundee and Edinburgh have full size displays and are open by appointment.

Please note: we only provide Blindspace concealment products for blinds. We don’t supply curtain tracks or concealment products for curtain tracks.

Blindspace® is a registered trademark of Blindspace AB. Duette® is a registered trademark of Hunter Douglas. Blindspace sample CAD drawings are for representational purposes only and should not be incorporated directly into your designs. Dimensions quoted are for guidance; the specification for any individual project must be confirmed against the actual blind selected.