Roman Blinds Outside Recess: Measuring & Fitting Guide
Yes, Roman blinds can be fitted outside the window recess. This mounting method involves securing the blind's headrail directly to the wall or architrave above and around the window frame, rather than inside the opening itself.
Key Points
- Roman blinds can be fitted outside the recess by mounting to the wall or architrave, making them ideal for shallow window openings or those with obstructions.
- For accurate ordering, measure the total width including 5–10cm overlap on each side, and determine the drop from your mounting point to below the windowsill.
- Outside recess fitting offers superior blackout performance, reduces light gaps around edges, and creates the illusion of larger windows.
- Choose outside recess mounting if your window depth is less than 7cm or you need maximum light blocking for bedrooms and nurseries.
Can You Fit Roman Blinds Outside the Recess?
Outside mounting works particularly well when your window recess is shallow—common in period properties where the depth may not accommodate the blind's mechanism. It also solves problems with protruding window handles or inward-opening casements that would otherwise obstruct the fabric.
A practical benefit is reducing the stack height problem. When a Roman blind is raised, the fabric folds into a concertina shape at the top. On smaller windows fitted inside the recess, this stack can block 20 to 30 per cent of the glass. Mounting outside allows the folded fabric to sit above the glazing entirely, letting more daylight through.
For proper light exclusion—particularly useful in bedrooms—aim for a minimum 50mm overlap on each side of the window opening. This reduces gaps where light might seep around the edges.
What Does Outside Recess Mean?
Outside recess is a mounting method where a Roman blind attaches to the wall or architrave surrounding your window rather than sitting inside the opening. This approach places the headrail and fabric outside the window reveal, allowing the blind to hang flat against the wall surface.
When you choose an outside recess fit, the blind overlaps the wall on each side of the window. This overlap creates several practical benefits. Light leakage around the edges drops considerably, making it a popular option for bedrooms. The fabric stack—the folded material when the blind is raised—sits clear of the glass, so you retain your full view.
Outside mounting suits windows with shallow reveals, protruding handles, or tilt-and-turn mechanisms. It also works well for decorative sills you want to keep clear of brackets.
Why Fit Roman Blinds Outside the Recess?
Fitting Roman blinds outside the recess means mounting them on the wall or architrave surrounding the window rather than inside the frame. This approach solves several practical problems and often looks better too.
The main reason to choose outside mounting is shallow window depth. Roman blinds need at least 7.5 cm of recess depth to fit properly, and many UK homes—especially those with timber frames or period features—simply lack that space. Mounting outside sidesteps the issue entirely.
Roman blinds also create a thick fabric stack when raised. With an inside fit, that bundle sits at the top of the glass and blocks light. Outside mounting lets the stack rest against the wall above the window, keeping the entire pane clear and maximising daylight.
There are several additional benefits:
- Better light blocking – the blind overlaps the frame edges, reducing gaps where light can creep through.
- Larger appearance – extending the blind beyond the recess makes windows look taller and wider.
- Protection for woodwork – fixings go into the surrounding wall instead of delicate window frames.
- Hides imperfections – uneven reveals, exposed hardware or mismatched architraves disappear behind the fabric.
How to Measure for Outside Recess Roman Blinds
Outside-recess Roman blinds sit on the wall around your window rather than inside the opening. Measuring for this style is straightforward once you understand where to add extra fabric for overlap and stack-back.
Start with the width. Measure the full width of your window recess, then add 5–10 cm to each side. This overlap blocks light gaps and gives the blind a fuller appearance. For a 100 cm recess, your finished blind width would be 110–120 cm.
Next, measure the drop. Decide where you want the headrail or batten positioned above the window—ideally 10–15 cm higher than the recess top. This extra height lets the folded fabric (the stack-back) sit above the glass when the blind is raised, keeping your view clear. Measure from that mounting point down to at least 5 cm below the windowsill.
Check for obstructions. Radiators, handles, dado rails or decorative architraves can get in the way. If anything protrudes, you may need spacer blocks or a deeper batten to hold the blind further from the wall. Allow at least 7.5 cm clearance from projecting mouldings.
Take three drop measurements—left, centre and right—and use the smallest figure if your sill is uneven. This prevents the fabric bunching at one corner.
Finally, confirm your mounting substrate. Plasterboard alone won't hold the weight; locate timber studs or window headers for secure fixing.
Inside vs Outside Recess: Key Differences
Inside recess and outside recess are the two main mounting positions for Roman blinds, each suited to different window types and room requirements.
An inside recess fit sits within the window frame, creating a clean, tailored appearance that suits modern interiors. The blind sits flush with the wall, reducing its visual footprint and keeping high-traffic areas clear of any protruding fabric. However, this option requires a minimum recess depth of around 50mm for the mechanism to sit properly. When raised, the concertina fold creates a fabric stack of roughly 20–30cm, which can block a noticeable portion of daylight on smaller windows.
An outside recess fit mounts on the wall above and around the frame. This approach works well for shallow recesses—common in period properties and timber frames—where an inside fit simply will not work. Outside mounts also suit windows with inward-opening casements or bulky handles that would obstruct an internal blind. By overlapping the wall, this position reduces the 'halo' of light leakage around the edges, making it a practical choice for bedrooms.
The trade-off is visual: outside mounts expose the blind's side profile, which may look less streamlined in minimalist spaces.
Blackout Roman Blinds and Outside Recess Fitting
Blackout roman blinds are window coverings with a light-blocking lining, and outside recess fitting is a mounting method that fixes the blind to the wall above and around the window frame. This combination offers the best approach for rooms where darkness matters—bedrooms, nurseries and home cinema spaces.
When you fit a blind inside the recess, light often creeps around the edges, creating a 'halo effect' that defeats the purpose of blackout fabric. An outside fit solves this by extending the blind beyond the window opening. Most fitters recommend an overlap of 10–15 cm on each side for proper light control.
There is another practical benefit. Roman blinds fold into a fabric stack when raised, and this stack can block 20–30 cm of the upper glass on an inside fit. With outside mounting, the stack sits above the frame, keeping the full window clear during daylight hours.
Outside fitting also suits properties with shallow window reveals or internal handles that would obstruct an inside mount. The trade-off is that the blind's side profile remains visible from certain angles.
Which Fitting Option Is Right for You?
The right fitting option depends on your window's depth and how you plan to use the room. Measure your recess first—if it is shallower than 7.5 cm, inside fitting is unlikely to work because the mounting hardware will not fit properly.
For a clean, built-in look, inside recess fitting suits deeper windows where the blind sits neatly within the frame. This works especially well in timber-framed houses, where you can mount brackets directly onto the wooden surround.
Outside recess fitting is often the better choice for Roman blinds. Because the folded fabric creates a bulky stack when raised, an inside fit can block 20–30 cm of glass at the top of your window, cutting daylight. Mounting outside lets the blind sit above the frame so more light enters when the blind is open.
Outside fitting also reduces light bleed around the edges, making it preferable for bedrooms where you want near-blackout conditions. Finally, consider practical details: radiators beneath the sill or plans to add a pelmet may influence which approach suits your space.
Frequently Asked Questions
How much overlap should Roman blinds have outside the recess?
For an outside recess fitting, you should add at least 50mm of overlap on each side of the window recess. This additional width helps block light gaps around the edges and creates a more polished, proportional appearance.
What is the minimum recess depth for Roman blinds?
Inside recess fittings require a minimum depth of 7.5cm to accommodate the headrail and fabric stack. If your window frame is shallower than this, an outside recess mount is the recommended alternative.
Do outside recess Roman blinds make windows look bigger?
Yes, mounting Roman blinds outside the recess can create the illusion of larger windows. By extending the blind beyond the window frame, you draw the eye outward and add visual height and width to the overall window area.
What is the halo effect with Roman blinds?
The halo effect refers to light leaking around the edges of a blind, which is common with inside recess fittings. An outside recess mount helps neutralise this issue by covering the full window surround, making it ideal for bedrooms and nurseries.
