How to Plan Curtain Pelmets & Ceiling Pockets: Depths, Stack Space and Power

Almost every motorised curtain problem we are called to fix in Hyderabad is not a curtain problem. It is a carpentry and ceiling problem that was locked in long before anyone chose a fabric: a pocket too shallow to hide the track, a recess that stops 300mm short of where the motor needs to sit, no power point within reach, or a cove light aimed straight into the slot that was supposed to conceal everything. This guide sets out the dimensions and the services to fix on the drawing, and it sits alongside the rest of our coverage of home automation in Hyderabad. If you have not yet sized the track itself, read it together with how to measure windows and choose tracks for motorised curtains — that article covers the track, this one covers the hole it disappears into.

Pelmet, pocket, valance: what you are actually building

The three words get used interchangeably on site, which causes real confusion when a carpenter, an electrician and a curtain installer are each acting on a different meaning. Worth separating them:

• A ceiling pocket (or curtain pocket) is a recess formed within the false ceiling itself — a slot running along the window, open at the bottom, with the track fixed to the soffit inside it. The fabric emerges from a clean dark gap and the ceiling reads as one continuous plane. This is the detail worth aiming for in any home where the false ceiling is being made new.
• A pelmet is a shallow box, usually plaster, ply or MDF, built below the ceiling line to hide the track from view, typically 120–200mm deep on the face. It is what you build when the slab is already exposed, when there is no false ceiling at that window, or when the ceiling drop cannot be increased.
• A valance is a decorative fabric or upholstered band across the top of the curtain. It is a soft-furnishing choice, not a construction one, and it makes access to a motor harder rather than easier.

For motorised curtains the pocket is the better detail almost every time, because it hides the motor as well as the track, and because it does not add a visible horizontal band that eats into a ceiling height Hyderabad apartments rarely have to spare. The trade-off is that it must be committed to at the false-ceiling stage — it is not something you add later without opening the ceiling.

The dimensions: depth, width and the two-track case

These are the numbers to write on the drawing. They are internal clear dimensions of the recess, not the outer size of the ceiling drop.

Depth: 150mm clear, and why 100mm is not enough

Plan for 150mm of clear internal depth from the finished ceiling plane up to the underside of the soffit inside the pocket. That figure covers three things stacked on top of each other: the track and its fixing brackets (roughly 30–50mm), the runners or carriers hanging below it, and the top hem of the fabric with its pleat heading. It also gives a hand and a screwdriver somewhere to go at installation and at service.

The pockets that get built when nobody specifies a number are usually 75mm or 100mm, and they fail in a predictable way: the track edge and the metal hooks are visible from a seated position across the room, which is exactly the sightline you actually live at. The other thing 150mm buys you is sightline tolerance. A person standing 3m back from a window looks slightly upward into a pocket; at 150mm the ceiling lip screens the hardware, at 100mm it does not.

Width: 120–150mm for one track, 200–250mm for two

A single track needs 120–150mm of clear width — enough for the track, the fabric hanging below it and a working gap of at least 30–40mm between the fabric and the pocket wall so the curtain never scrapes plaster on its way across.

Most homes should actually be planning two layers, which is the case worth designing for by default: 200–250mm of clear width, with the two tracks set 80–120mm apart. The sheer goes on the window side, the blackout on the room side. Below 80mm of separation the two fabrics touch as they pass, which both looks wrong and, over years, wears the sheer. Above about 120mm you are simply widening the ceiling drop for no benefit.

One more clearance that gets missed: keep at least 50mm between the window-side track and the glass or the reveal face, so the sheer hangs freely and does not press against the window when it is closed, and so a slightly out-of-plumb wall does not throw the whole run out.

A quick reference

• Single track, sheer or blackout only: 150mm deep × 120–150mm wide.
• Dual track, sheer + blackout: 150mm deep × 200–250mm wide, tracks 80–120mm apart.
• Dual track with a heavy lined drape: 150–180mm deep × 250mm wide — heavier headings sit taller.
• Pelmet (below-ceiling box) instead of a pocket: 150mm face depth minimum for one track, 180–200mm for two; the face must sit below the bottom of the runners, not level with them.
• Minimum clear gap, fabric to any surface: 30–40mm on each side.

Planning around the motor end

This is the single decision that separates a pocket that works from one that has to be reopened, and it is the part that genuinely differs between motorised and manual curtains.

A curtain motor is an inline cylinder, typically 40–60mm in diameter and 250–400mm long, that sits at one end of the track. It is heavier than the track and it needs power. Three consequences follow:

1. Choose the motor end at drawing stage. Put it at the end nearer a wall, a corner or a column — somewhere the extra length is naturally absorbed — and, wherever possible, at the end opposite the side you want the fabric to stack on, so the motor is not competing with the stack for the same 400mm of pocket.
2. The pocket must run past the window at that end. A recess that stops neatly at the reveal leaves nowhere for the motor. Continue the pocket at least 400mm beyond the last carrier at the motor end. In practice, running the pocket wall-to-wall is both simpler for the ceiling contractor and better looking, and we recommend it whenever the wall allows.
3. Fixing matters more than with a manual track. A motorised track carries a starting torque every time it runs, so brackets go into the soffit or a properly anchored frame at 600mm centres or closer, never into a gypsum board face alone. On a long run with a heavy blackout, tighten to 450–500mm centres.

Also leave the motor reachable. Motors are extremely reliable, but over a fifteen-year life something will need attention — a limit reset, a coupling, eventually a replacement. A pocket that is open along its full length at the bottom is inherently serviceable. A pelmet box that has been sealed and painted shut is not, and one that requires a joiner before an installer can even look at it turns a twenty-minute service call into a repair job.

Stack space, track extension and how far to run past the glass

Stack space is where curtains most often disappoint people, and it is a planning number rather than a fabric one.

“Stack” is the bundle of gathered fabric when the curtain is fully open. As a working figure, allow 12–18% of the total track length per side for a centre-opening pair. A 3,000mm track therefore parks roughly 350–500mm of fabric at each end. Use the lower end of the range for a light sheer at 2x fullness and the upper end for a lined blackout, which bunches fatter.

The implication is direct: the track should be longer than the window. Extend it 300–500mm past the reveal on each side so the stack lands on wall rather than on glass. If you size the track to the opening instead, then even fully open the curtain permanently covers 200–300mm of glass at each side — you lose daylight and view all day, and the room reads as though the curtains are never quite open. The pocket, of course, has to be built to that longer dimension, which is precisely why this is a ceiling decision rather than a curtain decision.

Two adjustments worth knowing:

• Where there is wall on only one side — a window into a corner, common in apartment bedrooms — use a single-sided draw and put the entire stack on the wall side. Trying to force a centre-opening pair in that situation guarantees half the stack sits over glass.
• For a very wide run, past about 4.5–5m, split into two tracks with a small overlap at the centre rather than one very long one. Two motors driving 2.5m each are quieter, quicker and easier to service than one dragging 5m of lined fabric, and in a scene they move together anyway.

The full measuring method, fullness ratios and track selection are covered in how to measure windows and choose tracks for motorised curtains, and the case for motorising at all is in motorised curtains and smart blinds in Hyderabad.

Coordinating with the cove, the AC grille and the ceiling drop

The curtain pocket does not exist in isolation. It runs along the same perimeter that everything else in a false ceiling wants to occupy, and the conflicts are predictable.

The cove: adjacent, never shared

A cove and a curtain pocket must be separate recesses with a plaster fin between them. Share one recess and two things go wrong at once: the cove light spills into the pocket and brightly lights the track, the carriers and the motor — the exact hardware the pocket exists to hide — and the curtain fabric hanging in front blocks the cove's own upward throw, so you lose the soft ceiling wash you paid for.

The clean detail is a 50–75mm plaster fin separating the two, with the cove on the room side and the curtain pocket behind it against the window. If you want the fabric lit deliberately — and a grazing wash down a good sheer is one of the better effects in a living room — add a separate low-output strip, roughly 300–500 lm/m at 2700K, on the room-side face of that fin, aimed down the fabric, on its own dimmable channel. Cove geometry itself is covered in how to plan cove lighting in a false ceiling, and channel grouping in how to plan dimmer channels and lighting loads.

The AC grille and the duct

In most Hyderabad apartments the ducted indoor unit sits in exactly the same perimeter zone the curtain pocket wants. Two rules: never let a supply grille discharge into or across the curtain pocket, because a jet of cold air onto a hanging sheer makes it billow permanently and the movement reads as a fault, and check the duct depth against your ceiling drop before promising a 150mm pocket. Where a duct crosses the window line, the honest answer is either to drop the ceiling further at that band or to move the pocket forward into the room by 100–150mm and accept a slightly deeper reveal.

The ceiling drop and the head height

A 150mm pocket needs the false ceiling to be at least that far below the slab at the window line, plus the thickness of the framing and board above it — call it 200mm of usable drop in total. Do this sum early. In an apartment with a 2.9m slab-to-floor height and a duct crossing the window, ceiling height at the perimeter is a genuinely scarce resource, and the pocket is competing with the duct, the cove and any recessed lighting for the same band. It is far better to know in the drawing that only 120mm is available and design a shallow pelmet properly than to discover it on site and improvise.

Finally, a finish detail: paint the inside of the pocket matte black or a very dark grey, not ceiling white. A white pocket interior catches every stray beam and turns the slot into a bright band that draws the eye to the hardware. Matte black makes it read as a clean shadow gap. This is the same instinct behind reading the ceiling as a designed surface rather than a leftover one — see how to read a reflected ceiling plan for home lighting.

Power, control cable and what to leave in the ceiling

Everything above is carpentry. This part is the electrician's, and it has to be on the same drawing.

1. A 5A switched point inside or immediately beside the pocket, at the motor end. One per motor. Not a point 2m away on the wall with a cable looping to it — that cable becomes permanently visible. Where a low-voltage motor is used, the driver still needs a mains point somewhere accessible.
2. A control cable back to the automation panel. Even where the motor will finally be controlled wirelessly, running a spare cable costs almost nothing at first-fix and preserves the option of a wired, deterministic connection. The general argument is in wired vs wireless home automation.
3. A keypad back-box on the correct wall. Curtains should be a labelled button beside the door and at the bedside — not an app you have to unlock. Decide the wall and the button engraving now; see how to plan keypad layouts and engraving.
4. An accessible junction, never a sealed one. Any joint in the pocket must remain reachable from below without cutting the ceiling.
5. A note of the motor end on the drawing itself. Write it down. On site, six weeks later, nobody remembers which end was agreed, and the ceiling contractor will centre the recess on the window because that is what looks right to them.

Two more specification points worth insisting on. Ask for the motor's noise figure and aim for under 35–38 dB in a bedroom — a pocket amplifies slightly, being a hard-surfaced box, so this matters more here than in an open pelmet. And confirm the motor has a manual override, so a gentle pull on the fabric or a physical release moves the curtain during a power cut. That behaviour, and the wider question of what still works when the power or the internet drops, is covered in do smart homes work during power cuts and internet outages.

The full list of provisions to leave across a whole home — not just at the windows — is in when to plan home automation during construction in Hyderabad.

If the ceiling is already done: honest retrofit options

Plenty of homes come to us finished. A ceiling pocket is then off the table, but three approaches work well and it is worth being clear about the trade-offs of each.

• A surface pelmet box below the ceiling. A plaster or MDF box, 150mm face depth for a single track and 180–200mm for two, fixed to the soffit and painted to match the ceiling. It is the closest visual result to a pocket. It costs ceiling height at the window and, if it stops short of the window's full width, the box itself becomes the visible element — so run it wall-to-wall where you can.
• A ceiling-mounted track, left honestly exposed. With a slim white or black anodised track and a wall-coloured motor tucked into a corner, this is far less objectionable than people expect, and it is the cheapest and most serviceable option. Choose a track profile you are happy to see, and align it deliberately — a track that is parallel to the ceiling line and centred reads as intentional; one that is 40mm off does not.
• Wall-mounted brackets above the window. Use this when there is no soffit worth fixing to. Mount the track 150–200mm above the window head so the fabric appears to fall from higher than it does and the window reads taller, and extend it the same 300–500mm past each side for the stack.

Retrofitting automation into a finished home is a whole discipline of its own; the broader version is in can you add home automation during renovation in Hyderabad.

How Pert delivers it — a designed solution, not a DIY kit

Pert is a solutions company: we design and install, we do not hand over a box of parts. On motorised curtains that means a site visit to measure openings, reveals, available wall for stacking and the actual ceiling drop at each window; a drawing that marks pocket depth, width, wall-to-wall extent, the motor end, the 5A point and the control cable route — issued to your ceiling contractor and electrician before the false ceiling is boarded; coordination with your interior designer on the pocket-versus-pelmet decision and its effect on ceiling height; professional installation of motorised curtain tracks and motors, with limits set and travel tuned on site; and integration into scenes on a wall keypad so Morning, Movie and Good Night move the curtains alongside the lighting and, where fitted, arm the security system. Worked scene examples are in how to design home automation scenes.

If you are comparing providers on whether they will actually issue this level of drawing detail, our guide to the best home automation companies in Hyderabad covers what to check before you sign.

Frequently asked questions

How deep and how wide should a curtain pocket be for motorised curtains?

About 120–150mm wide and 150mm deep for a single track; 200–250mm wide and 150mm deep for the more usual sheer-plus-blackout pair, with the two tracks 80–120mm apart. Depth is the number people get wrong — 150mm keeps the track, carriers and fabric heading above the sightline and leaves room to work. A 75–100mm pocket, which is what gets built when nobody specifies it, leaves the hardware visible and may not physically accept a motor.

Do motorised curtains need a bigger pelmet than manual ones?

Only at the motor end. The motor is a 40–60mm cylinder, 250–400mm long, sitting inline at one end of the track, so the pocket must continue at least 400mm past the last carrier there, and that end needs a 5A point. Choose the motor end at drawing stage — ideally the end nearer a wall or corner and opposite the side the fabric stacks on.

How much stack space do curtains need at the sides of a window?

Roughly 12–18% of the track length per side, so a 3,000mm track needs about 350–500mm of wall beyond each side of the glass. Extend the track 300–500mm past the reveal on each side. Size it to the window instead and the open curtain permanently covers 200–300mm of glass on each side, which is the most common disappointment with curtains.

Can a curtain pocket and a cove light share the same recess?

No — keep them adjacent but separate, with a 50–75mm plaster fin between. Sharing one recess means the cove lights up the track and the motor while the fabric blocks the cove's throw. If you want the fabric lit, add a separate low-output grazing strip on the room-side face of the fin, on its own dimmable channel.