Double-Leaf Loft Doors: The Right Choice for Wide Openings
The knock-through between the front and back rooms of a Victorian terrace, the through-lounge in a 1930s semi, the kitchen-diner someone opened up in a period conversion: British homes are full of wide openings that were never meant to take a single door. A double-leaf loft door closes them with two hinged steel and glass leaves that meet in the middle, so nobody is heaving one oversized panel shut every evening. Manufaktur X builds the pair to your exact dimensions, each leaf anywhere from 600 to 1,400 mm wide and 1,800 to 3,000 mm high, priced live in the 3D configurator, made in the EU and delivered to the UK in around 4-6 weeks with customs and duties taken care of. Below: the width at which two leaves start to make sense, how to measure a reveal that is out of square, how much floor the swing arcs eat up, and where the money actually goes.
Not sure whether your opening wants one leaf or two? Type the width into the loft door configurator, flick between single and double, and watch the leaves, swing arcs and price change in the 3D preview.
Two leaves make sense when a single leaf would have to be wider than 1,400 mm, or heavier than you want to be swinging every day. Manufaktur X makes each leaf to measure from 600 to 1,400 mm wide and 1,800 to 3,000 mm high, adds side panels and a transom for very wide or tall openings, and shows the fixed price live as you configure.
A double-leaf loft door is an interior door in which two hinged steel and glass leaves close a single opening and meet in the middle without a fixed post between them. As a result, the full clear width can be opened up, while each leaf stays lighter and needs less swing room than one wide leaf would.
The short version
The standard defines the two terms structural opening size and nominal size.
Source: Door leaf sizes to DIN 18101 | Windows and doors | Construction and function | BauNetz Wissen
- Go double as soon as a single leaf would be wider than you can comfortably swing and keep plumb; our configurator data show that 52% of configurations went for the double door (233 sessions).
- Every leaf is made to your measurements, 600-1,400 mm wide and 1,800-3,000 mm high; side panels (100-1,000 mm each) and a transom (200-1,000 mm) carry the steel frame across a very wide or tall reveal.
- Each leaf needs roughly its own width of clear floor on the side it opens to; hinge side, opening angle and the magnetic catch decide whether a pair works once the living room is furnished.
- Measure the clear opening at several points, keep the smallest figure and knock off about 5 mm a side (left, right, top) for the fitting gap.
- Price follows glazed area, the second leaf, how many glazing bars you add, the glass type, and toughened versus laminated; the live price updates as you change each one.
What matters most for a wide reveal
| Insight | What it means for your opening |
|---|---|
| Two leaves are about handling as much as looks | A single leaf can go up to 1,400 mm, but a pair halves the weight and the swing arc each set of hinges has to cope with. |
| Our configurator data show what people actually build | Median leaf width 985 mm (p10-p90 760-1,365 mm, 286 sessions), median height 2,125 mm (p10-p90 2,000-2,800 mm, 272 sessions): wide openings are the norm for this door. |
| The swing arc is the bit people forget | Allow roughly one leaf width of clear floor per leaf on the opening side; sofas, sideboards and radiators inside that arc are the usual culprits. |
| Wide reveals are rarely square | The wider the opening, the bigger the gap between its width at the top and at the bottom tends to be; the smallest reading minus the fitting gap is the only safe size to order. |
| Steel and glass only, hinged or pivot | Powder-coated steel frame, toughened or laminated safety glass, five glass types; no timber leaf and no sliding version. |
When does a two-leaf steel and glass door beat a single one?
A pair of leaves is the right call as soon as one leaf would have to be wider than you can swing and hold plumb without a struggle; at Manufaktur X a single leaf tops out at 1,400 mm, so anything wider needs either two leaves or one leaf with side panels.
Below that limit it comes down to preference, and three things settle it. First, the weight of glass and steel hanging off one set of hinges, which grows with glazed area, so a leaf that is both wide and tall is the one that wears out hinges and wrists first. Second, the arc that leaf sweeps across your floor. Third, how often you actually close the whole passage. A wide single leaf suits a door that stands open all day; two leaves suit the kitchen-to-living-room passage you shut every evening. Among people planning a steel and glass door for a real opening, our configurator data show that 52% of configurations went for the double door (233 sessions), a slim majority.
Go double if the opening is wider than one leaf or you want a mirrored view from the sofa. Go single with side panels if the point is daylight through the wall and you rarely carry anything wider than yourself through it.
One broad leaf or a mirrored pair
One leaf gives you a single uninterrupted expanse of glass, one handle and fewer hinges to line up. A pair gives you symmetry, half the swing on each side, and the everyday habit of opening only the leaf nearest you while the other stays shut.
Hinged pair or pivot pair
Both leaf counts come as hinged or pivot doors. A hinged door hangs on side hinges; a pivot door turns on an offset pivot hinge in the frame and needs no fixing into the floor, which is why it is the one to choose over underfloor heating or for a very tall leaf. Hinged is still the everyday choice: 60% of configurations chose hinged as the door type (241 sessions).
How big can a double loft door be?
Each leaf of a Manufaktur X double door is made to measure anywhere between 600 and 1,400 mm wide and 1,800 and 3,000 mm high, and side panels of 100 to 1,000 mm on either side plus a transom of 200 to 1,000 mm carry the frame across a very wide or very tall reveal.
Those are configurator limits, not a size grid. You enter the millimetre figure your opening needs and the frame is welded to it; no rounding up to the next stock width and no packer strip to hide the difference. Side panels and the transom are fixed glazed sections within the same frame, so the two leaves can stay at a width you can handle day to day while the steel fills the whole aperture. That is the practical answer to a tall Victorian opening or a knocked-through kitchen-diner in a new-build flat. If what you are really after is the glazed wall with no door in it at all, that is a different product: the fixed steel and glass room divider.
The four made-to-measure dimensions
Leaf width 600-1,400 mm, door height 1,800-3,000 mm, left and right side panels 100-1,000 mm each, transom height 200-1,000 mm. Each of the three fixed sections switches on or off on its own, so a pair with a transom and no side panels is as normal as the full frame, and a side panel on one side only is the usual answer for an opening close to a corner.
Which configuration suits which opening
| Configuration | Covers | Choose it when |
|---|---|---|
| Single leaf | One leaf up to 1,400 mm wide, one swing arc | one leaf fills the opening and it stands open most of the day |
| Double leaf | Two leaves meeting in the middle, each with half the arc | you close the passage daily or want a symmetrical view |
| Double leaf + side panels | Two leaves plus fixed glazing left and/or right, 100-1,000 mm each | the reveal is wider than two manageable leaves and you want the walk-through in the centre |
| Double leaf + transom | Two leaves plus a fixed section above, 200-1,000 mm high | the opening is taller than the leaves you want to swing, as it often is under a period ceiling |
Typical sizes from our own data
Our configurator data show a median leaf width of 985 mm (p10-p90 760-1,365 mm, 286 sessions) and a median door height of 2,125 mm (p10-p90 2,000-2,800 mm, 272 sessions). Where side panels are switched on, the median left panel is 500 mm (118 sessions) and the median right panel is also 500 mm (112 sessions). In plain terms: most pairs are planned for openings well beyond a standard internal door, the tallest tenth sits far above any off-the-shelf frame, and side panels tend to be half-metre strips of light rather than a second glazed wall.
Measuring a wide opening for a pair of leaves
Measure the clear width and height of the opening at several points, take the smallest of each, and knock off about 5 mm a side (left, right and top) for the fitting gap; what is left is the frame size you enter in the configurator.
Here is what we watch for on wide sizes: the broader the opening, the more any difference between its width at the top and at the bottom shows. A hand-plastered reveal in an older house can be several millimetres tighter at head height than down at the skirting, and a Victorian knock-through that a builder finished decades ago rarely runs true. A single door hides that. A pair does not, because two leaves have to meet cleanly in the centre, and a frame forced into a twisted reveal shows every millimetre right at that meeting edge. The spread between your biggest and smallest readings also tells you how much packing the frame will need on the day.
Measuring step by step
- Measure the clear width at the top, middle and bottom of the opening.
- Measure the clear height on the left, in the middle and on the right.
- Hold a spirit level against both faces of the wall to check whether the reveal leans.
- Note anything that sits inside the frame line: skirting boards, a radiator, light switches, sockets.
- Keep the smallest width and the smallest height you found.
- Take off about 5 mm on each side: left, right and top.
- Enter the result in the loft door configurator; general questions about entering dimensions are covered in the FAQ.
Why the smallest reading minus 5 mm is the size to order
The gap is there so the pre-drilled frame can be wedged plumb inside an opening that is not. The frame fixings close it up, not foam, not a lining, not an architrave. Order to the widest reading and the frame will not go in at the narrowest point; order to an average and it goes in at the bottom and jams at the top.
Opening measured? Put the smallest width and height into the double-leaf loft door configurator and compare a pair with and without side panels for the same reveal before you settle on glass and colour.
On a Victorian knock-through I never trust the builder's opening size. I measure the plastered reveal at three heights myself, take the smallest, and the pair of leaves meets cleanly every time.
James W.
Bespoke furniture maker, London
Fitting two leaves into a furnished living room
A double loft door works in a living room when both leaves can swing clear on the opening side, the hinge sides suit where people walk and where the furniture sits, and the glass type gives you the sightline you want between the two rooms.
Three configurator settings carry that planning: hinge side, opening angle and the optional magnetic catch. Furniture decides all three. The sideboard on the wall beside the opening, the radiator under the bay window, the sofa that ends closer to the passage than the floor plan suggested. In our experience, the thing customers most often get wrong is drawing the swing arc on an empty plan and then forgetting it once the room is furnished.
How much swing room does a pair need?
Each leaf needs about its own width of clear floor on the side it opens to, so two 900 mm leaves need roughly 900 mm of clear arc either side of the opening. Where a wall or radiator sits inside that arc, the opening angle setting limits how far a leaf travels, turning a collision into a defined stop. Tape both arcs out on the floor before you order; that five-minute check catches more planning mistakes than any drawing.
Hinge side, opening angle and magnetic catch
Choose the hinge side (left or right) standing in the room you open into, and think about where the light switch is, so nobody is reaching behind a glass leaf in the dark. The magnetic catch is a closing system in which magnets in the frame hold the door shut and stop it drifting open in a draught; a light pull or push releases it. On a pair it is what keeps the second leaf reliably shut while you only use the first, with no door closer on show.
Glass type and glazing bars across two leaves
Clear glass keeps the two rooms visually one, and it is the default by a clear margin: 56% of configurations chose clear as the glass type (167 sessions). Frosted or textured glass gives privacy to a home office behind the door, while smoked and dark smoked glass take the glare off a bright kitchen seen from the sofa. Glazing bars go in horizontally and vertically in whatever number you like; on two leaves a dense grid looks heavier than the same grid on one, so we usually suggest fewer bars on a pair, with identical spacing on both leaves so the pattern carries across the meeting edge. Handles come as crescent, discreet, elongated or none at all; elongated was the pick in 47% of configurations (182 sessions). The powder-coated frame takes any RAL colour, with anthracite, deep black, pure white, cream white and grey-brown listed as ready picks; one colour across frame, side panels and bars is what makes the pair read as a single piece.
What a two-leaf steel and glass door costs
The price of a double-leaf loft door goes up with glazed area, the second leaf, the number of glazing bars, a special glass type and the choice of toughened or laminated safety glass; Manufaktur X shows the resulting fixed price live in the configurator as you change each setting.
You buy direct from the manufacturer, so the figure in the configurator is the figure on the invoice, and delivery to the UK is a flat £349 per order, shown in the basket, with customs and duties already dealt with. UK buyers often ask whether a steel door costs more than a timber one. This product has no timber leaf to compare it with, so the honest answer is that the money is in glazed area and safety glass, not in wood. Colour is a lever people underestimate: 28% of configurations chose a custom colour for the RAL choice (229 sessions), so more than a quarter go beyond the six listed tones, and a free-choice RAL colour is priced in the same live view. If you would rather spread the cost, the order can be paid in instalments with Klarna.
Price factors side by side
| Price factor | What changes | Effect on price |
|---|---|---|
| Leaf size (glazed area) | More steel and more glass per leaf | Goes up with width and height |
| Single versus double leaf | Second leaf, second set of hinges, second handle | A pair costs more than a single leaf of the same overall width |
| Number of glazing bars | Every horizontal or vertical bar is welded and powder-coated | Goes up with each bar |
| Glass type (clear / frosted / smoked / dark smoked / textured) | Special glass in place of clear | Clear is the base; the other four cost more |
| Toughened (ESG) or laminated (VSG) | 4 mm toughened pane or laminated two-pane build | Laminated costs more than toughened |
| Listed RAL or custom colour | One of six listed tones or your own RAL | Custom colour is priced live in the configurator |
| Side panels / transom | Extra fixed glazed sections in the frame | Each section adds area, and therefore price |
There are no hidden percentage surcharges behind this table; the live price is simply the sum of these factors for your size.
| Product | From | Note |
|---|---|---|
| Loft Door | £815 | Lowest possible option |
| Room Divider | £1,900 | Steel + laminated glass, custom width |
| Large Shelf | £2,750 | Solid wood, steel frame, floor-to-ceiling |
| Dining Table | £1,360 | Solid wood, steel frame |
| Coffee Table | £995 | Solid wood, steel frame |
| Bench | £945 | Solid wood, steel frame |
| TV Stand | £1,325 | Solid wood, steel frame |
| Pipe Shelf | £915 | Modular pipe shelf |
Toughened or laminated for large leaves
Toughened glass (ESG) is a 4 mm pane that breaks into blunt granules rather than sharp shards. Laminated glass (VSG) is two 3 mm panes bonded by a 1 mm interlayer; if it breaks, the pieces stay stuck to the interlayer rather than falling out. For the large panes of a pair we recommend laminated: a leaf-sized pane that stays put in its frame is easier to live with than granules all over the floor, and the two leaves swing towards each other, which is exactly where an accidental knock happens. This is our recommendation, not something any standard requires.
EN 12150-1 is the European product standard for thermally toughened soda lime silicate safety glass used in buildings; it defines the product and its properties, not the size at which a door has to use it.
Source: DIN - EN 12150-1
Mistakes we see with double doors, and the fix for each
The most common problems with a pair of loft door leaves come from planning, not production: an opening taken off the drawing rather than the wall, a swing arc nobody thought about, a skirting board or radiator inside the frame line, and a fitting gap that never got subtracted.
In our experience, the most common reason a made-to-measure door does not fit is a badly measured opening, not a production fault, and a pair punishes it harder than a single leaf because every millimetre of twist shows where the two meet. Not sure about your sketch? Send it over via the contact page before you order.
- Drawing dimension instead of a site measurement - result: the frame does not fit, or leaves a visible gap - fix: measure the opening as built, smallest clear width minus the fitting gap.
- Swing arc forgotten - result: a leaf hits the sofa or radiator and only opens halfway - fix: keep both arcs clear or set an opening angle.
- Skirting, radiator, switch or socket inside the frame line - result: the frame cannot sit flat against the wall - fix: note them while measuring and move or trim them before the door turns up.
- Fitting gap not subtracted - result: the frame cannot be wedged plumb, or will not go in at all - fix: take off the 5 mm a side.
- Hinge side chosen from the wrong room - result: the leaves open into the walkway or hide the light switch - fix: decide left or right standing in the room you open into.
- Wall with nothing solid to fix to - result: the screws of a wide, heavy frame do not hold - fix: use a wall that can take it, or put solid noggins into a stud wall first.
- Uneven wall not packed out - result: twisted frame, the two leaves do not meet cleanly - fix: washers behind the frame wherever a gap shows, as described under installation.
Installing the pair: wall, frame and who does it
A Manufaktur X double door is fitted by screwing the pre-drilled, welded steel frame straight to a solid wall, set plumb with wedges and a spirit level; it ships with fitting instructions and can be put in by a competent DIYer or a local joiner.
There are four parts to it. Check that everything has arrived complete and undamaged and that both leaves have room to open and close. Offer the frame into the opening, hold it with wedges and get it dead plumb with a spirit level, because a frame that leans is the reason a door later refuses to close. Drill through the pre-drilled holes into the wall, with the holes sitting about 8 mm from the wall side and 10-12 mm from the door side of the profile, put in the supplied screws and tighten them carefully without pulling the frame out of true; if a wide frame wants more fixing points, you can drill extra holes in it. Where an uneven wall leaves a gap, a washer between frame and wall takes the strain out. Push the plastic caps into the holes on the door side and try both leaves; if one binds, adjust it. No lining, no foam, no separate fixing kit: the frame is the finished article. It is an interior door and should carry nothing beyond its own glass.
Which walls will take a wide double frame?
Solid walls of concrete, brick, block, steel or timber will carry the frame, and plasterboard or timber-stud walls are fine provided there is something solid behind them to fix into. A double frame is wider and heavier than a single one, so on a stud wall the first thing to check is what sits behind the screw points.
Do it yourself or get a joiner in
The step-by-step instructions make the job manageable, and a wide double frame is far easier with two people, one holding it while the other sets the wedges. Manufaktur X does not install. If you would rather not tackle it yourself, a local joiner will fit a pre-drilled steel frame like this in an afternoon.
Ordering a double-leaf loft door: configure, price, delivery
A double-leaf loft door from Manufaktur X is configured online in a 3D configurator with the fixed price shown live, made to measure in the EU and delivered to your door in the UK by pallet courier in around 4-6 weeks.
Why manufakturx.co.uk for a pair
- Made to measure, not a size grid: each leaf 600-1,400 mm wide and 1,800-3,000 mm high, side panels and transom to the millimetre your reveal needs.
- Direct from the maker: the price you see in the configurator is the price you pay, delivery a flat £349 per order, no dealer in between.
- Powder-coated steel and safety glass: any RAL colour on the frame, five glass types, toughened or laminated chosen per project.
- EU-made with a stated lead time: around 4-6 weeks from order to delivery, shown in the basket before you pay, customs and duties taken care of.
From configurator to fitted door in four steps
- Configure: door count double, hinged or pivot, leaf width and height from your measured figures, side panels and transom on or off, glass type, toughened or laminated, glazing bars, hinge side, handle, magnetic catch, RAL colour. The 3D preview and the price update with every change.
- Order: delivery cost and lead time appear in the basket before you pay. There is no technical drawing to download, so hang on to your own measuring sketch.
- Production: the frame is welded and powder-coated to your dimensions in the EU, around 4-6 weeks depending on the project and how busy the workshop is.
- Delivery: by pallet courier in transport packaging. Should anything arrive damaged, photograph it thoroughly and send us the pictures.
From here you can configure a double-leaf loft door with live pricing, or have a look at the rest of our made-to-measure furniture in steel, glass and solid wood, all built on the same principle: your dimensions, one fixed price, direct from the maker. More planning guides are on the blog.
By Q2 2027 we expect double-leaf configurations to make up the majority of loft door orders for openings created in open-plan renovations, because the passage between kitchen and living room is the one most households want to close of an evening without losing the view.
Sizing your pair: five decisions in order
| Decision | Take this option if | Take the other if |
|---|---|---|
| One leaf or two | Two - the opening is over 1,400 mm or you close it daily | One plus side panels - you mainly want light and rarely open the passage fully |
| Hinged or pivot | Pivot - underfloor heating or a very tall leaf | Hinged - the standard case, chosen in 60% of configurations |
| Glass type | Clear - the two rooms should read as one | Frosted, textured or smoked - privacy for an office, or a bright kitchen to tone down |
| Toughened or laminated | Laminated - large leaves, our recommendation for a pair | Toughened - smaller leaves where the lower price matters more |
| Side panels / transom | On - the reveal is wider or taller than two manageable leaves | Off - the two leaves already fill the aperture |
Your opening is wider than one leaf ought to be. Enter the smallest measured width and height, choose two leaves, side panels or a transom, pick glass and colour, and the configurator shows the fixed price for exactly that door - EU-made and delivered to the UK in around 4-6 weeks.
In Parisian flats I draw both swing arcs on the floor plan with the furniture in place before I choose a hinge side; a symmetrical pair of steel leaves only looks right when both can open fully.
Camille L.
Interior architect, Paris
Questions we get about double-leaf loft doors
Can a pair of loft door leaves go over underfloor heating?
Yes, and the pivot version is the safest choice for it, because its offset hinge sits in the frame and nothing gets drilled into a heated screed. A hinged pair is likewise fixed through its frame to the wall rather than the floor, so either way the floor is left alone; what you do need to check is that the wall can carry the frame.
Do both leaves have to open, or can one stay shut day to day?
Both leaves are hinged and open, but most households only ever use the leaf on the walking side and leave the other shut. The magnetic catch in the frame holds a closed leaf against draughts, and the hinge side you choose in the configurator decides which leaf sits in the walkway. Plan for both leaves open when you are moving furniture, and one leaf for every day.
Which glass is safer for a large pair, toughened or laminated?
Both are safety glass, but they fail differently. Toughened (ESG) is 4 mm glass that breaks into blunt granules; laminated (VSG) is two 3 mm panes bonded by a 1 mm interlayer that holds the pieces in place. For large leaves Manufaktur X recommends laminated, because a big pane that breaks stays in the frame instead of scattering granules across the floor.
Are steel loft doors dearer than timber doors?
A like-for-like comparison is not possible within a Manufaktur X configuration, because the door is only ever built with a steel frame and safety glass and has no timber leaf. With steel and glass the cost is in glazed area, the second leaf, glazing bars, glass type and toughened versus laminated, not in timber. The configurator shows the fixed price for your exact size, so you can set it against any joinery quote you already have.
What if my wide opening is not a true rectangle?
Order the frame to the smallest width and height you measured, less about 5 mm a side, and take up the rest when you fit it. The frame is wedged plumb, screwed through its pre-drilled holes, and any gap to an uneven wall is packed with a washer so the frame is not pulled out of true. A twisted frame is the main reason two leaves fail to meet cleanly, so get it plumb before you tighten anything.
The decision only runs one way. Opening width settles one leaf or two; furniture settles swing arc, hinge side and opening angle; the smallest of several readings less the fitting gap settles the frame size. With those three figures written down, all that is left is glass, colour and the fixed price the configurator shows for them.
