Fire Door Sizes in Bangladesh: Standard Dimensions, ft–mm Conversion and Handing

Standard fire door sizes in the Safety Plus catalogue

Fire doors are made in a tested range of sizes. Within that range a manufacturer can usually build to your exact opening; outside it, the rating may not be supported by test evidence. The Safety Plus catalogue sets out the following ranges.

Single leaf widths are offered in steps of about 100 mm from 750 mm upward, and the standard heights are 2,100 mm and 2,400 mm. All models share a 50 mm door thickness and 1.2 mm skin. For louver and shaft doors, see the louver door and shaft door guide.

When an opening is wider than about 1,200 mm, it normally moves to a double leaf door. That is not just a manufacturing preference: very wide single leaves are heavy, strain hinges and closers, and may fall outside the tested size range.

Converting feet to millimetres (and back)

Architects in Bangladesh often draw in millimetres, while contractors, shops and many buyers talk in feet. The conversion is simple — 1 ft = 304.8 mm and 1 in = 25.4 mm — but the rounding catches people out.

And the reverse, for reading metric drawings:

The lesson: a "7 ft" door and a "2,100 mm" door are not the same. Online listings such as the 3 ft × 7 ft or 4 ft × 8 ft doors use nominal sizes. Before ordering, ask the supplier to confirm the actual frame outside dimensions in millimetres and check them against the opening on site.

Opening, frame, leaf and clear opening: four different numbers

Most sizing disputes come from people using the same word, "door size", for four different measurements.

The structural opening must be larger than the frame to leave a fixing and sealing gap; that gap is then closed with grout or fire-stopping material as the installation instructions require. The frame is larger than the leaf because it includes the jambs and head. The leaf is larger than the clear opening because, when the door opens to 90 degrees, the frame stop and the 50 mm thickness of the leaf itself intrude into the passage.

Hardware reduces clear width further. A panic bar projects from the push side of the leaf, and a door that cannot open fully because of a wall return or a door holder position loses more width again. If your fire safety plan or a hospital equipment list sets a minimum clear width, give that number to the supplier and ask them to work out the leaf and frame size from it, rather than the other way round. Building codes, including BNBC 2020, set requirements for exit widths; your consultant should confirm the figure that applies to your occupancy.

Door handing and swing direction

Handing describes which side the hinges are on and which way the door swings. A common convention used by door and hardware suppliers is:

• Stand on the outside of the door (the corridor side, or the side from which you would need a key).
• If the hinges are on your left and the door opens away from you, it is left hand (LH).
• If the hinges are on your right and the door opens away from you, it is right hand (RH).
• If the door opens towards you, add "reverse": LHR or RHR.

Conventions differ between suppliers and countries, so the safest method is a simple plan sketch for each door showing the hinge side and swing arc. Fire doors cannot be re-handed on site the way some timber doors can, because hardware preparation, the closer position and panic device are all set at the factory.

Swing direction is a safety question as well as a fitting one. Exit doors serving larger numbers of people are commonly required to swing in the direction of escape, and doors must not swing into a stair in a way that blocks the escape width. Confirm the direction with your consultant for every door on an escape route.

For double doors, also state which leaf is the active leaf (the one people normally push) and which is inactive. Pairs need a coordinator so the inactive leaf closes first, and an astragal to cover the meeting edges.

Sizing for hospitals, warehouses and plant rooms

The right size depends on what passes through the door, not just on people.

• Hospitals and clinics. Bed and trolley routes need generous clear widths, which often pushes corridors and wards to double leaf or unequal pair doors. The stainless steel SFD 503 model is designed for hospital and storage use. See the hospitals and healthcare page for related products.
• Warehouses and factories. Pallet trucks and material trolleys need clear width plus clearance for handles and loads. Check trolley widths before fixing the opening.
• Plant rooms and electrical rooms. Doors must pass the largest piece of equipment that will ever be installed or replaced, such as a transformer, switchboard section or pump. A door sized only for people may force a wall to be broken later.
• Stair cores. Doors must not reduce the stair landing width needed for escape. Leaf size and swing must be planned with the stair layout.

When in doubt, size for the largest item and the escape requirement, then choose single or double leaf to fit.

Vision panels, colour and other details to fix at the sizing stage

A few details are best decided together with the size because they are built into the leaf at the factory:

• Vision panel. The Safety Plus catalogue uses 6 mm tempered vision glass with a standard exposed area of 450 × 150 mm. Larger or differently placed panels must stay within what the door's test evidence covers.
• Hardware preparation. Closer, panic device, lock and hinge positions are cut and reinforced during manufacture, so choose the fire door hardware set before the order is placed.
• Colour. Safety Plus offers the full RAL colour range, subject to quantity.
• Threshold and undercut. If a floor finish such as tiles or epoxy will be added later, tell the supplier the finished floor level so the bottom gap is correct after the floor is laid.

Once these are fixed, send the schedule through the request a quote page, or review the fire rated doors range. For writing the full tender description, use the fire rated door specification checklist.

Frequently asked questions