Lintel Height and Door Frame Dimensions

The lintel is the most forgotten element in an Indian house. It is cast by the mason weeks or months before anyone thinks about doors, windows or interiors, usually from a single instruction — "lintel at 7 feet" — that nobody writes down precisely. Seven feet from what? From the rough slab or the finished floor? To the underside of the lintel or to the top of the door frame? Seven feet is 2134 mm, not 2100 mm. A difference of 50–75 mm sounds trivial on site, but it decides whether a standard 2100 mm door shutter fits, whether the window heads line up with the door heads, and whether the false ceiling can run cleanly above them.

The door frame — the chaukhat — has the same problem from the other side. Frames are fixed into walls with holdfasts grouted into the masonry, so they are effectively permanent. If the opening is too small, the frame is forced or cut; if it is too large, the gap is packed with mortar that cracks; if the lintel is too low, the shutter is trimmed until its proportions look wrong. This blog's guide to standard door and window sizes sets out the shutter sizes. This article goes one layer deeper, into the lintel and the frame that hold them, and gives the dimensions a site needs to get them right the first time.

All dimensions here are in millimetres, measured from finished floor level (FFL) unless stated otherwise. Standard sizes follow the NBC-derived bye-law figures used in this blog's door guide — 900 × 2100 mm for habitable-room doors and 750 × 2000 mm for kitchens, baths and WCs — and the common trade practice of a 100 × 60 mm frame section. Structural figures for lintels are typical values for residential openings and must be confirmed by the project's structural engineer.

What a lintel is, and how it got to 2100 mm

A lintel is the horizontal member that spans the top of an opening and carries the wall above it to the solid wall on either side. Indian builders have used lintels for thousands of years. Early temples were trabeated — built of posts and beams — and their doorways were spanned by single stone lintels, often carved with guardian figures and deities. Arches arrived in force with the Delhi Sultanate and were refined by the Mughals, letting masonry span wider openings without one long stone. Vernacular houses continued to use timber lintels over doors and windows, and in many old homes in Gujarat and Rajasthan a carved timber lintel is part of the doorway's decoration.

The modern Indian lintel is reinforced cement concrete, cast in place over a temporary shuttering or precast and lifted into position, often with a chhajja — a projecting sunshade — cast with it. The 2100 mm head height that now governs almost every Indian door and window comes from the standardisation of the twentieth century: public works departments and building bye-laws fixed door heights of about 2.0–2.1 m, factories began making shutters to those sizes, and the masonry around them followed. Today the National Building Code of India 2016 and the bye-laws derived from it set the habitable-room door at 0.90 × 2.1 m and the bath and WC door at 0.75 × 2.0 m, and the trade works to these numbers.

The 2100 confusion: frame height, shutter height or lintel height?

Most site mistakes about lintels come from one ambiguity. When someone says the door is 2100, they may mean any of three things: the shutter is 2100 mm tall; the frame, measured outside, is 2100 mm tall; or the lintel soffit is at 2100 mm. These are different numbers, separated by the frame section and the clearances, and they produce different doors. This blog's door guide follows the clearest convention: 900 × 2100 mm is the shutter, and the opening is sized around it. That convention is the one used here.

Working upwards from the finished floor, a 2100 mm shutter needs a floor gap of about 6–10 mm so it clears the floor and any doormat, the 2100 mm of the shutter itself, a head gap of 2–3 mm, and then the frame head. With a 100 × 60 mm frame and a rebate of about 12 mm, the frame head adds about 48 mm above the shutter top (60 mm face minus 12 mm rebate). The frame's outer top therefore sits at about 2156–2161 mm, and allowing a few millimetres for fixing, the lintel soffit should be at about 2160–2175 mm above the finished floor. If the lintel is cast at exactly 2100 mm, the same frame will only take a shutter of about 2030–2040 mm — which is what many builders actually supply, and why some 'standard' doors look squat.

Fig. 1 shows how the numbers stack up in a typical flat with a 3000 mm floor-to-floor height. The door shutter top and the window head share the 2100 mm line; the door frame top is at about 2160 mm; the lintel, 150 mm deep, sits above that; and above the lintel, in an RCC-framed building, there is usually a beam whose soffit — its underside — may be anywhere between about 2350 and 2550 mm above the floor depending on its depth. That leaves only a few hundred millimetres between the head line and the beam, which is why the false ceiling, the loft above a wardrobe and the curtain track must all be planned with the lintel level in mind. Keeping the false ceiling at least 300 mm above the door head, as this blog's ceiling height guide recommends, means a ceiling level of 2400 mm or more.

Door frame dimensions: sections, rebates and clearances

A door frame has two legs (jambs) and a head, joined at the top corners and fixed into the masonry. Its section is described by two numbers: the depth across the wall (often 100 mm) and the face width seen in elevation (often 60 mm). The shutter closes against a rebate, a step cut along the inner edge of the frame, typically 12–15 mm deep and slightly wider than the shutter thickness. In Indian construction, the frame usually runs down into the floor finish so that its legs are buried 25–50 mm below FFL and protected by the tile; in older houses, the legs often extended as 'horns' at the head into the masonry for extra anchorage.

Clearances that keep a door working

The gaps around a shutter are small but critical. At the sides and head, 2–3 mm between shutter and rebate lets the door close without binding while keeping light and sound leakage low; less than that and the shutter sticks in the monsoon, when timber and boards take up moisture. At the floor, 6–10 mm is usual — enough to clear the tile and a thin mat; bedrooms with thick rugs or rooms where an air-conditioner's return air must pass under the door may need 12–15 mm or a louvred panel instead. Bathroom doors need a floor gap that clears any threshold or step and allows the room to ventilate. Every shutter of 2100 mm height should hang on three hinges, as this blog's door guide recommends; heavy main doors and tall doors need four.

From shutter to opening: working out the sizes

Once the shutter size and the frame section are fixed, the masonry opening can be calculated rather than guessed. The width works the same way as the height: the shutter width plus two side gaps, minus the two rebates, plus the two frame faces, gives the frame's outer width; add a fixing tolerance of 5–10 mm per side for packing and the opening in the wall is found. For a 900 mm shutter in a 100 × 60 mm frame, that comes to a frame of about 1000 mm and a masonry opening of about 1000–1020 mm — the 'roughly 1000 mm' figure given in this blog's door guide. A 750 mm bathroom shutter needs an opening of about 850–870 mm, and a 1200 mm double main door in a 125 × 75 mm frame needs about 1330–1350 mm.

The clear passage matters for accessibility. A 900 mm shutter in a standard frame gives roughly 810–840 mm of clear width when open, close to the 815 mm (32 inch) minimum in the ADA Standards that this blog's door guide cites and the barrier-free expectations in India's CPWD Harmonised Guidelines. That is why 900 mm is the practical minimum shutter for any room an elderly parent or a wheelchair user must enter, and why a 750 mm bathroom door, although it meets the bye-law, is worth upgrading to 900 mm in at least one bathroom.

Lintel size, bearing and reinforcement

A lintel must be deep enough to carry the masonry above, and it must sit far enough into the wall at each end to pass that load safely into the jambs. For the small spans of residential doors and windows, Indian practice has settled on a few typical sizes. The table below gives commonly used values for RCC lintels in 230 mm brick or block walls carrying normal loads; they are rules of thumb for estimation and coordination, not a structural design. Openings under a heavy load — a beam, a column, a concentrated load or a full storey of masonry — and any opening wider than about 2.4 m need a designed lintel or beam from the structural engineer, working to IS 456 for reinforced concrete.

Bearing is the length of lintel resting on the wall at each end. A common minimum is 150 mm, and 200 mm or the depth of the lintel, whichever is greater, is better practice; short bearings crush the masonry under the lintel end and show up later as diagonal cracks from the top corners of the opening. Reinforced concrete lintels should follow IS 456 for concrete grade (M20 or better for reinforced work) and for nominal cover to the steel, typically 20–30 mm depending on exposure, so that the bars do not rust and spall the concrete. Stirrups — small closed links, often 6 mm bars at about 150 mm centres — hold the bars in position and resist shear near the supports.

Lintel bands in earthquake zones

Large parts of India, including Surat and Ahmedabad, lie in seismic zone III, and parts of Kutch, the Himalayan belt and the north-east lie in higher zones. In load-bearing masonry buildings in these areas, IS 4326 — the Indian Standard for earthquake-resistant design and construction of buildings — calls for horizontal reinforced concrete bands at key levels, including the lintel level, running continuously around all walls. Instead of separate lintels over each opening, the band ties the walls together like a belt and the lintels become part of it. In RCC framed buildings, where beams and columns carry the loads and the walls are infill, separate lintels are normal, but many engineers still specify a lintel-level band in long infill walls to control cracking. Either way, the decision belongs to the structural engineer, and the interior team should know which system has been used before cutting any chase or opening near lintel level.

Windows, ventilators and the head line

The single most visible benefit of a well-set lintel level is a clean head line: every door shutter, window head and ventilator top in a room sits on one horizontal line at about 2100 mm. Curtain tracks, pelmets, loft bottoms and cove details can then run along that line, and the room looks orderly without any decoration at all. When the line is broken — a window 75 mm higher than the door beside it, a ventilator lower than both — the eye notices immediately, and every interior element has to be adjusted to hide it.

Window frames in aluminium, UPVC or timber follow the same logic as door frames: the window size given on a drawing should be the frame size, and the masonry opening needs a fixing tolerance around it — commonly 10–15 mm per side for aluminium and UPVC frames, which are fixed with anchors and sealed with silicone. With a window head at 2100 mm and a 900 mm sill, the standard window is 1200 mm high. Bathroom and kitchen ventilators sit high for privacy and exhaust, usually with their heads at or near the same lintel level. Where the lintel is cast as one continuous band across a wall, all of these openings can be adjusted in width without changing the head.

Tall doors, beams and false ceilings: the present and future

The fastest-changing part of this topic is the door height itself. Many new homes now want doors of 2400 mm or full height to the false ceiling, often with concealed hinges, flush aluminium frames that disappear into the plaster and shutters finished to match the wall. These doors look calm and generous, but they collide with the lintel and the beam. In a flat with a 3000 mm floor-to-floor height, the beam soffit is often only 2350–2550 mm above the floor, so a 2400 mm door frame may leave no room for a lintel at all; the opening is then formed directly under the beam, or the beam itself acts as the lintel. That must be decided at the structural stage, not discovered during interiors.

Tall doors also change the frame and hardware. A 2400 mm shutter is heavier and more prone to bowing, so it needs four hinges or a pivot, a thicker or stiffer core, and often a concealed aluminium or steel frame that holds its geometry better than timber. The false ceiling has to rise with the door: if the door runs to 2400 mm, the ceiling around it should be at least at that level, which means fewer coves and drops near doors. Looking ahead, prefabricated door sets — frame, shutter and hardware supplied as one factory-made unit fitted into a precisely sized opening — are spreading in Indian projects, and they depend completely on accurate lintel levels and opening sizes. The more the industry moves to factory-made doors, the more the lintel needs to be set to the millimetre.

The prices above are indicative October 2026 ranges for a standard bedroom-size frame, supplied and fixed with holdfasts or anchors, before the shutter, hardware and finishing. They vary widely with timber species, section size, city and quantity, and should be checked against written quotes. As this blog's WPC guide points out, the frame decides whether a door still closes in year five: spending on a WPC or stone frame in a wet zone is better value than an expensive shutter on a frame that rots.

Site rules for lintels and door frames

• Fix the convention in writing: '900 × 2100 is the shutter; lintel soffit at 2175 mm above finished floor level'.
• Mark finished floor level on every wall with a level line (often 1000 mm above FFL) before any lintel is cast, and measure every height from it.
• Keep all door shutter tops and window heads on one 2100 mm line; adjust openings in width, not height.
• Size masonry openings from the frame: shutter + gaps − rebates + frame faces + 5–10 mm fixing each side.
• Give lintels at least 150 mm bearing each side, better 200 mm or the lintel depth, and follow IS 456 for concrete grade and cover.
• In seismic zones, confirm whether a continuous lintel band (IS 4326) is required before casting individual lintels.
• Check the beam soffit before promising tall doors; above about 2300 mm the beam, not the lintel, sets the limit.
• Use three holdfasts per jamb, three hinges per 2100 mm shutter and four for main or tall doors.
• Use WPC, stone or treated frames in bathrooms and seal the bottom 100 mm of any frame in a wet area.
• Keep the false ceiling at least 300 mm above the door head, and plan lofts and curtain tracks from the lintel level.

Frequently asked questions

What is the standard lintel height from floor level in India?

The head line of doors and windows is usually 2100 mm above the finished floor, and the lintel's underside sits just above the door frame — about 2160–2175 mm for a 2100 mm shutter in a 100 × 60 mm frame. Many sites cast the lintel at 2100 mm, which works only if the frame is 2100 mm overall and the shutter is about 2030–2040 mm. Always measure from the finished floor, not the rough slab.

What is the standard door frame size in India?

The common frame section for internal doors is about 100 × 60 mm (roughly 4 × 2.5 inches), with a 12–15 mm rebate for the shutter. Main doors use heavier sections such as 125 × 65 or 125 × 75 mm. For a 900 × 2100 mm shutter, the frame measures about 1000 mm wide and 2155–2160 mm tall outside.

What should the opening size be for a 900 mm door?

About 1010–1020 mm wide and 2160–2175 mm high from finished floor level, for a 900 × 2100 mm shutter in a 100 × 60 mm frame. That allows for the shutter, 2–3 mm clearances, the rebates, the two frame faces and 5–10 mm of fixing tolerance each side.

How thick should a lintel be?

For typical residential doors and windows up to about 1.5 m wide in a 230 mm wall, an RCC lintel 150 mm deep is common; spans of 1.5–2.4 m usually need about 200–230 mm. Wider openings or openings carrying heavy loads need a lintel or beam designed by a structural engineer to IS 456.

How much bearing should a lintel have?

At least 150 mm on each side of the opening; 200 mm or the depth of the lintel, whichever is greater, is better practice. Short bearings concentrate load on the masonry at the corners of the opening and are a common cause of diagonal cracks.

Why is the bathroom door height 2000 mm?

Bye-laws derived from the National Building Code set kitchen, bath and WC doors at 0.75 × 2.0 m, and bathroom lintels in Indian construction commonly sit lower. Many designers keep one lintel level across the floor and add a fixed panel or ventilator above the 2000 mm bathroom shutter, so that the head line stays continuous.