Apartment Floor Plan: How to Read It Before Buying

For most Indian families, a flat is the largest purchase of their lives, and it is usually decided on the strength of a single sheet of paper: the floor plan in the brochure. That sheet is shown at the site office, forwarded on WhatsApp, and compared with two or three other projects over a weekend. Yet very few buyers are taught to read it. They look at the number of bedrooms, the total area and the rendering on the cover, and they sign. The disappointments arrive at possession: a bedroom where the wardrobe blocks the window, a toilet door that opens onto the dining table, a living room that is mostly corridor, a kitchen with no place for the refrigerator, or a column in the middle of the wall where the TV was meant to go.

Indian brochures make reading harder than it needs to be. Areas are quoted in three different ways, dimensions are sometimes printed as wall-centre sizes and sometimes as clear sizes, furniture is drawn smaller than real furniture, and the plan is often labelled as an artist's impression that may change. The Real Estate (Regulation and Development) Act, 2016 — RERA — has improved disclosure considerably by fixing a single definition of carpet area and requiring projects to be registered, but the buyer still has to do the reading.

This article is a practical method for reading an apartment floor plan before buying, written from the point of view of designers who spend their working lives turning such plans into homes. It is general information to help a family ask better questions; it is not legal or financial advice, and documents should always be checked with a qualified advocate before signing.

Three areas on one brochure: carpet, built-up and super built-up

Before reading a single room, settle the area. Indian flats are described by three different areas, and confusing them is the most expensive mistake a buyer can make. Carpet area is the usable floor inside the flat. RERA defines it, in Section 2(k) of the Act, as the net usable floor area of an apartment, excluding the area covered by the external walls, areas under service shafts, the exclusive balcony or verandah area and the exclusive open terrace area, but including the area covered by the internal partition walls of the apartment. Built-up area adds the external walls and, in common usage, the balcony. Super built-up area — sometimes called saleable area — adds a proportionate share of the building's common areas: staircases, lift lobbies, corridors, the entrance lobby, and sometimes the clubhouse and other amenities.

The difference between carpet and super built-up area is called loading. It varies widely by project: a simple mid-rise building with one staircase and a short corridor may carry modest loading, while a tower with large lobbies, refuge areas and a clubhouse may carry a great deal. Figures of roughly 20–40 per cent are commonly met in Indian cities, and in some large gated communities more. Because loading differs so much, two flats that are both called 1,350 sq ft can contain very different homes.

A worked example of price per square foot

Suppose a project quotes ₹5,500 per sq ft on a super built-up area of 1,350 sq ft. The agreement value is about ₹74.25 lakh before taxes, parking and other charges. If the RERA carpet area is 1,000 sq ft, the family is really paying about ₹7,425 per sq ft of usable floor. A second project quoting ₹6,200 per sq ft on 1,200 sq ft super built-up — about ₹74.4 lakh — may look more expensive per square foot, but if its carpet area is 1,020 sq ft, its real price is about ₹7,294 per sq ft of carpet, and it is actually the better buy on area. These figures are illustrative arithmetic, not market rates; the method is what matters. The same rule applies after possession: interior rates are always applied to carpet area, never to super built-up area.

Reading the drawing: scale, symbols and dimensions

A floor plan is a horizontal slice through the flat at roughly one metre above the floor, looked at from above. Everything cut by that slice — walls, columns, window frames — is drawn as a solid or heavy line; everything below it, such as the floor pattern, the kitchen platform and the sanitary fittings, is drawn in thinner lines; and things above it, such as beams and lofts, are drawn dashed. Architectural drawing practice in India follows IS 962, the Bureau of Indian Standards code of practice for architectural and building drawings, and most builder plans use the conventions shown below even when they simplify them for marketing.

Dimensions deserve the most care. Builder plans in India are usually printed in feet and inches, sometimes in millimetres, and occasionally in both. A label such as 11'0" × 13'6" may be the clear size from finished wall to finished wall, or it may be measured to the centre of the walls, which can make every room look 100–230 mm larger than it really is. Some plans give sizes before plaster; plaster takes away another 12–20 mm on each face. Ask the sales team in writing whether the printed sizes are clear internal sizes, and check one or two rooms with a tape at a sample flat or at the shell stage if possible.

Check every room: legal minimum, comfortable size and the furniture test

The National Building Code of India 2016, Part 3, and the local development control regulations set minimum sizes for habitable rooms. The commonly applied NBC figures are about 9.5 m² for the main habitable room with a minimum width of 2.4 m, 7.5 m² for a second habitable room with 2.1 m width, 5.0 m² for a kitchen, 1.8 m² for a bathroom, 1.1 m² for a WC and 2.8 m² for a combined bath and WC, with a habitable-room height of 2.75 m. These are minimums for approval, not comfort targets. A plan that only meets them will feel tight to most Indian families, and a room that meets the area but not the width will not take a bed and a wardrobe side by side.

The furniture test is the single most useful habit a buyer can learn. Take the clear room size and draw real furniture into it at real size: a king bed is about 1800 × 2000 mm (with frame, closer to 1950 × 2150 mm), a queen bed about 1500 × 2000 mm, a wardrobe needs 600 mm of depth plus about 900 mm in front to open shutters and stand, a three-seater sofa is 2000–2200 mm long and 850–950 mm deep, and a six-seater dining table is about 1800 × 900 mm with 900 mm of chair pull-out on every side used. Brochure furniture is almost always drawn smaller than this. If real furniture fits with 600–750 mm walking space around the bed and the doors still open fully, the room works.

Circulation, zoning and privacy

Once each room passes, read the plan as a sequence of movements. Start at the main door and walk through the flat with a pencil. A good plan has a small foyer or at least a shoe-and-key wall so the door does not open straight into the sofa. From the entrance, the living room should be visible, but the bedrooms, the toilets and ideally the kitchen working area should not. The dining area should sit close to the kitchen. Bedrooms should be grouped off a short passage, away from the entrance. Toilet doors should open into a bedroom or a passage, never directly onto the dining table or the living sofa.

Circulation also has a cost. Every square metre of passage is paid for at the same rate as a bedroom. A practical check is to add up all the space that exists only to move through — passages, the strip in front of doors, the route across the living room between the entrance and the bedrooms — and compare it with the carpet area. Plans where passages exceed roughly a tenth of the carpet area are usually inefficient, and a plan with a slightly smaller carpet area but almost no passage can be the better home. Look also for doors that clash: two doors swinging into the same corner, a wardrobe shutter that hits a door, or a balcony door that opens against a sofa.

Privacy in Indian family life

Indian homes have particular privacy needs that are easy to test on paper. Guests are received in the living room, so the master bedroom door should not be in the guest's line of sight. Elders often prefer a bedroom near the living area and a common toilet; children's rooms benefit from being away from the TV wall. The pooja space, where planned, needs a quiet wall not shared with a toilet. And in many families the kitchen is a working space that should not be on display from the sofa, so a kitchen opening directly onto the living room without a door or screen may suit some households and not others. None of this is visible in a rendering; all of it is visible on the plan.

Light, ventilation and orientation

A floor plan without a north arrow cannot be judged for comfort. In most of India, and especially in hot-humid Gujarat cities such as Surat, the orientation of the main living spaces decides how hot the flat will feel. West-facing glass receives the low, hot afternoon sun, and a living room with a large west window will often need curtains drawn all afternoon. North light is steady and glare-free. South walls receive strong sun but at a high angle that is easier to shade with a balcony or a chajja. The prevailing breeze in many coastal Gujarat cities comes broadly from the south-west during the monsoon, so windows on two opposite or adjacent walls help to pull air through.

NBC 2016 sets a widely used rule for daylight and ventilation: the aggregate area of openings in habitable rooms and kitchens, excluding doors, should be not less than one-tenth of the floor area, and no part of a habitable room should be too far from a window. That rule is a minimum. A bedroom of 3000 × 3600 mm has 10.8 m² of floor, so it needs at least about 1.08 m² of window — a 1200 × 1200 mm window gives 1.44 m² and passes comfortably. A bedroom whose only window opens into a narrow duct or a deep recessed balcony may pass on paper and still be dark.

Structure and services: what can never move

Many families plan to change a flat after possession — merge a bedroom with the living room, enlarge a kitchen, convert a balcony, move a toilet. The plan tells you in advance which changes are possible. In a typical RCC framed building, columns, beams and shear walls carry the building and can never be removed or cut. In some modern towers built with aluminium formwork, most walls are load-bearing RCC walls, which means almost no wall can be broken; the plan usually shows these walls drawn thicker or hatched. Non-structural infill walls of brick or AAC can often be altered, subject to the society's rules and, where needed, a structural engineer's confirmation.

Wet areas are the second fixed element. Toilets and kitchens connect to vertical shafts that run through all floors, and their floors are often sunk to carry pipes. Moving a toilet far from its shaft means raised floors, long slopes for drains and a high risk of leakage into the flat below. Over every bedroom there should ideally be another bedroom, not a toilet; stacking matters for leaks and noise. Check, too, where the AC outdoor units will sit, where the kitchen exhaust will discharge, where the water purifier and washing machine will go, and whether the electrical distribution board sits behind the main door, which is common and acceptable, or in the middle of a bedroom wall, which is not.

Documents: what the brochure plan should match

A brochure plan is a marketing document. The plans that matter are the ones approved by the planning authority and the ones registered with the state RERA authority and attached to the agreement. Under RERA, a project must be registered before it is marketed, and its registration on the state RERA website typically shows the project details, the sanctioned plans and the carpet area of the apartment types. The agreement for sale should state the carpet area of the specific flat and attach its floor plan. Read these documents side by side with the brochure, and if anything differs — a room size, a window, a balcony, a column — ask which one governs. This is general information, not legal advice; a family should have the agreement reviewed by a qualified advocate before signing.

Comparing two or three projects fairly

When a family shortlists flats in different projects, the floor plans should be compared on the same basis. Convert each to RERA carpet area. Divide the total cost — including parking, development charges and other compulsory payments — by that carpet area. Then score each plan on the five passes in this article: area honesty, furniture fit, circulation and privacy, light and orientation, and fixed structure and services. A plan with 5 per cent less carpet area but a clean zoning, cross-ventilation in every bedroom and no column in the living room is usually the better home for the next twenty years.

Bring a printed copy of each plan, a scale ruler or a simple grid overlay, and a list of your largest furniture. Draw your own furniture on each plan with a pencil. Mark the north arrow, the west wall and the windows. Circle every column. Highlight passages in one colour. Within ten minutes, the differences between projects that looked identical in the brochure become obvious.

Where apartment floor plans are heading

Three changes are visible in Indian housing. First, disclosure is improving: RERA has made carpet area the common language, and many developers now provide dimensioned plans, 3D walkthroughs and sample flats that let buyers test rooms at true size. Second, plans are getting more compact and more flexible: smaller flats with fewer passages, convertible study rooms, larger balconies and kitchens designed for appliances rather than just a platform. Third, digital tools are spreading: virtual tours, digital twins of buildings and furniture-planning apps let a family place real furniture into a plan before booking. The tools will change; the reading method will not. A plan still has to fit real furniture, real families, real sun and a structure that cannot move.

Ten rules for reading a floor plan before booking

• Compare every flat on RERA carpet area, and divide the full cost by that carpet area.
• Ask in writing whether printed room sizes are clear internal sizes or centre-line sizes.
• Draw your own largest furniture at true size into every room before deciding.
• Check that each bedroom has a wall at least 2400–3000 mm long without a door or window, for a wardrobe or bed.
• Trace the walk from the main door: no toilet door on the dining table, no bedroom in the guest's line of sight.
• Add up passage space; be wary when it exceeds about a tenth of the carpet area.
• Find the north arrow; avoid large unshaded west glass in the living room and main bedroom.
• Look for windows on two walls in at least the living room and the main bedroom.
• Circle every column and beam, and confirm which walls are RCC before planning any change.
• Match the brochure plan with the RERA registration, the sanctioned plan and the plan attached to the agreement.

Frequently asked questions

What is the difference between carpet area and super built-up area?

Carpet area, as defined under RERA, is the usable floor inside the flat including internal partition walls, but excluding external walls, service shafts and exclusive balconies or terraces. Super built-up area adds the external walls, balconies and a share of the building's common areas such as lobbies, staircases and lifts. The difference is called loading and is commonly 20–40 per cent.

How do I know if room sizes on a brochure are accurate?

Ask the developer in writing whether sizes are clear internal dimensions after plaster or centre-line dimensions. Compare the brochure with the plan attached to the agreement and the RERA-registered plans, and measure a sample flat or a flat at shell stage where possible. Centre-line sizes can make a room appear 100–230 mm larger in each direction.

What is a good carpet area for a 2BHK or 3BHK?

In Indian cities, a compact 2BHK commonly has about 550–750 sq ft of carpet area and a comfortable 3BHK about 1,000–1,400 sq ft, depending on the city and the segment. Rather than chasing a number, check that each room passes the furniture test and that passages are short.

Which direction is best for a flat?

From a climate point of view, living rooms and bedrooms with north or east-facing windows, or south-facing windows shaded by a balcony, are usually more comfortable than large unshaded west-facing glass in hot Indian cities. Vastu preferences are a personal choice; many families balance them with light, ventilation and view rather than treating any single direction as essential.

Can I remove a wall in my flat after possession?

Only if it is a non-structural infill wall, the society and local rules allow it, and a structural engineer confirms it. Columns, beams, shear walls and the RCC walls of aluminium-formwork towers can never be removed. Check the plan before booking if a future change matters to you.