Carpet, Built-Up, Super Built-Up and UDS: Reading a Chennai Price Sheet

A 1,200 square foot flat is not a fact. It is a claim, and it depends on which 1,200 square feet somebody is talking about. In Chennai, the same flat can be described in four different areas on four different pages of the same brochure, and the biggest number usually gets the largest font.

Think of it as a room that is there on paper yet missing from the floor. Every buyer has met it. Most have paid for it.

This note explains the four measures, shows you how to compare two projects on the measure that matters, and walks through the lines of a cost sheet that turn a per-square-foot rate into what you will actually pay. It also explains a fifth measure, the undivided share of land, which Chennai cares about more than most cities do, and for good reason.

Carpet area: the floor you can actually use

Carpet area is the one RERA defined, precisely so that buyers would have a measure nobody could stretch. Under the Act, it is the net usable floor area of an apartment, excluding the area covered by the external walls, the areas under service shafts, and any exclusive balcony, verandah or open terrace, but including the area covered by the internal partition walls.

In plain terms: it is the floor inside your front door that you can walk on, plus the thickness of the walls between your own rooms. Nothing outside your front door counts. Nothing you cannot stand on counts.

A registered project has to state the carpet area of each apartment type in its registration, and the agreement for sale has to state the carpet area of your apartment. That makes carpet area the one number you can verify on the TNRERA project page before you sign anything. Start every comparison here.

Built-up area: the carpet plus the walls

Built-up area adds the thickness of the external walls to the carpet area, and usually the area of balconies and other spaces exclusive to the unit. In Chennai you will also hear "plinth area", which is used in much the same sense.

The gap between carpet and built-up is real and fairly predictable. Walls have thickness; balconies are genuinely yours. Nobody is being tricked here.

Super built-up area: the building's share of you

Super built-up area, often called saleable area, takes the built-up area and adds your proportionate share of the building's common spaces: the entrance lobby, corridors, staircases, lift wells, the clubhouse, sometimes the security cabin, the generator room and the terrace.

This is the number most price sheets are quoted on, and the one that grows fastest. A project with a grand double-height lobby, wide corridors and a large clubhouse has more common area to divide among its flats, so each flat's super built-up figure rises, and so does its price at the same per-square-foot rate.

The difference between super built-up and carpet is known as the loading. It is not a trick in itself – common areas are real and somebody has to pay for them – but it is where most of the confusion lives, and where two projects that look alike on a price sheet stop looking alike on the floor.

Working out the loading

Here is the arithmetic, with illustrative numbers.

A flat is quoted at 1,200 square feet super built-up. The registration shows a carpet area of 900 square feet. The loading is 300 square feet, or a quarter of what you are paying for.

A second flat, in another project, is quoted at 1,150 square feet super built-up, at a slightly higher rate. Its carpet area is 950 square feet. The loading is 200 square feet.

The second flat is smaller on the brochure, dearer per square foot, and bigger where you live. The first flat's extra 50 square feet of headline area is pure legerdemain: you will pay for it, and you will never put a sofa on it.

So convert every quote into a price per square foot of carpet area. Divide the all-inclusive price by the carpet area from the registration. That is the only number that compares like with like.

When a higher loading is worth it

None of this means the project with the lowest loading always wins. Common areas buy you things.

More lifts for the number of flats, which matters every morning at 8.45.

Wider corridors and a lobby that does not feel like a lift shaft with a sofa in it.

A clubhouse, a gym and a pool that you will actually use, rather than admire in the brochure.

Staircases, fire exits and service areas built to a standard that will still feel safe in twenty years.

So the question is not whether the loading is low. It is whether the common areas you are paying for are ones you want, in a size that makes sense for the building. A loading that buys a well-run clubhouse in a community of five hundred families is a different thing from one that buys a grand lobby in a building of forty. Ask what is in the common area, and then decide whether it is worth your share.

UDS: the land beneath your flat

Now the measure that makes Chennai different.

The undivided share of land, or UDS, is the portion of the plot that belongs to you. It is undivided because nobody owns a particular square of ground; each owner holds a share of the whole. It is usually worked out in proportion to each flat's area: a flat that accounts for 1 per cent of the building's total saleable area holds roughly 1 per cent of the land.

Why should a buyer care about a share of ground they cannot fence? Three reasons.

Land holds value; buildings age. Thirty years from now, the concrete will be thirty years old and the land will be land. When older apartment buildings in the city are redeveloped, it is the owners' undivided shares that the developer is really negotiating for.

UDS measures density. Two projects of the same flat sizes, one with a generous UDS per flat and one with a thin one, are telling you how many families are sharing the same ground. More land per flat usually means more open space, fewer people per lift and a quieter building.

UDS is registered. In Tamil Nadu, apartment purchases have long been documented in two parts: a sale deed for the undivided share of land, and a construction agreement for the building. How each part is stamped and registered has changed more than once in recent years, so let your lawyer confirm the current position. What does not change is that your UDS should be stated in your documents, and you should check it.

Take a hypothetical buyer, Divya, comparing two three-bedroom flats in Medavakkam of almost identical carpet area. One building stands on a plot that gives each flat about 400 square feet of UDS; the other, a taller tower on a tighter plot, gives each about 250. Same flat. Very different stake in the ground.

Balconies, utilities and the spaces in between

Some areas sit in an awkward middle. They are yours, but they are not carpet.

An exclusive balcony or verandah is excluded from carpet area by definition, and is disclosed separately in the registration. It is real, usable space, and worth paying for. But it should be priced and described as a balcony, not quietly folded into a single headline figure.

A utility area off the kitchen, a dry balcony for the washing machine, a duct or a shaft running through the flat: check how each is counted. A service shaft is excluded from carpet area; a utility room inside your walls is not.

An open terrace attached to a penthouse is excluded from carpet area too, and sold at its own rate. Ask what that rate is, and whether the terrace is exclusive to you in the documents or merely accessible from your door.

And car parking is not area at all. It is a separate right, priced separately, and it should be allotted to you by number in writing.

Measuring at handover

When the flat is finally yours to inspect, take a laser measure and the floor plan from your agreement. Measure each room wall to wall, add up the internal areas, and compare the total with the carpet area you agreed. The figure will rarely match to the square foot, because walls and finishes take their share, but it should be close. If it is not, the agreement's clause on variation in area is the one to read next, and the time to raise it is before you sign the handover letter, not after.

What is on a cost sheet

A per-square-foot rate is where a cost sheet starts, not where it ends. Here are the lines you will meet in Chennai, roughly in the order they appear.

Basic price: the rate multiplied by the area it is quoted on, which is usually super built-up.

Floor rise: an additional charge per square foot for each floor above a certain level.

Preferential location charges: for a corner unit, a park view, a sea view or an east-facing door.

Car parking: covered or open, priced per slot.

Amenities or clubhouse charges: a contribution to the common facilities.

Corpus fund: a one-time deposit that funds the association's reserve.

Maintenance deposit: advance maintenance, often for one or two years.

Electricity, water and sewage connection charges: deposits and infrastructure contributions for the services.

Legal and documentation charges.

GST: on under-construction property, and not on a completed one. Whether that tilts the decision is one of the questions in under construction or ready to move.

Stamp duty and registration: paid at registration, on the higher of the guideline value and the price in the deed.

Add the lines that are certain, and you arrive at the all-inclusive price. Ask for it in writing. A cost sheet that will not show you the total is a cost sheet that does not want you to see it.

What to ask the sales team

What is the carpet area of this unit, as registered with TNRERA?

On which area is the rate quoted?

What is included in the common area loading, and what is the total common area of the project?

What is the undivided share of land for this unit?

What is the all-inclusive price, and which lines in it are estimates?

If the delivered carpet area differs from the agreed one, what happens? Many agreements set a small tolerance and say what is refunded or charged beyond it. Read that clause.

In the resale market

All of this applies with extra force to resale. An older building may have been sold in the days before RERA, with only a super built-up area on the documents and a loading that nobody remembers agreeing to. Measure the flat yourself, read the UDS off the original sale deed, and price it on carpet area like any other. We cover the rest of the resale checklist in buying a resale flat in Chennai.

Where this matters most

Loading and UDS vary most in the large new communities, where clubhouses are big and towers are tall. Compare carefully if you are looking at two-bedroom or three-bedroom flats along OMR around Sholinganallur, or in the busy southern suburbs around Medavakkam and Pallikaranai. If you are still deciding between the two big southern roads, OMR or GST Road is a good place to start.

Measure twice, buy once

A flat is the floor you walk on, the walls around it, a share of the building and a share of the ground beneath. Every one of those has a price, and every one of them should be written down. The skill is not in rejecting the bigger numbers. It is in knowing which one you are being quoted.

If you have a cost sheet you would like read, send it to us. We will turn it into a price per square foot of carpet area, put the UDS beside it, and tell you what the flat really measures.