A 4 BHK topping out at 2,100 sq ft, as reported at Northern Lights by Puravankara, is compact for four bedrooms. Some buyers read that as a project cutting corners. Often it is the opposite — an efficiency-led plan can deliver more usable room per rupee than a larger one, and the way to tell is to stop comparing advertised sizes.
Key takeaways
- Advertised size is super built-up. Carpet area is what you live in.
- The ratio between them, the loading factor, varies materially between projects.
- An efficient plan wastes less on corridors, dead space and awkward geometry.
- Compact plans cost less to furnish, cool and maintain, permanently.
- Compare carpet area per bedroom, not headline square footage.
The example: Northern Lights by Puravankara — 2, 3 and 4 BHK reported from 1,010 to 2,100 sq ft. Full configuration table on the listing page.
Why advertised size tells you so little
Almost every Indian project advertises super built-up area, which is your carpet area plus a share of common space — lobbies, corridors, staircases, lift shafts, sometimes amenity areas.
The proportion added is the loading factor, and it is not standardised. One project may load 25%, another 40%, and both advertise the result as the apartment’s size.
So two apartments both advertised at 2,100 sq ft can differ by several hundred square feet of space you can actually stand in. That is not a small difference; it is a bedroom.
This is precisely why the RERA framework requires carpet area to be disclosed. It is defined, it is comparable, and it is the number on which you should base every comparison.
Ask for it in writing for the exact unit, from the filing’s schedule rather than from a brochure — see how to read a RERA filing.
What an efficient plan actually does
Within the apartment, efficiency is about how much of the carpet area is usable room rather than circulation and awkwardness.
Short internal circulation. A plan where bedrooms open off a compact hall wastes far less than one with a long internal corridor. Corridors are carpet area you pay for and cannot furnish.
Regular room shapes. Rectangles furnish efficiently. Angled corners, deep recesses and odd projections look interesting on a drawing and are dead space in practice.
Sensible door and window placement. A bedroom with a door, a window and a wardrobe wall in the wrong relationship loses a usable wall, which is often the difference between fitting a bed comfortably or not.
Combined rather than duplicated space. A single well-proportioned living-dining room usually works better than two small rooms totalling the same area.
A 2,100 sq ft 4 BHK designed this way can be more comfortable than a 2,500 sq ft one that is not, and it costs less to buy, furnish, cool and maintain.
The ongoing cost nobody models
Size is not only a purchase cost. It is a recurring one, and over a long ownership the difference compounds.
| Cost | How it scales with size |
|---|---|
| Maintenance | Per sq ft, every month, forever |
| Property tax | Area-linked |
| Cooling | Roughly with volume |
| Furnishing | Roughly with area, and again at replacement |
| Painting and upkeep | With area, on a cycle |
Four hundred square feet of difference between two 4 BHKs is a meaningful monthly figure once maintenance, tax and cooling are added, and it recurs for as long as you own the home.
Work it across ten years before deciding the larger plan is obviously better. Our guide to CAM, corpus and sinking fund shows how to get the projected rate.
Interiors are the cost people underestimate most. Flooring, wardrobes, kitchen and lighting all scale with area, and they are paid again at replacement in fifteen years.
The difference between fitting out 2,100 and 2,500 square feet to the same standard is a substantial sum on day one, and it is a sum that comes out of the same budget as the purchase.
So when comparing two homes, add an interiors estimate to each before deciding which is affordable. Buyers routinely stretch on the purchase and then furnish the larger home badly, which is the worst of both.
How to compare two plans properly
Six steps, done with the dimensioned floor plans in front of you rather than the brochure renders.
- Get carpet area for both, from the RERA schedule.
- Calculate the loading factor — super built-up divided by carpet. Lower is more efficient.
- Divide carpet area by bedroom count for a rough comfort comparison.
- Measure the main bedroom and living room on the plan. Those two rooms decide how a home feels.
- Look for internal corridors and count how much area they take.
- Check each bedroom has a usable wall for a wardrobe that is not blocked by a door swing.
Step two is the one that surprises people. A project loading 1.25 is giving you materially more home at the same advertised size than one loading 1.40, and that ratio is rarely volunteered.
Step six sounds trivial and is not. A bedroom where the wardrobe cannot go against the best wall is a room you will be mildly annoyed by for twenty years.
If you can, walk a completed apartment of the same plan rather than a show flat. Show flats are frequently furnished with undersized furniture and sometimes without a wall or two, which makes any plan look generous.
When bigger genuinely is better
Being fair to the other side, because efficiency is not the only virtue and this can be taken too far.
Large households need rooms, not efficiency. If five people live there, a compact plan optimised for three will feel tight however well drawn.
Generous rooms feel different. There is a quality to a well-proportioned large living room that no amount of efficient planning replicates, and some buyers value it highly.
Premium positioning follows size. In the upper segment, larger formats hold value partly because scarcity and status attach to them.
So the honest advice is neither “buy compact” nor “buy large”. It is: compare carpet area rather than advertised size, look at the plan rather than the number, and buy the one that works for how your household actually lives.
Our guides to what add-on rooms really cost and what the half in a 2.5 BHK actually is cover the same question at the configuration level.
Common questions
Why do advertised apartment sizes differ from usable space?
Because most projects advertise super built-up area, which adds a share of common space to your carpet area. The proportion added, the loading factor, is not standardised, so two apartments advertised at the same size can differ by hundreds of usable square feet.
What is a loading factor and what is good?
Super built-up area divided by carpet area. A lower ratio means more of what you pay for is space you can stand in. A project loading 1.25 gives materially more home at the same advertised size than one loading 1.40.
Is a compact 4 BHK worse than a larger one?
Not necessarily. An efficiently planned 2,100 sq ft four-bedroom can be more comfortable than a poorly planned 2,500 sq ft one, and it costs less to buy, furnish, cool and maintain. Compare carpet area and the actual plan rather than headline size.
What makes an apartment plan efficient?
Short internal circulation rather than long corridors, regular rectangular room shapes, sensible door and window placement that leaves usable walls, and combined well-proportioned living space rather than duplicated small rooms.
How do I compare two floor plans properly?
Get carpet area for both from the RERA schedule, calculate each loading factor, divide carpet area by bedroom count, measure the main bedroom and living room on the plan, count area lost to corridors, and check each bedroom has a usable wardrobe wall.
Comparing two floor plans?
Send us both and we will work out carpet area, loading factor, area lost to circulation and usable wall in each bedroom. It is the comparison the brochure does not let you make. No charge.
Related reading
Figures above are drawn from published project information and are indicative. Verify any registration yourself on the Karnataka RERA portal before paying a booking amount.
