Duplex house plan (G+1)
A duplex — ground plus one, used by a single family — is how most Indian plots under 1500 sq ft get a three or four bedroom house. The whole design comes down to two questions: what goes upstairs, and where the staircase lands.
Splitting the floors
| Ground floor | First floor |
|---|---|
| Living / hall | Family lounge or upper living |
| Kitchen and dining | Two bedrooms with attached toilets |
| One bedroom (for elders) | Balcony over the porch |
| Common toilet | Terrace access |
| Pooja, utility, car porch | Study / home office |
Put a bedroom on the ground floor
Almost every duplex that gets regretted is one where all bedrooms went upstairs. Elderly parents, a guest, someone recovering from surgery, or simply you in twenty years — one ground-floor bedroom with a toilet next to it is the most useful room in a duplex, and the easiest one to design out by accident.
Staircase sizing and placement
- A comfortable dog-leg stair needs about 8 × 10 ft including the landing. A straight flight needs about 3.5 × 14 ft.
- Riser 6 to 6.5 inches, tread 10 to 11 inches. Sixteen to eighteen risers for a 10 ft floor-to-floor height.
- Vastu puts the stair in the south, south-west or west, turning clockwise as you go up. Keep it out of the centre and the north-east.
- Stack it over the utility or the store, not over the living room, so the underside is useful.
- A skylight over the stairwell lights the middle of both floors — the single highest-value 20 sq ft in a deep plan.
Stacking services
Put the first-floor toilets directly above the ground-floor toilets, and the kitchen below the utility rather than below a bedroom. One plumbing shaft instead of three is worth more than any finish you will choose.
Frequently asked questions
What is a duplex house?
In Indian usage, a duplex is a single home spread over two floors connected by an internal staircase — usually ground plus first. It is different from the American sense of the word, which means two separate dwellings.
How much space does a staircase need?
About 8 × 10 ft for a dog-leg stair with a landing, or roughly 3.5 × 14 ft for a straight flight. Budget 50–90 sq ft on each floor.
Is a duplex cheaper than a single floor house of the same area?
Usually yes, per square foot — you pay for one foundation and one roof instead of spreading both over a larger footprint. You also use less land, which on a city plot is the expensive part.