Draw your room
Three dimensions. The box redraws to scale as you type.
How this visualizer works
- Isometric projection. Each point (x, y, z) maps to screen coordinates using x' = (x − y) × cos 30° and y' = (x + y) × sin 30° − z. That is standard isometric, so parallel edges stay parallel and the scale is uniform in all three axes.
- Scale is fitted automatically to the drawing area, so a 40 ft hall and an 8 ft box room both fill the frame and can be compared by shape rather than by size.
- Two walls and a floor are drawn, with the far wall shaded to 90% of the wall tone and the floor in its own colour, so the three planes read separately.
- Furniture blocks are placed deterministically at fixed positions scaled to the room — a 7 × 2.8 ft sofa block, a 1.6 ft deep unit on the far wall, and with 'furnished' a table and a tall unit. They are massing blocks, not furniture.
- Volume = length × width × height. Cooling load is estimated at volume ÷ 130 with a 0.8 ton floor, and ventilation at four air changes per hour converted to cfm.
- The proportion note is banded, not generated: under 1.35 near-square, 1.35 to 2.2 a natural long axis, above 2.2 corridor-like.
| Ratio | Reads as | How to furnish it |
|---|---|---|
| 1.0 – 1.2 : 1 | Square | Anchor on one wall; a central float leaves four awkward corners |
| 1.2 – 1.35 : 1 | Near-square | One seating group, one secondary function |
| 1.35 – 2.2 : 1 | Natural long axis | Easiest to furnish — group along the axis, circulate past |
| 2.2 – 3.0 : 1 | Corridor-like | Break into two zones with a rug, a ceiling change or a low unit |
| Over 3.0 : 1 | Passage | Treat as circulation with function against one wall only |
Design and build under one accountable roof
Worked example — the default room
| Quantity | Arithmetic | Result |
|---|---|---|
| Floor area | 14 × 11 | 154 sq ft |
| Wall area | 2 × (14 + 11) × 10 | 500 sq ft |
| Volume | 14 × 11 × 10 | 1,540 cu ft |
| In cubic metres | 1,540 ÷ 35.3147 | 43.6 m³ |
| Indicative cooling load | 1,540 ÷ 130 | 1.2 ton |
| Ventilation at 4 ACH | 1,540 × 4 ÷ 60 | 103 cfm |
| Proportion | 14 ÷ 11 | 1.3 : 1 — near-square |
Why a box model is more useful than a render at this stage
Renders arrive late, cost money and encourage decisions about cushions before decisions about proportion. A box model arrives in a second and answers the questions that actually matter at the start: is this room long enough to take a sofa and a dining table, or will one of them end up in a corridor; is the ceiling high enough for a cove without the room feeling squashed; how much wall is there to panel, and is that a sensible amount of joinery for the budget.
The specific proportion trap in Mumbai flats is the combined living-dining. Developers often deliver a single 22 × 11 ft space, which at 2:1 sits right at the edge of corridor territory. Furnished as one room it never settles; broken into two zones — a seating group on a rug at one end, the table at the other, with a low unit or a ceiling change marking the boundary — it works. Seeing 2:1 written down is usually what prompts that decision.
The other thing the model exposes is ceiling height relative to footprint. A 9 × 8 ft box room with a 10 ft slab is a surprisingly tall volume, and it takes full-height joinery and a tall window treatment far better than people expect. Conversely a 20 × 16 ft living room with 9 ft 6 in clear height is a shallow volume, and a heavy dropped ceiling across it will make it feel lower than the number suggests.
Every constant on this page comes from Greenbox site records — measured drawings, signed BOQs and completion certificates from projects delivered between 2023 and 2026 — rounded to the figures an estimator would actually write down. We publish them so the arithmetic can be audited rather than trusted. Treat the output as a planning figure: accurate enough to brief a landlord, a bank or a family, and not accurate enough to sign a contract against.
What this tool does not cover
- Beams, columns, ducts, niches and anything else that is not a rectangular box.
- Doors and windows, which are not drawn — the model shows volume and proportion only.
- Furniture dimensions. The blocks are massing studies at fixed positions, not a layout.
- Sloped and double-height ceilings.
- The cooling load figure is a sanity check only — use the AC tonnage calculator, which accounts for orientation, glazing and occupancy.
- For a measured plan with furniture placed to scale, see the floor plan drawer and the furniture arrangement planner.
Selected work by Greenbox Design Studio. Tap any image to enlarge.
Frequently asked questions
What is a good room proportion?+
Between about 1.35:1 and 2:1 is the easiest to furnish — there is a clear long axis for a seating group and room to circulate past it. Near-square rooms are comfortable but give no obvious axis; anything over 2.2:1 starts to read as a corridor and needs to be broken into zones.
How do I calculate room volume?+
Length × width × height. A 14 × 11 ft room with a 10 ft ceiling is 1,540 cubic feet, or 43.6 cubic metres. Volume rather than floor area is what drives cooling load, ventilation and how a room sounds.
Is this a real 3D renderer?+
No, and it does not pretend to be. It is a scaled isometric box model drawn from three dimensions — deliberately simple, instant, and useful for checking proportion before any design decisions are made. For photorealistic visuals you need a modelled room with real furniture and materials.
Why is wall area so much larger than floor area?+
Because walls go up. A 14 × 11 ft room has 154 sq ft of floor and 500 sq ft of wall at a 10 ft ceiling — more than three times as much. That ratio is why painting, panelling and wall tiling always cost more than people estimate from the floor plan.
Does ceiling height affect air conditioning?+
Yes, because an AC cools air, not floor. Going from an 8 ft to a 10 ft ceiling over the same footprint adds 25% more air to condition. Most rule-of-thumb tonnage tables assume a 9 to 10 ft ceiling, so a double-height space needs a properly calculated load.