Estimates, Worked Examples and Checklists
Apartment façade repainting cost per flat: how a society splits the bill
Worked example of measuring and pricing exterior repainting for an apartment building in India and splitting the cost per flat by area or equally, with GST and retention.
For an apartment building, exterior repainting is measured on the whole building's wall area, priced per sq ft with scaffolding or rope access as a lump sum, and then divided among the flats according to the society's bye-laws: usually either in proportion to each flat's area or equally per flat. In the illustrative example below, a 4-storey, 16-flat building with about 14,000 sq ft of exterior wall comes to roughly ₹6.9 lakh including GST, which is about ₹43,000 per flat if shared equally, or between about ₹36,000 and ₹50,000 if shared by area.
Part of how to read a roofing or façade quotation.
The building
- Ground + 3 upper floors, 4 flats per floor, 16 flats in all
- Building footprint about 60 ft × 50 ft; floor-to-floor height 10 ft, plus a 3 ft parapet
- Two flat sizes: 8 flats of 900 sq ft and 8 flats of 1,250 sq ft (carpet or built-up area as recorded by the society)
Step 1: measure the wall area
- Perimeter: 2 × (60 + 50) = 220 ft
- Height: 4 floors × 10 ft + 3 ft parapet = 43 ft
- Gross elevation: 220 × 43 = 9,460 sq ft
- Deduct windows and doors: say 1,600 sq ft
- Add window reveals, chajjas, balcony faces, staircase shaft, mumty and parapet inner face: say 6,140 sq ft
- Wall area to paint: 9,460 − 1,600 + 6,140 = 14,000 sq ft
In real buildings balconies, ducts and projections can add a lot. Ask the contractor to measure with you, face by face, and to state the method in the contract. See exterior painting cost per sq ft for measurement methods.
Step 2: price the work
| Item | Basis (illustrative) | Amount |
|---|---|---|
| Washing, fungicidal wash, scraping | 14,000 × ₹4 | ₹56,000 |
| Crack repair, hollow plaster repair | Lump sum after inspection | ₹60,000 |
| Primer + 2 coats exterior emulsion | 14,000 × ₹26 | ₹3,64,000 |
| Scaffolding, 43 ft high, full building | Lump sum | ₹80,000 |
| Debris removal, protection of cars and plants | Lump sum | ₹25,000 |
| Subtotal | ₹5,85,000 | |
| GST 18% | ₹1,05,300 | |
| Total | ₹6,90,300 |
Step 3: split the cost among the flats
Method 1: equally per flat
₹6,90,300 ÷ 16 = ₹43,144 per flat (rounded).
Method 2: in proportion to area
- Total area: 8 × 900 + 8 × 1,250 = 7,200 + 10,000 = 17,200 sq ft
- Cost per sq ft of flat area: 6,90,300 ÷ 17,200 ≈ ₹40.134
- 900 sq ft flat: 900 × 40.134 ≈ ₹36,120
- 1,250 sq ft flat: 1,250 × 40.134 ≈ ₹50,167
- Check: 8 × 36,120 + 8 × 50,167 = 2,88,960 + 4,01,336 = ₹6,90,296, the small difference being rounding.
Which method applies is set by the society's bye-laws or a general body resolution, not by the committee's preference on the day. See society and RWA rules for façade and terrace work.
Step 4: use the repair fund first
If the society has a repair or sinking fund that can be used for this work, the contribution per flat falls. For example, if ₹2,00,000 is available from the fund:
- Remaining: 6,90,300 − 2,00,000 = ₹4,90,300
- Equal share: 4,90,300 ÷ 16 ≈ ₹30,644 per flat
Step 5: payment stages and retention
A society contract of this size benefits from stages and retention.
| Stage | Share (illustrative) | Amount |
|---|---|---|
| Mobilisation and scaffolding | 20% | ₹1,38,060 |
| Preparation and primer complete | 30% | ₹2,07,090 |
| Final coats complete, scaffolding removed | 40% | ₹2,76,120 |
| Retention after the next monsoon | 10% | ₹69,030 |
Check the stage arithmetic with the retention and payment calculator. Hold retention until the committee has inspected for peeling, blistering and patchiness after heavy rain.
Points committees often miss
- Terrace and façade together. If the terrace also leaks, doing both while scaffolding is up can save one access cost. See the terrace waterproofing worked example.
- Individual changes. Flats with their own grills, enclosures or AC brackets: decide in advance who moves and refits them.
- Colour approval. Record the chosen colour and shade code in the minutes and the contract.
- Safety at height. The contractor should be responsible for workers' safety equipment and for insurance against accidents and third-party damage.
- Records. Keep the quotations, comparison sheet, resolution, contract, invoices and warranty in the society's file.
FAQ
Can a member refuse to pay because their flat's walls are fine?
External walls are usually common property, so the cost is shared under the bye-laws. Disputes over the method of sharing go to the society's general body and, for co-operative societies, to the dispute forum under the state act.
Should the society pay GST?
If the contractor is registered and supplies the paint, GST at 18% is generally charged on the contract value. Make sure the invoice is in the society's name.
Is a cheaper painter without GST better?
The contractor's registration status should not be the deciding factor. Compare scope, preparation, safety arrangements, supervision and warranty. A contractor below the GST threshold may be fine for a small job but may not have the capacity for a 4-storey building.
How long should the repaint last?
It depends on the paint grade, preparation and exposure. Ask for the warranty terms in writing.
Sources and where to check
- Your state's registrar of co-operative societies — model bye-laws and disputes (search your state government portal)
- CBIC GST portal — GST on works contracts
- National Consumer Helpline — if the contractor does not honour the contract
