Quoting a Bathroom Re-Pipe with Waste, Overhead, and Contingency
Prepare a quotation for replacing the cold-water distribution in two back-to-back bathrooms. The existing 15 mm GI is being replaced with CPVC. Take-off: 22 mm pipe 24 m at ₹190/m; 15 mm pipe 36 m at ₹120/m; elbows, tees, and fittings as a lump sum at ₹6,200; PTFE tape and solvent cement ₹450; a new 20 mm gate valve at ₹1,100. Labour: one plumber at ₹1,000/day and one helper at ₹650/day for 4 days. Allow 8% waste on pipe and fittings. Overhead is 10% of material plus labour; profit is 12% of the subtotal including overhead. A 5% VAT applies to the final invoice. The client wants a fixed price and asks for a 10% contingency because walls will be opened. Both bathrooms remain in use at night, so work is restricted to 8 hours per day.
1. Calculate the material cost, including waste, showing the waste base clearly.
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Waste applies to pipe and fittings, not to consumables. Waste base: 22 mm pipe 24 × ₹190 = ₹4,560; 15 mm pipe 36 × ₹120 = ₹4,320; fittings ₹6,200; gate valve ₹1,100. Total waste base = ₹4,560 + ₹4,320 + ₹6,200 + ₹1,100 = ₹16,180. Waste at 8% = ₹1,294.40. Consumables ₹450 carry no waste. Material cost = ₹16,180 + ₹1,294.40 + ₹450 = ₹17,924.40. Round to ₹17,924 if quoting in whole rupees, but keep the calculation visible so the client can see that the gate valve and fittings are included.
2. Calculate labour, overhead, profit, VAT, and the final invoice amount.
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Labour: plumber 4 × ₹1,000 = ₹4,000; helper 4 × ₹650 = ₹2,600; total labour = ₹6,600. Material plus labour = ₹17,924.40 + ₹6,600 = ₹24,524.40. Overhead at 10% = ₹2,452.44. Subtotal including overhead = ₹26,976.84. Profit at 12% = ₹3,237.22. Amount before VAT = ₹30,214.06. VAT at 5% = ₹1,510.70. Final invoice = ₹31,724.76, say ₹31,725. Show each line separately; do not apply profit to the VAT.
3. Advise the client on the 10% contingency and explain the risk of quoting a fixed price without qualifications.
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The 10% contingency should be a separate provisional sum, not hidden inside the fixed price. If it is built into the price, the client pays it even if no extra work is needed, and the quote may look inflated. Quote a firm price for the defined re-pipe, then list a provisional sum, for example ₹2,500, for unforeseen wall opening and making good, to be reconciled with receipts. If the client insists on a truly fixed price, add a disclosed risk allowance for unknown wall construction and pipe condition. Also state exclusions: plaster repair, painting, tile replacement, and after-hours work. The 8% waste covers normal pipe offcuts, not broken tiles or hidden defects. A clear qualification protects both parties and avoids disputes when old GI is found corroded inside the wall.