You can get a sound early budget in an evening with a plan, a calculator and the method below.
Step by Step
1. Built-up area. Measure each floor to the outside of external walls. Add the stair, balconies and headroom as your contractor would count them.
2. Building cost. Built-up area × per sq ft rate for your finish level.
3. Extras. Add 10–20% for items the rate leaves out.
4. Contingency. Add 10%.
5. Interiors. Price separately.
6. Check materials. Use thumb rules to estimate the biggest material lines.
Worked Example: G+1 on a 200 sq yd Plot
| Step | Calculation | Amount |
|---|---|---|
| Built-up area | 1,200 + 1,200 sq ft | 2,400 sq ft |
| Building (standard) | 2,400 × ₹2,200 | ₹52.8 lakh |
| Extras (15%) | 0.15 × 52.8 | ₹7.9 lakh |
| Contingency (10%) | 0.10 × 60.7 | ₹6.1 lakh |
| Total before interiors | ≈ ₹66.8 lakh |
Material Check (2,400 sq ft)
| Material | Thumb rule | Quantity |
|---|---|---|
| Cement | 0.4 bag / sq ft | ~960 bags |
| Steel | 3.5 – 4.5 kg / sq ft | 8.4 – 10.8 t |
| Sand | 1.8 cft / sq ft | ~4,300 cft |
| Aggregate | 1.35 cft / sq ft | ~3,240 cft |
Price these at today's rates to see the share of the budget they represent, and how much better buying could save.
The Short Version
Built-up area × rate, plus 10–20% extras, plus 10% contingency, interiors separate. It is an early budget; a priced BOQ makes it a firm one.
