House Construction Cost Calculator for Patna & Bihar
A cost estimate that follows the law. It reads your plot and road, applies the Bihar Building Byelaws to find what you can actually build, then prices it at today's local rates, with GST, approval fee and build time.
How the estimate is built
- Byelaw check first. Your road width and plot size give the FAR, height limit and setbacks under the Bihar Building Byelaws 2014 and its October 2025 amendment. The covered area per floor is filled in from those setbacks, so you start from a buildable number. If your floors exceed what your road allows, you are told before you see a price.
- Package rate. Budget ₹1,795, Classic ₹2,045 or Premium ₹2,445 per sq.ft, including GST. These sit within Patna's 2026 market bands for economy, standard and premium construction.
- Local adjustment. Labour and local materials (about 60% of cost) are adjusted for your town. Steel and cement are priced nationally, so they don't change.
- Structure factors. A single-storey house costs about 10% more per sq.ft, because the foundation and roof are spread over less area. Seismic zone V (north Bihar) adds about 4% for extra steel and detailing.
- Parking. A stilt floor is priced at about 40% of the package rate: it has structure but no walls or finishes. A basement is priced at about 75% plus dewatering, with a wider range because soil and water table vary.
- Always included: the stair cabin (mumty) and parapet on the roof, and the 1% labour welfare cess required by law.
- The result is a range. Real projects vary with soil, design and market prices, so you see low, likely and high values, not one exact figure.
Construction cost in Patna, 2026
| Item | Patna rate (Oct 2026) |
|---|---|
| Cement (50 kg bag) | ₹370–415 |
| TMT steel | ₹57–64 per kg |
| Red brick | about ₹6 each |
| Mason (raj mistri) | ₹800–950 per day |
| Helper (majdoor) | ₹450–575 per day (minimum wage ₹436) |
| All-in house construction | ₹1,600–1,700 economy · ₹1,800–2,100 standard · ₹2,200–2,700+ premium per sq.ft |
River sand mining is closed from 15 June to 15 October every year, and sand prices usually rise in that period. Plan your foundation and slabs around it if you can.
Questions people ask
What is the construction cost per sq.ft in Patna in 2026?
Turnkey construction in Patna typically costs ₹1,600–1,700 per sq.ft for economy, ₹1,800–2,100 for standard and ₹2,200–2,700+ for premium specifications. BuildonClick's packages are ₹1,795, ₹2,045 and ₹2,445 per sq.ft including GST.
How much does a 30×40 G+1 house cost in Patna?
On a 20 ft road, a 30×40 ft plot allows about 930 sq.ft per floor after setbacks. G+1 at the Classic package comes to about ₹39.5–45.5 lakh (most likely around ₹41.5 lakh), including the roof stair cabin and parapet, GST and the labour cess. A third floor would exceed the FAR of 2.0 on that road. Enter your exact plot above for your range.
Does the estimate include GST?
Yes. Package rates include 18% GST on the works contract, and the result shows how much of the total is GST.
What is not included?
Plan approval fee (estimated separately above), architect's fee, soil test, electricity and water connections, and interiors beyond the package.
Sources
- Bihar Building Byelaws 2014 and Notification 10713 (Oct 2025): pmaa.bihar.gov.in
- Patna permit fees: Patna BPAS fee calculator
- Seismic zones: IS 1893 (Part 1):2016, Bureau of Indian Standards
- Patna material and labour rates: market surveys, October 2026; Bihar minimum wages from 1 April 2026