What is FSI (FAR) and how does it affect house construction in India? in Patna
FSI (Floor Space Index), also called FAR (Floor Area Ratio), is the ratio of total built-up area to plot area. FSI of 2.0 on a 1,000 sq ft plot means you can build a maximum of 2,000 sq ft across all floors. Exceeding FSI is illegal and can result in demolition orders.
FSI = Total Built-up Area ÷ Plot Area. Allowed Built-up Area = FSI × Plot Area. Example: 1,500 sqft plot × FSI 1.5 = 2,250 sqft max construction.
City-Wise FSI Limits (Residential Zones)
| City | Residential FSI | Premium FSI (extra paid) | Notes |
|---|---|---|---|
| Mumbai | 1.0–3.0 | Up to 5.0 with TDR | Highest FSI in India for redevelopment |
| Delhi | 1.5–3.5 | — | Varies by plot size in MPD-2041 |
| Bangalore | 1.75–3.25 | — | BBMP zoning-dependent |
| Hyderabad | 1.5–4.0 | — | HMDA Master Plan 2031 |
| Chennai | 1.5–2.5 | — | CMDA regulations |
| Pune | 1.1–2.5 | — | PCMC and PMC jurisdiction |
Building beyond permitted FSI is illegal under all Indian municipal laws. Authorities can seal the building, levy compounding fees (₹500–2,000/sqft of violation), or order demolition. Regularization schemes are not guaranteed.
📍 Patna-Specific Tips for This Topic
Patna's Gangetic alluvial soil is soft — raft foundation strongly recommended for any construction over G+1
High water table in most areas — waterproof basement up to 1.5m above ground level