Renovating an old Kolkata flat? Read this first.

We have renovated apartments built as early as 1962 (in Ballygunge) and as recent as 2014 (in Rajarhat). The 60-year span teaches you one thing: assume nothing about what is behind the wall.

The first-day audit

• RCC and load-bearing walls — never demolish without an architect's signed drawing
• Plumbing risers — usually impossible to relocate; design around them
• Electrical load — older flats are sanctioned for 3–5 kW; modern interiors need 8–12 kW
• Dampness — terrace, common-wall and bathroom dampness are non-negotiable to fix first
• Floor levels — older floors slope by up to 35 mm; budget for screed correction
• Beam projections — measure every beam; they dictate false ceiling design

The five 'hidden' costs of a renovation

• Debris disposal: ₹15k – ₹60k depending on quantum; KMC charges fees per truck.
• Temporary accommodation: families often need 30–60 nights elsewhere during civil rework.
• Waterproofing: ₹250 – ₹650 / sqft. Always re-do bathroom waterproofing.
• Compliance and society approvals: NOC fees, supervisor charges, weekend penalties.
• Provisional civil: shifting an electrical point on site is 5x the cost of doing it in the drawing.

Renovation does not cost more than new construction. It costs differently — and most of the surprises live in the first two weeks.

The renovation-vs-rebuild question

When the cost of renovation crosses 65% of the cost of new construction at the same scale, rebuild becomes the rational choice. We model this for every client at brief stage. Most older Kolkata 3BHKs land at 40–55%, which is firmly in renovation territory.

Three things we always upgrade

• All wiring to copper, multi-strand, with a fresh MCB panel sized for 12 kW
• Plumbing risers extended with PVC + composite, with isolation valves on every fixture
• Waterproofing across every bathroom, kitchen and balcony — non-negotiable

Renovation timeline (realistic)

For a 1200 sqft 3BHK, plan 75–95 working days. Demolition 7 days, civil + waterproofing 18 days, MEP 14 days, wood + ceiling 25 days, finishing 18 days, snag 5 days. Anyone promising 45 days is either lying or skipping waterproofing.