The workbook in full
All six stages below. Stage one is the one people skip, and it is the one that decides the budget.
Stage 1 · Understand what you have
- Age of the building and the year of the last major plumbing replacement
- Existing wiring type and whether the DB has an RCCB
- Known seepage history, including complaints from the flat below
- Which walls are structural — confirmed, not assumed
- Whether the slab is sunk or non-sunk in each wet area
- Any previous unauthorised alteration that the society has on record
Stage 2 · Decide the scope honestly
- List what must change, what should change and what you merely dislike
- Decide whether plumbing is being replaced or reused — this sets the budget
- Decide whether you will live in the flat during the work
- Decide the phasing if you are staying: one room at a time or wet areas first
- Set a contingency of 12 to 15 per cent; renovations find things
Stage 3 · Permissions and neighbours
- Society NOC with the scope described accurately, not minimised
- Written confirmation of working hours and the noisy-work window
- Neighbours above, below and adjacent informed in person before work starts
- Debris route, chute timings and the society's nominated contractor confirmed
- Structural undertaking submitted where any wall is being touched
Stage 4 · Sequence the work
- Demolition and debris out before anything new arrives
- Plumbing first fix and pressure test before any wall closes
- Waterproofing with a photographed ponding test before tiling
- Electrical chasing and conduit before plaster, with the point schedule signed
- Ceiling and tiling before joinery arrives on site
- Painting after joinery carcasses, touch-up after installation
Stage 5 · Living through it, if you are
- One sealed room set up as a dust refuge with its own AC
- A temporary kitchen: induction plate, kettle, microwave, a sink you can reach
- One functioning bathroom at all times, agreed in the programme
- Daily clean of the corridor and lift lobby written into the contract
- Weekly walk with the supervisor at a fixed time
Stage 6 · Close it properly
- Snag walk room by room with the list written, not spoken
- Ponding test evidence, warranties and as-built drawings collected
- Society deposit refund applied for with the debris clearance certificate
- Retention held for 30 days of actual use
- Second snag walk after a month, then release
How to work through it
- Do stage one before you set a budget. The age of the concealed plumbing is worth more to know than any design preference.
- Decide the plumbing question explicitly. Replace or reuse is the single largest budget fork in an older Mumbai flat.
- Phase the work if you are staying. Wet areas first, one room at a time, with one bathroom always functioning.
- Tell the neighbours in person before work starts. It costs an evening and prevents most complaints.
Three renovation-specific risks
- Concealed plumbing in a building over 25 years old. Budget to replace it; discovering it mid-project costs far more.
- A wall that turns out to be structural. Stage one confirms rather than assumes, and the confirmation is cheap.
- An unauthorised alteration on the society record from a previous owner, which becomes your problem at NOC stage.
Read renovating an old Mumbai flat and check rates on the home renovation cost page.
Frequently asked questions
Should I stay in the flat during renovation?+
If the scope is one room or one bathroom, yes, with a sealed dust refuge and a temporary kitchen. For a full-flat renovation, moving out shortens the programme by roughly three weeks and improves the finish, because trades can overlap instead of queueing around your life.
Does concealed plumbing always need replacing?+
In buildings over about 25 years old, usually. Galvanised iron lines from that era scale internally and leak at the joints. The wall is already open during a renovation, so the marginal cost of replacement is a fraction of doing it as an emergency later, and every surveyor will tell you the same thing.
What contingency should a renovation carry?+
Twelve to fifteen per cent, and up to twenty in a building over forty years old where both plumbing and wiring may be at end of life. A new-flat contingency of seven per cent does not survive contact with a Mumbai renovation.
How long does a full flat renovation take?+
Sixteen to twenty weeks for a 2BHK if you have moved out, and add three weeks if you are living in it. Demolition, debris and plumbing first fix alone account for four to five weeks before anything visibly improves.
What if the society objects mid-project?+
Usually because the work on site looks larger than the scope in the NOC letter. Describing the scope accurately at application stage prevents almost all of it. If an objection arrives, stop, meet the committee with the drawing, and get the variation approved in writing before restarting.