Start with what the builder handed you
Two identical 3BHKs can differ by several lakh purely on handover specification. Before any design work, we audit what exists and decide what stays, because replacing acceptable flooring is the fastest way to spend a budget on something nobody will notice.
| Handover element | Typical builder standard | Keep or replace? | Cost impact if replaced |
|---|---|---|---|
| Vitrified flooring 600x600 | Mid-grade, acceptable | Usually keep | ₹180 – 420 per sq ft to replace |
| Bathroom tiling and CP fittings | Basic grade, functional | Keep unless renovating fully | ₹85,000 – 2,20,000 per bathroom |
| Internal doors and frames | Flush shutters, hollow core | Keep; upgrade handles | ₹9,000 – 28,000 per door |
| Windows and grilles | Aluminium sliders, plain | Keep; add mosquito mesh | ₹550 – 1,400 per sq ft for uPVC |
| Electrical points and DB | Bare minimum count | Always augment | ₹550 – 1,600 per new point |
| Kitchen platform | Granite slab, no units | Keep the slab, build around it | ₹45,000 – 1,10,000 to redo |
| Paint | Single coat OBD | Always redo | ₹22 – 70 per sq ft |
Excluding 18% GST. The single biggest avoidable spend in flat interiors is replacing serviceable flooring for a marginal aesthetic gain.
The structural rules of an apartment
Most towers built after 2000 use shear-wall construction, where internal walls are structural rather than partition. This is not a society preference — it is the building's lateral stability, and it changes how services are run.
- No chasing into a shear wall. Cutting a channel for conduit compromises the reinforcement cover. Power and data run in the false ceiling void, in skirting-level trunking, or in a thin dry-wall overlay built against the shear wall.
- No openings, no removals. A shear wall cannot be removed to merge two rooms. Where a client wants an open kitchen, the answer is usually a glazed partition in a non-structural wall, not demolition.
- Anchor loads carefully. Heavy wall-hung joinery on a 100 mm block partition needs through-bolting or a backing plate, not plastic plugs.
- The drainage stack is fixed. A WC can move perhaps 300 mm with a floor-level offset before the fall becomes unreliable. Beyond that you are building a step or a false floor, which is rarely worth it.
- Slab loading matters for stone. A full marble floor over vitrified adds real dead load; on a redevelopment-era slab we check before specifying.
The most useful hour on a flat project is the one spent finding out what cannot be changed. Everything after that is design rather than argument.
Greenbox principal designer
Design and build under one accountable roof
Room-by-room scope in a typical flat
| Room | Core scope | Where the money goes | Common omission |
|---|---|---|---|
| Living and dining | TV unit, crockery unit, seating, peripheral ceiling | Feature wall and lighting | Enough power points behind the sofa |
| Master bedroom | Wardrobe with loft, bed with storage, side units | Wardrobe shutter area | A reading light that is not the ceiling light |
| Second bedroom | Wardrobe, study or bed-cum-study | Joinery volume | Planning for a child who grows |
| Kitchen | Base, wall and tall units, countertop, backsplash | Hardware and carcass grade | A dedicated chimney circuit |
| Bathrooms | Mirror unit, vanity, niche, storage | Waterproofing if tiles are lifted | Ventilation when the window is small |
| Entrance and passage | Shoe unit, console, mandir niche | Usually under-designed | Lighting in a windowless passage |
| Balcony and utility | Washing zone, drying, deck or tiling | Weatherproof material choice | A drain point for the machine |
What a flat fit-out costs nationally
| Flat type | Typical carpet area | Essential | Premium | Timeline |
|---|---|---|---|---|
| 1BHK | 380 – 550 sq ft | ₹6.4 – 12 L | ₹9.2 – 18.3 L | 6 – 8 weeks |
| 2BHK | 550 – 900 sq ft | ₹9.2 – 19.4 L | ₹13.3 – 29.7 L | 10 – 12 weeks |
| 3BHK | 900 – 1,400 sq ft | ₹14.5 – 29 L | ₹20.7 – 42.8 L | 12 – 16 weeks |
| 4BHK or duplex | 1,400 – 2,200 sq ft | ₹25.6 – 51.5 L | ₹37.1 – 83.4 L | 16 – 22 weeks |
Excluding 18% GST and civil work. Essential assumes laminate joinery and peripheral ceilings; premium assumes veneer or acrylic, designed lighting and better flooring. Each cell is the per-sq-ft band for that flat size multiplied by the carpet range beside it, and those bands are read off flats we have fitted out and invoiced, costed at October 2026. Run your own numbers on the cost calculator.
Phasing a flat without creating rework
Not everyone can fund a whole flat at once, and in an apartment phasing works cleanly provided the split respects the trade sequence. The rule is simple: anything that involves chasing, ceiling or plumbing happens in phase one, or not at all.
- Phase one, always together: electrical augmentation, plumbing changes, waterproofing, false ceiling, and the kitchen. These are the disruptive trades and doing them twice means living through it twice.
- Phase two, comfortably later: bedroom wardrobes, study units, and the second bathroom vanity. Joinery is a clean trade that can be installed into a finished flat in days.
- Phase three, any time: loose furniture, soft furnishings, art, and the balcony. No dust, no downtime.
- Never split flooring, ceiling or painting across phases within the same visual zone. The join will always show.
The snag list at builder handover
Before your own work starts there is a separate exercise worth doing properly: snagging the builder. Most developers offer a defect liability period of twelve months, and the items you record at handover are the ones they will fix free.
- Test every socket, switch and light point against the drawing. Missing and dead points are the most common builder defect and the cheapest one to have someone else fix.
- Fill each bathroom floor and leave it for two hours. A ponding test at handover catches waterproofing failures before your tiles go down on top of them.
- Check every door and window for square, smooth operation, and seal integrity. Aluminium sliders that bind at handover will not improve.
- Tap the flooring. A hollow sound means a tile has not bedded and will lift within two years.
- Photograph everything and submit in writing within the defect liability window. A verbal complaint to a site engineer is not a record.
- Do this before your contractor starts, because once you begin work the builder will reasonably attribute every defect to your team.
Where we work
We take apartment projects across India. For Mumbai carpet areas, society approvals, redevelopment-flat quirks and suburb-level pricing, see flat interior designers in Mumbai.
Selected work by Greenbox Design Studio. Tap any image to enlarge.
Frequently asked questions
What is included in flat interior design?+
Space planning within the fixed shell, joinery for every room, modular kitchen, false ceiling and lighting, electrical augmentation, wall and floor finishes, bathroom storage, and — with a design-and-build studio — the execution and handover. Structural changes are not included because in most towers they are not permitted.
Can I remove a wall between two rooms in my flat?+
Usually not. Towers built after 2000 generally use shear-wall construction where internal walls carry lateral load, and society bye-laws prohibit altering them regardless. Where a wall is a non-structural block partition, removal may be possible with written society permission and a structural consultant's confirmation.
Should I replace the builder's flooring?+
Usually not. Mid-grade 600x600 vitrified flooring is serviceable, and replacing it costs ₹180–₹420 per sq ft plus a fortnight of disruption and debris. Spend the same money on lighting, joinery and the kitchen, where the daily difference is far more noticeable.
How long does a flat interior project take?+
Six to eight weeks for a 1BHK, 10–12 for a 2BHK, 12–16 for a 3BHK and 16–22 weeks for a 4BHK or duplex, measured from design sign-off and assuming no major civil work. Buildings that restrict working hours add roughly 20% to each of these.
Can I do my flat interiors in phases?+
Yes, provided the split follows the trades. Electrical, plumbing, waterproofing, ceiling and kitchen all belong in phase one because they are disruptive and interdependent. Bedroom wardrobes, study units and loose furniture can follow months later with no rework, as joinery installs cleanly into a finished flat.