Renovation vs New Interiors: Cost Comparison

Two families buy 3BHK flats of the same size in the same city in the same month. One takes possession of a new flat from the builder; the other buys a twenty-year-old resale flat in an established neighbourhood. Both ask a designer for a mid-range interior, and both are quoted a similar per-square-foot rate. Six months later the second family has spent far more — and usually feels it was cheated. It was not. The interior cost the same; the difference was everything underneath it.

A new flat comes with fresh wiring, new plumbing, waterproofed bathrooms, new flooring and windows; the interior goes on top. An older home often needs those things replaced before any furniture can be built — and each of them involves breaking, removing, disposing and rebuilding, in an occupied building, under society rules. That renovation layer is the real cost difference, and it is often missing from first quotes because it is hard to see until the walls and floors are opened.

This guide separates the two clearly. It uses the same indicative October 2026 rates as the rest of this site — per-square-foot interior bands, bathroom, wiring, plumbing, flooring and painting rates — and shows how they combine into a like-for-like comparison of a new 3BHK and a renovated one. It also covers time, risk, when a partial refresh is the smarter choice, and how to compare a resale flat plus renovation against a new flat.

Four kinds of interior project

The word renovation covers very different scopes, and most cost confusion starts with mixing them up. It helps to name four levels. New interiors means fitting out a builder-finished flat or house: walls plastered and painted, floors laid, bathrooms tiled and fitted, wiring and plumbing done, and the designer adds joinery, ceilings, lighting and finishes. A refresh keeps everything fixed — floors, bathrooms, wiring, kitchen carcass — and changes only paint, soft furnishings, lights and perhaps shutters. A partial renovation replaces one or two systems, typically the kitchen and one or two bathrooms, and adds new furniture. A full renovation strips the home back to its walls and slab and rebuilds the services and finishes before the interior goes in.

The refresh band is deliberately wide and modest: painting a 1,000 sq ft flat at all-in emulsion rates of ₹12–30 per sq ft of paintable area, new curtains, a few light fittings and some loose furniture rarely needs more. The partial and full renovation figures are built up in the sections below.

How Indian homes have been renovated

For most of the twentieth century, Indian homes were renovated incrementally. A family would add a room, re-floor the ground floor in mosaic or Kota stone, re-plaster after the monsoon, or replace a kitchen platform, one job at a time, usually with a local mistri and materials bought by the owner. Many older flats in Indian cities still carry the evidence: mosaic or marble floors laid in the 1980s and 1990s, galvanised iron water pipes, wiring sized for a few fans and tube lights, and bathrooms waterproofed with brickbat coba.

From the 2000s, two changes reshaped the business. Factory-made modular kitchens and wardrobes turned interiors into a design-and-install product with a per-square-foot price, and the resale market in older city neighbourhoods grew as families wanted central locations. The per-square-foot price was designed for new flats, where the services are new. Applied to an older flat, it tells only half the story — which is why renovation budgets so often overrun.

The base rate is the same — the renovation layer is not

For the same specification, the interior itself costs about the same in a new flat and an old one. A wardrobe in BWR plywood with laminate shutters costs the same per square foot of elevation in either; a gypsum ceiling costs ₹60–80 per sq ft plain and ₹80–180 designer in either. This site's city and room guides use tier-2 bands of about ₹800–1,200 per sq ft of carpet area for basic interiors, ₹1,200–2,000 mid-range and ₹2,000–3,500 or more premium, with most complete homes landing at ₹1,400–1,800.

What an older home adds is a set of tasks that a new home does not need. They fall into seven groups: strip-out and disposal; civil changes such as moving a non-structural wall or a door; electrical rewiring; plumbing and bathroom rebuilding; flooring replacement; repairs to plaster, waterproofing and windows; and the overheads of working in an occupied building — protection, society deposits and, if the family stays, temporary arrangements. The table gives indicative October 2026 ranges for each, using the same figures as this site's specialist guides.

These line items come straight from this site's guides on hidden costs, bathroom renovation, electrical wiring, plumbing, tile laying and living at home during works, so they can be cross-checked. The removal rate for old floors is a new indicative range and depends heavily on what lies underneath; a thick mortar bed, an old mosaic floor or a waterproofing layer in a sunken area all change the effort.

A like-for-like comparison: one 3BHK, new and renovated

Take a 1,250 sq ft carpet-area 3BHK with three bathrooms, done to a mid-range specification. As a new-possession flat, this site's 3BHK guide puts the interior at about ₹15.5–22.5 lakh before loose furniture and appliances. As a twenty-year-old resale flat needing a full renovation, the same interior sits on top of a renovation layer. Fig. 1 shows the build-up at mid-points of each range.

Three things stand out. First, bathrooms dominate the renovation layer: three full bathroom rebuilds can cost more than all the other renovation items together, which is why deciding bathroom by bathroom is the single biggest lever. Second, rewiring is rarely optional in a home older than about twenty years, for safety reasons explained below. Third, flooring is a choice: where levels and condition allow, overlaying new tile or a floating floor on the old one avoids most of the removal cost.

Per square foot, the full renovation lands at roughly ₹1,800–3,000 of carpet area, against ₹1,200–2,000 for the same mid-range interior in a new flat. That is the honest comparison to give a family before they buy a resale flat, not after.

Time: why renovations take longer

This site's timeline guide puts a mid-range 2BHK or 3BHK with factory-made furniture at about 10–16 weeks on site after design sign-off, with resale flats needing heavy civil work at 18–24 weeks or more. The extra time is not inefficiency. Strip-out has to finish before services can be laid; wiring and plumbing must be tested before plaster; bathrooms need waterproofing, a flood test and curing before tiles; floors must be laid before furniture is measured; and every noisy job in an occupied building is limited to permitted hours. Fig. 2 shows how the two programmes compare.

What to keep, what to replace

Not every old home needs a full renovation, and the best renovation budgets are built system by system. The question for each system is the same: is it safe, does it work, and will it last as long as the new interior? If the answer is yes, keeping it is the cheapest decision in the project. If it is no, replacing it after the interior is built will cost several times more, because it means breaking new work.

Wiring: the safety question

Wiring is the system most often kept when it should not be. Homes built two or more decades ago were often wired for far smaller loads than a modern family uses — several air-conditioners, a geyser in every bathroom, an induction hob, a microwave, a washing machine. Signs that rewiring is needed include warm or discoloured switches, frequent tripping, no RCCB, no proper earthing, undersized conductors and old wiring with brittle insulation. A licensed electrician should test the installation; where in doubt, rewire. Rewiring a 3BHK at about ₹1.5–3.5 lakh with a new distribution board and 30 mA RCCB protection is far cheaper than any of the alternatives.

Plumbing and bathrooms: the leak question

Older Indian buildings commonly used galvanised iron water pipes, which corrode from the inside, reduce flow and eventually leak inside walls. Bathrooms waterproofed decades ago may still be dry — or may already be leaking into the flat below. Before deciding, check water pressure at every tap, look for damp patches and efflorescence on walls next to and below the bathrooms, and ask the neighbour below. If the bathroom is to be kept, at least replace the concealed supply pipes where accessible; if it leaks, rebuild it fully with new waterproofing and a flood test, because tiling over an untested membrane only hides the problem.

Floors: the level question

Old mosaic, Kota or marble floors in good condition can often be ground and polished rather than replaced, and some are worth keeping for their character. Where new flooring is wanted, there are two routes: strip the old floor and bedding and relay, or overlay new tiles or a floating floor on the existing surface. Overlay is faster, quieter and cheaper, but it raises the floor and needs a sound, level base. Fig. 3 compares the two.

Resale flat plus renovation, or a new flat?

For a buyer, the real comparison is not renovation against new interiors; it is the total cost of a resale flat plus its renovation against a new flat plus its interiors, with time and risk considered. The arithmetic is simple and worth doing on paper before any booking amount is paid. Add the purchase price, stamp duty and registration, the renovation layer and the interior for the resale flat; add the purchase price, stamp duty and registration, any builder charges and the interior for the new flat. Then compare on carpet area, because that is what the family will live in.

An illustrative example shows the method. Suppose a resale 1,250 sq ft carpet flat is cheaper to buy than a new one of the same carpet area by ₹15 lakh. A full mid-range renovation adds roughly ₹7–15 lakh more than new interiors would, and about two months more on site. The resale flat is then still ₹0–8 lakh cheaper overall, in a better location — but with more uncertainty, because the condition of the hidden services is not fully known until work starts. If the purchase-price gap were only ₹5 lakh, the new flat would usually win. These are illustrative numbers to show the method; actual prices vary widely by city and locality.

Two further points belong in the comparison. A new flat registered under the Real Estate (Regulation and Development) Act, 2016 carries the builder's obligation to rectify structural and workmanship defects reported within five years of possession, so defects in a new flat should be reported to the builder rather than fixed at the owner's cost. A resale flat carries no such cover for the new owner from the original builder in practice, so the renovation contingency must be larger. And an older building may need society-level repairs — terrace waterproofing, structural repairs, lift replacement — that are paid through the society and are separate from the flat's renovation; it is worth asking the society for recent and planned repair levies before buying. This is general information, not legal advice.

GST, fees and the contingency

Both kinds of project carry the same overheads on top of the figures above: GST on the works and materials invoiced, commonly 18 per cent on interior contracts; design fees, whether a percentage, a per-square-foot rate or a lump sum; and loose furniture and appliances, which this site budgets separately. A renovation should carry one more line: a contingency for what is found when walls and floors are opened. Aaditya Interior recommends a contingency of about 10–15 per cent of the renovation layer for homes in fair condition and more for very old homes or where a bathroom is known to leak. In a new flat, a contingency of about 5 per cent is usually enough.

Where renovation is heading

Renovation is becoming a larger share of interior work in Indian cities as older housing stock ages and central locations become harder to buy new. Three trends make it easier. Overlay products — thin large-format tiles, SPC and other floating floors, and panel systems for walls — reduce demolition and dust. Surface-mounted and wireless electrical options reduce the need to chase every wall when only a few points change. And better pre-purchase surveys, using moisture meters, thermal cameras and socket testers, turn hidden conditions into known ones before the budget is fixed. The principle stays the same: survey first, decide system by system, and price the renovation layer separately from the interior.

Rules for budgeting a renovation

• Survey before designing: test wiring, check pipe material and pressure, look for damp, and tap floors and walls for hollows.
• Price the interior and the renovation layer separately, so each can be compared with new-flat quotes and with each other.
• Decide bathrooms one by one — they are the largest part of the renovation layer.
• Treat rewiring as essential in homes with old, undersized or unearthed wiring; it is a safety item, not a luxury.
• Overlay floors only on sound, level, well-bonded bases, and plan door trims and thresholds for the raised level.
• Keep a contingency of about 10–15 per cent of the renovation layer, more for very old homes.
• Get the society's renovation rules, deposits, working hours and any planned building repairs in writing before work starts.
• For a resale purchase, compare total cost — price, duties, renovation layer and interior — on carpet area against a new flat.

Frequently asked questions

Is it cheaper to renovate an old flat or do interiors in a new flat?

For the same size and specification, interiors in a new flat are cheaper, because the services and finishes are already new. A full renovation of an older flat typically costs about 45–70 per cent more than new interiors for the same mid-range specification, mainly because of bathrooms, rewiring and floors.

What does a full house renovation cost per sq ft in India?

At indicative October 2026 rates, a full mid-range renovation of a flat lands at roughly ₹1,800–3,000 per sq ft of carpet area, including the interior. Basic renovations cost less and premium ones much more, depending mostly on bathrooms, flooring material and finishes.

Should I rewire an old flat during renovation?

If the wiring is older than about two decades, lacks earthing or RCCB protection, shows heat marks or trips often, yes. Have a licensed electrician test it. Rewiring during renovation costs far less than opening new walls and ceilings later.

Can new tiles be laid over old tiles?

Yes, if the old floor is sound, level and well bonded, with no hollow tiles. New tiles on 3–6 mm of tile adhesive raise the floor by about 13–16 mm, so doors, thresholds and skirting must be adjusted. Wet areas should not be overlaid without checking the waterproofing.

How long does a full flat renovation take?

Typically 18–24 weeks or more on site after design for a 2BHK or 3BHK, compared with about 10–16 weeks for interiors in a new flat. Living in the home during the works stretches the programme further.