Under-Construction vs Ready-to-Move Flats in India (2026): What the Wait Actually Costs
The advice on this decision is remarkably consistent, and remarkably useless. Under-construction is cheaper but risky. Ready-to-move is safer but dearer. Choose according to your situation. Every builder blog, bank blog, and portal guide lands in the same place, and none of them does the one thing that would help: put both flats on a single line, with the cost of the wait included, and see which number is larger.
That is what this page does. The result is not the interesting part. The interesting part is how small the wait turns out to be, and what that says about the discount you are being offered.
GST, and why the two prices you are quoted are not comparable
Before any arithmetic, one correction, because it is stated wrongly almost everywhere.
A flat still under construction attracts 5% GST, or 1% if it qualifies as affordable housing (agreement value up to ₹45 lakh, with carpet area within 60 sq m in the metros and 90 sq m elsewhere). A completed flat sold after its completion certificate attracts nil. So far, so widely known.
What gets garbled is the base. GST law grants a mandatory one-third deduction of the total consideration towards the value of land, and the statutory rate sits at 7.5%, levied on the remaining two-thirds. Those two facts are designed to cancel: 7.5% on two-thirds is 5% of the whole. The 5% you are quoted is already the effective rate on the full agreement value. Several widely-read guides apply the one-third deduction a second time and arrive at about 3.35%, which understates the tax by roughly ₹1.34 lakh on an ₹80 lakh flat. On our ₹85 lakh flat below, GST is ₹4,25,000, not ₹2,83,000.
The second incomparability is the one this page is about. A ready flat is a home you occupy tonight. An under-construction flat is a promise of a home in three years, during which you live somewhere else and pay for the privilege. Those are different goods at different dates, and comparing their sticker prices compares nothing.
The worked example
Two buyers, the same locality, the same size of flat, the same bank.
- The ready flat: ₹1,00,00,000, possession immediate.
- The under-construction flat: 15% less at ₹85,00,000, possession promised in 36 months. That is the midpoint of the 10% to 20% discount the market quotes.
- The loan: 80% of the agreement value in both cases, at 8.5% for 20 years. The 20% down payment is the floor the RBI's LTV caps effectively set for a loan of this size.
- Stamp duty and registration: 7% of the agreement value, in the middle of the 5% to 8% range across states. It scales with price, so the cheaper flat pays less.
- Rent while waiting: ₹30,000 a month, escalating 8% a year, the middle of what Indian agreements build in, plus one month's brokerage. On a ₹1 crore flat that rent is a 3.6% gross yield, which is about right for an Indian metro.
- Society maintenance: ₹4,000 a month, paid by the buyer who has moved in and by nobody on a building site.
- Pre-EMI: interest only, on the money the bank has actually released. A construction-linked plan is modelled here as equal monthly tranches across the 36 months.
Both buyers own the same finished flat on the same day, month 36. Because the asset is identical at that point, any appreciation accrues to both and cancels out of the comparison. What does not cancel is what each of them has committed to get there: cash already paid, plus the debt still outstanding.
The bill at handover: ₹1.28 crore against ₹1.16 crore
| By month 36 | Ready-to-move | Under-construction |
|---|---|---|
| Price | ₹1,00,00,000 | ₹85,00,000 |
| GST | Nil | ₹4,25,000 |
| Stamp duty and registration | ₹7,00,000 | ₹5,95,000 |
| Interest paid, 36 months | ₹19,78,212 | ₹8,91,083 |
| Rent and brokerage | Nil | ₹11,98,704 |
| Society maintenance | ₹1,44,000 | Nil |
| Total committed | ₹1,28,22,212 | ₹1,16,09,787 |
The under-construction buyer is ₹12,12,424 ahead, holding an identical flat. The ready-to-move buyer's ₹19.78 lakh of interest is the item that surprises people: three years of full EMI on a ₹80 lakh loan at 8.5% costs more than twice the ₹8.91 lakh of pre-EMI on a tranched ₹68 lakh loan, and the difference alone is close to the entire rent bill.
Three years of rent and pre-EMI cost about 5% of the price
Run the discount down until the two totals meet, and the crossing point is 5.10%. An under-construction flat priced at ₹94,89,869 against a ready ₹1 crore flat leaves the buyer exactly indifferent after three years of rent, pre-EMI, and GST.
The result moves with the rent, which is the largest single cost of waiting, so it is worth seeing how far.
| Rent on the same ₹1 crore flat | Gross yield | Discount needed to break even |
|---|---|---|
| ₹20,000 | 2.4% | 1.84% |
| ₹25,000 | 3.0% | 3.47% |
| ₹30,000 | 3.6% | 5.10% |
| ₹35,000 | 4.2% | 6.73% |
| ₹40,000 | 4.8% | 8.36% |
Even at ₹40,000 a month, a yield well above what Indian metros actually produce, the wait costs 8.36%. The market is offering 10% to 20%. On cost alone, and on time, under-construction wins across the whole plausible range, and it is not close.
Which raises the real question. If the wait costs five per cent and the discount is fifteen, what is the other ten per cent paying for?
What the rest of the discount buys: room for the project to slip
It is paying you to carry the risk that the flat arrives late, or does not arrive. That risk is not hypothetical. Anarock's count of housing launched on or before 2014 and still stuck or delayed runs to roughly six lakh units worth over ₹5 lakh crore across seven cities, with 1.13 lakh of them in NCR alone. Its 2026 assessment puts 5.4 lakh homes across the top seven cities under delivery pressure, the worst position since 2020.
So the discount is best read as a budget for lateness. Hold every other assumption still and extend the wait, and the arithmetic gives you the exact size of that budget.
| Discount taken | Total wait it survives | Delay beyond the promised 3 years |
|---|---|---|
| 10% | 4.4 years | 1.4 years |
| 15% | 5.9 years | 2.9 years |
| 20% | 7.3 years | 4.3 years |
A 10% discount buys you about seventeen months of slippage before you would have been better off buying the finished flat. That is less cushion than the market's own delay record suggests you need. A 20% discount buys more than four years, which is a genuinely different proposition.
The cost of each additional year also rises rather than holding steady. On the 15% flat, the first year of delay burns ₹3,85,667 of the advantage, the second ₹4,10,091, and the third ₹4,69,022. Rent escalates every year while not one rupee of principal is being repaid, so a project that slips keeps getting more expensive to wait for.
When a ready-to-move flat is the better buy
The arithmetic above assumes the promise is kept. Several situations make the ready flat the stronger choice regardless of the gap:
- You cannot carry both payments. By month 36 the under-construction buyer is paying ₹48,167 of pre-EMI and ₹34,992 of rent, ₹83,159 a month, against ₹69,426 for the ready flat's full EMI. Waiting is cheaper in total and dearer every month, which is the reverse of how it is usually sold. Developers answer this with "no EMI till possession", though a subvention scheme mostly moves the interest into the price.
- The discount is under about 10%. Below that, the delay budget is thinner than the market's delivery record justifies.
- You are buying what you can inspect. A finished flat has a floor you have stood on, light you have seen at 4pm, and neighbours you can ask. A brochure has none of these.
- The tax deduction starts now. Interest paid before possession cannot be claimed as it is paid. Under Section 24(b) it is accumulated and deducted in five equal instalments from the year construction completes, inside the same ₹2 lakh ceiling for a self-occupied property, so a good part of it is capped away in practice. If the build overruns five years the ceiling itself falls to ₹30,000. These figures are pre-tax throughout and do not include that asymmetry, which runs against the under-construction flat.
When an under-construction flat is worth the wait
- The discount is 15% or better and the developer's record is real. Delivered projects in the same city, not promised ones, are the only evidence worth weighing.
- You are already renting and would go on renting anyway. The rent in the table is then not a new cost of waiting; it is a cost you were paying regardless, and the comparison shifts further in favour of waiting.
- Your money is doing something in the meantime. The under-construction buyer commits less cash for three years. Left invested rather than spent, that gap is worth more than the table credits, since these totals ignore the time value of money entirely.
- The project is RERA-registered with a firm dated possession clause. It does not remove the delay, but it puts a compensation obligation behind it.
The risk no discount prices: a project that never finishes
Total delivery failure is not a delay, and no discount prices it. The tables above assume you eventually get the flat; buyers in genuinely stalled projects are not comparing totals, they are litigating. Nor is the loan risk symmetric: a bank that has disbursed against a stalled building still wants its interest, and a stalled buyer keeps paying rent at the same time.
That double payment is the part of this decision that hurts most and is discussed least. Three years of rent and pre-EMI together come to ₹20,89,787 on this flat, and none of it repays a rupee of principal.
Working it out for your own flat
The numbers here are one flat at one price with one rent, and every line of them moves with yours. Two of the site's calculators do most of the work: the EMI Calculator gives you the interest either loan actually costs over any window, and the True Rental Expense Calculator prices the rent you would pay while waiting, escalation, brokerage, and deposits included. If the flat is an investment rather than a home, the Rent vs Buy Calculator is the one that puts the whole holding period together.
The rule of thumb this page leaves you with is short. Work out the wait as a percentage of the ready price, which will usually land near 5%. Subtract it from the discount on offer. What remains is your compensation for delay risk, and the only question left is whether that is enough for the developer in front of you. Nobody can answer that with arithmetic. But you should at least know what you are being paid.
If this settles you on a finished flat, the next question is whether to buy it from the builder or from whoever lives there now, and a resale has to be about 12.5% cheaper before it actually saves you anything. Buying costs more than the price and the EMI on either side of this choice; the full list of what ownership adds runs well beyond twenty items. And if you are renting while you decide, the ten-year bill for that is larger than the rent suggests too.