The number on the brochure is not the number you will pay. Most buyers know this in principle. Fewer know how much the gap is, or which items are negotiable and which are not. Here is the full picture for a flat in Kochi, with a worked example at the end.
The government’s share: stamp duty and registration
In Kerala, stamp duty is 8% and the registration fee is 2%, so 10% of the property value goes to the state before you own anything. Two things catch people out.
First, the 10% is charged on the higher of the sale price or the government’s “fair value” for that locality. Fair value is a notified figure per survey number, and in older, well-established areas it can be close to or above the market price. Ask the builder for the fair value of the plot before you sign; it is public information.
Second, it is payable at registration, in full, and it cannot be included in a home loan. This is the single largest cost buyers fail to plan for.
GST: only on under-construction flats
If you buy a flat that is still being built, GST applies at 5% of the agreement value. If the flat qualifies as affordable housing, which means a price of ₹45 lakh or less and a carpet area of 90 square metres or less in Kochi, the rate is 1%. Very few new flats in Kochi qualify.
If you buy a completed flat that already has its completion certificate, there is no GST at all. This is worth understanding when comparing an under-construction flat with a ready one: a 5% difference on a ₹1 crore flat is ₹5 lakh, which changes the comparison.
GST is paid to the builder along with each instalment, so it is spread over the construction period rather than paid in one go.
TDS: a rule that surprises first-time buyers
If the flat costs more than ₹50 lakh, you are required to deduct 1% of each payment as tax at source and deposit it with the income tax department in the builder’s name. The builder gets credit for it; you are simply the collecting agent. Most builders will guide you through this, but the obligation is legally yours, and the penalty for missing it is yours too.
What the builder charges beyond the flat
These vary between builders and are worth asking about line by line.
- Car parking. Sometimes included, sometimes a separate charge. Ask whether it is a covered bay, an open bay, or a stacked mechanical slot, and whether it is allotted or first-come.
- Maintenance deposit or corpus fund. A one-time amount, typically calculated per square foot, held by the owners’ association for major repairs. This is your money in a shared account, not a fee, but it is still cash at handover.
- Advance maintenance. Many builders collect 12 to 24 months of maintenance in advance at handover, to run the building until the owners’ association is formed.
- Electricity and water connection charges. KSEB and Kerala Water Authority deposits are usually passed through at cost. Ask for the figure.
- Legal and documentation charges. Some builders charge for drafting the sale deed and agreement. Ask whether it is included.
- Club and amenity charges. If the project has a clubhouse, gym or pool, there may be a one-time membership charge separate from maintenance.
- Preferred location charge. A premium for higher floors, corner units or a particular view. Usually stated per square foot.
Costs after you have the keys
Interior work is the obvious one. The less obvious one is the monthly maintenance, which in a well-run Kochi building with a lift, generator, security and common-area upkeep will typically run between ₹3 and ₹6 per square foot per month. On a 1,500 square foot flat, that is ₹4,500 to ₹9,000 a month, for as long as you own it. Ask to see the maintenance accounts of a completed project by the same builder; it tells you more about how the building will be run than any brochure.
A worked example
Take a 1,500 square foot, 3 BHK under-construction flat in Kochi at ₹1 crore, with an allotted covered car park.
| Item | Amount |
|---|---|
| Flat, as advertised | ₹1,00,00,000 |
| GST at 5% | ₹5,00,000 |
| Stamp duty at 8% | ₹8,00,000 |
| Registration at 2% | ₹2,00,000 |
| Covered car park (if charged separately) | ₹3,00,000 to ₹5,00,000 |
| Corpus fund and advance maintenance | ₹1,50,000 to ₹2,50,000 |
| KSEB, KWA and documentation | ₹50,000 to ₹1,00,000 |
| Total before interiors | roughly ₹1.20 to ₹1.24 crore |
The gap is 20 to 24% over the advertised price, and around ₹10 lakh of it must be paid in cash at registration, outside the loan.
What to ask for
Ask any builder, including us, for a single sheet listing every payment from booking to keys, with the amount and the date each is due. If a builder cannot produce that, you have learned something useful.
Figures are current as of September 2026 and are indicative. Stamp duty, registration and GST rates are set by government and change from time to time; confirm the current rates before you commit.