Under construction property - builder has hidden carpet area information

As per RERA Act flats have to be specified in terms of what is known as RERA carpet area.  RERA carpet area is built-up area minus the area under the outer walls of the flat. The thickness of the outer wall in modern RCC buildings will be about 229mms. If the built-up area is known and if the dimensioned plan of the flat is available, it would be possible to calculate the RERA carpet area. You can go to consumer court against the builder. It is advisable that you take the help of a lawyer and an archetect. Do not make any further payment until the issue is settled. There may be other purchasers. Try to collect them and make joint application.

Typically, the carpet area is 60-70% of the super built-up area in residential housing projects with several amenities and open space." This is calculated as the carpet area plus the area covered by walls, balconies, terrace and exclusive corridors, if any, all meant for the home owner's exclusive use.

If you suspect the builder to play fraud and if you have evidence to prove that you can issue a legal notice and then make a complaint against the builder with RERA for necessary relief 

I am trying to find other buyers and ask them.

If the time comes, should I go to RERA or Consumer forum? Since the project has received RERA id (seen online , not informed by builder) much later than my Sale agreement registration date.

In sale agreement, only super built up has been mentioned whereas in RERA, RERA carpet area & built up area has been mentioned - the difference of the two (RERA carpet area vs super built up area which is used for payment consideration ) is coming to more than 40% - that is my issue. I was only verbally told at every step that this is 30% (initially 25%) and shown once in one booklet but that was not provided to us nor available online.

Also the carpet area info is intentionally not mentioned anywhere other than RERA.

My unit is currently under construction.

Yours is an under construction property.

If the sale agreement is not clear about the extent of the carpet area and the built area, then you can write a letter to the builder and send it by registered post (avoid email correspondence) clarifying the details and demand a repl;y witghin 7 days, if there is no response then you may issue a legal notice to the builder clarification and instruct  the builder to specify the extent of the carpet area or cancel the booking and return the amount with interest from the date of booking.

If the builder's response is not sastisfactory then approach RERA immediately seeking relief and remedy

Please always mention the location where you have purchased the property to get appropriate guidance keeping in view local laws.

If it's in Multiple you can get access to all documents and correspondence between BMC and the developer if you have the File No. as BMC uploads them on it's website.

It's in Kolkata, West Bengal

Yes, you may issue legal notice and take up the issue with RERA, as already suggested.

Thanks for all your comments.

If I may add something that I have missed earlier. When I had booked the pre-construction property, the developers had not yet applied for RERA certificate. So our payment sheet was based on the super built up area. To it addition of parking + GST + extra charges.

Now that I know they have RERA certificate (which they haven't informed us), shouldn't the payment be based on RERA Carpet area. Would I have a case , as builder has intentionally hidden the information that it has applied for RERA and still charging me (as per demands) on super built up area (where there is a loading factor of more than 40%)?

You can proceed by taking initiations as advised earlier.

Issue a legal notice demanding the clarification about the actual extent of the carpet area , built up area and super built up area from the builder, failing to respond you may approach RERA with a complaint against the  builder's fraudulent activity. 

If the drawings are available now one can find out exact carpet area of the flat corresponding to the super-built up area. Whether the builder should give you carpet area equal to the super built-up area, or give you a reduction in price, only a court can decide.