What All Should One Take Care Of Post Redevelopment ?
Some of the primary documents received by the builder, by the Corporation, after the house redevelopment or house remodelling work is complete are the Possession Letter, the Occupancy Certificate and Completion Certificate.
All these documents are issued only after each and every aspect of the house remodelling work is inspected stringently by the concerned authorities. One of the most important aspects of the inspection includes verification of the newly built-up area (mentioned on papers and drawing).

Considering the fact that a builder gives 10-15 years of guarantee to the house owner, with free rectifications for any structural damage or defect unless caused by the homeowner himself/herself (for which he/she has to pay for the rectifications).
Once the homeowners move back into their respective apartments after the renovations,
It should be their priority to cross-check the area of each room of their apartment. It can be done in two ways; either by comparing the areas of the existing floor plan and the new one and measuring the difference between the two or by measuring the area while the renovation work is/was going on.

The most advisable tip would be to check for the area while the house remodelling work is going on as it makes it easier to put forth changes, if any. Moreover, once the renovations are done with, the only thing a house owner can do is accept the apartment/house as it is being given.
However, this applies only to home renovation/redevelopment projects only and not new constructions.