Sinking fund

State

State is Maharastra and District is Pune.

OK , My state 

1) Problem is bit complex in such case , if you go minutely . First you need to examine Occupying certificate and builiding Plan which is attached with OC

2) There are heavy chances the open area is marked as common area of society or it is not properly marked. Or not even existing :P This require examination

3) Under Maharashtra Regional Town Planning Act ,which maks Development Control Rule of Pune under it After every room some open space have to be kept, after every flat car parking /two wheer parking is reuired to be kept in plan. Specific Open Spece to required to be kept. This is done so human habitat is good and proper.

4) Builders sell this area too , although not supposed to sell common area. In registration office if you go hardly registrar have time to check office he just scan and put stamp and forget and not bothered . So this builders change flat plan and some time show marking on area  which they are not supposed to sell legally

5) So when such dispute takes place , in my opinion only balcony next to flat which is kept compulsory for room as per Development Control rule should be charged and further area should be considered as common area of the society

6) This all question will arise again after 50-60 years when Redevelopment of society will take place because bulding life is only 30-40 years and now with present development control rules if you have to think of alloting flat  in redevelopment only area which is marked in original occupation plan should be considered (There are some benefits for redevelopment specal rules in some city) . So they are not considering extended area for some benefits

7) So I feel you need to include balcony which is attached to room as per D.C. Rules and Plan and ignore extended area as it is common area of society.

8) In Society meeting try to take on record Occupying certificate and building plan and determine which is common area in Plan and which is not common area. . Exclude Common area from individual calcuation 

9) Now this statement will be from my point of view because I have taken MRTP and Co-oprerative society act views together. but some one other can defer let them put their view on it. My concentration was from MRTP and building plan point of view