1)you can construct another floor only if building plans are sanctioned by BBMP

2) contact a local architect . he will assit you in preparation of plans for construction of addityional floor and obtaining approveal from authoritiies

3) further consent of your father , brother is a must before additional construction would be permitted

4) if you construct temporary structure it would be demolished as it is unauthorised construction

5)assessment for property taxes vary depending upon whether usage is residential or commercial

6) your water bill will also increase if usage is commercial

7) for installation of lift in the property permission is required of BBMP . further inspector of lift must certify that lift is fit for usage

1. The building rules differs in every city, every state.

2. So you will have to check with the Municipality of your state .

3. In general circumstances width of road in front of your house permits constructions of 4 storied building.

4.So first apply for building plan.if it is not allowed then we can think further.

1. You shall have to submit a construction plan to BDA for constructing the additional floor and await its approval.

2. there is no rule for erecting temporary structure unless the loacal people file objection for your said erection of temporary structure on some ground or other.

3. The authority may give you notice for dismantling the said temporary structure with in a specific time limit and in case if failure, they may demolish the same and charge a penalty on you.

4.For conversion from residential to commercial building, the tax of the building will certainly change upward.

You say that all the three floors have been registered separately among the three users on their respective names, hence the terrace is common for all the three.

Thus no structure can be raised in the common area until there is a common agreement for common usage.

Once the building has been registered as a residential place the terrace proposed to be used for commercial purpose may not be permitted.

Generally in a building which is semi commercial and semi residential, the ground and the first floor may be permitted for commercial activities and not beyond that.

However you can contact a local consultant who would be having a different idea to utilise the common terrace for the benefit of all the occupants by obtaining permission or plan approval accordingly to raise at least a temporary structure as desired by you.