Investing in an off-plan property in Dubai

I am an Indian citizen. I wish to invest in an off-plan property in Dubai. Specifically, I am interested in knowing the following:

1. Is there any standardized law (legally binding on the property developers) regarding the calculation of the property units' saleable area?

2. If yes, what is the Law No.?

3. Whether the saleable area is calculated based on - Net Internal Area (Carpet Area) OR - Including Wall Areas OR - Including common Areas?

3 A. If Wall/common areas are included, how much (%) of the wall area is added over & above the Net unit area?

4. Whether parking space is included in the saleable area of the unit or paid separately?

5. Whether the balcony area is calculated at the full rate the same as the unit area?

6. Whether it is required by law that the developer should mention the method of calculation of saleable area in the SPA?

If all this information is available in any law/resolution, that would also suffice.