Build a two story with a garage under the top story. It will have to be long and narrow lot is not wide. 4 bedrm s will be tight, looks like you only have rm for about 1200 sq ft incl garage. Or you could put front door on side behind garage and stairs inside to go up to bedrooms and bath rooms. Have a small bathroom downstairs. With living area and kitchen, with dining area.

area = 50*35 i.e., 1750 sq.ft

I think it totally depends on two things, 1 The available space 2 Your religious belief. Someone who is very religious may try to squeeze a separate space even in tiny flat, while someone who is not overtly religious may just have a small corner with Idols in spite of being in a position to have a separate room.

Yup, in this case it is possible. But: - - having a proper walk in closet is hard - guest toilet will have to serve as common for living area. - average bedroom size would be around 12'X12'. - If there is staircase it will also take around 60-70 sqft area at least. - Please Note- Around 20-25% of total built up area is just wall area. So like if your house built up area is 1000sqft then the Carpet Area( the area which you will be able to see and use) is around 800sqft. Also, it depends on your lifestyle also, the way you live as it is a very subjective thing. For some people 12'x12' bedroom size is more than enough while some prefer having a 20'X16' bedroom with 10'x8' walk-in closet. It would be better if you could provide layout of the land and other information, there are many other factors that need to be consider for any house design. :)