I have 2 plots one is north facing slightly bigger than the one south facing. the north facing is located near the side boundary wall away from lawn in a society and south one at the heart of society and a lawn/garden nearby to it.

x2 what Dytecture said, this is not enough to go on. Most important thing before you do anything, is you need to know lot restrictions in that area and what are the zoning requirements, i.e. side, rear,front, set-backs. In addition the size of your house will also depend on the total percentage of a lot that can be covered by impervious surfaces (structures, decks, and surfaces likes asphalt or concrete driveways etc, which reduce natural infiltration, etc and after you obtain that information, only then you can contact a local Architect and you can roughly come up with the size of your house and layout on the lot... until that, the information you get here it will be useless to you in your case and a waste of time for everyone else. With that said, 40x104 is not a confirming lot for most of the area around here and you will need variances because confirming lot sizes usually start at 50x100, unless you in a section where ordinances permit residential cluster development. Good luck.

it's me nidhi

Hello @Cornerstone Design Studio India No. I don't have any idea about FSI. I will try to learn more about it. Regarding the size of green belt, I have confirmed it from the patwari that Plot 1 has got 5 metre green belt on both sides. He told me that: All plots with 24 metre facing road are having 5 metre green belt whereas plots with 12 metre facing road are having 2.5 metre green belt. (It's 4 or 3.5 metre in case of 18 metre road, I don't remember exactly). About that bold line, I am sure that it is not representing width of green belt. (Check below image as that bold line is having same width for 12 metre facing plots). So what do you think now? Should I become that lucky guy to own plot 1? Check out whole map and there are hardly 3-4 corner plots which are having 24 metre wide road on both sides. (and there are just 2 plots having North East direction) whereas there are around 50-55 plots which are similar to Plot 2nd. About your query, It's Suncity Township - I (Sector 35, Rohtak). It's around 45 kilometres away from Delhi border. Would you please mind elaborating this point a little bit more - "For us function prevails over design anyday". If built up area is going to be same in both plots then how it affects functionality? Thanks a lot for your detailed input.