Ground floor construction in 30*40 site

[btbda]

Hi
I am planning to construct 30*40 site on ground floor.

I have got a sanction plan for stilt + 3 floor. Here what is stilt?

I already have electric connection here which has a small house. SO when i am constructing new house should i get new connection from Electricty board? If i have to then should i go for 3 phase connection or which type of modern connection will be good

I heard nowadays gas cylinders can be kept outside the kithcen and there will be copper connection for the same. Can anyone provide me more details on this?.

Any rough idea what will be the budget to construct 1000 sq feet house.

Thanks
btbda