Sulekha community - Advice from neighbors and local experts

I am looking to build duplex (or detached units, if possible) on a XXXXsf lot with XX ft frontage and XXX ft depth. Some specification outlined below - X. Each unit upto X4XX-XXXXst sf / X bed/2.X bath 2. Each unit 2-story/ X. Open kitchen living-room/ dining plan ( open plan) 4. Master bed / master bath on Xst floor/ Other bedroom rooms on 2nd floor X. Laundry connections can be in garage, with X. Standard room sizes with closet (In master the walk-in-closet should not open from bathroom, preferably open from bedroom) X. Each unit attached 2 car garage (preferred, but minimum X car garage) with 2 car driveway. 8. Bedroom should have split plan. The two bedroom on 2nd floor should not be on top of master bedroom I am open for your suggestions, ideas to keep up with the latest trends and to keep the cost as low as possible. The goal is the keep the totalcost down, by cutting odwn on unnecessary aethetic, but more functional and durable (long term operating cost low). I plan to hold these properties for a long term