why do u want two and a half stories. do u mean 1/2 of the story is below ground level or two levels with 1/2 story to the attic. there is a height restriction to how high a building can be built. an attic is very closaphobic and not recommended. if the 1/2 story is below ground, then u have to pay attention to flooding. i think three stories above ground is better than the two proposed design if there is no height restriction. also u have to worry about front yard e and back yard and side yard restriction. i think reinforced concrete is better than wood because wood invites termites. u can have slope roof or slightly inclined roof without ponding. plumbing is the most expansive gadgets in a house. u should design the kitchen and bathrooms on the second floor be above the first floor. according to principle of feng sui, the kitchen should be located on the side middle of the house with window on the side. the bedroom shouldn't have door opens to the bathroom. a curve stair from front door with access to the second floor is recommended. u need a structural engineer to design the reinforced concrete rebars. u need to follow the local building code or the national building code for water heater, gas furnace. gutters to drain storm water plus sanitory pipes for sewers are needed. telephone and electricity must provided by the city. finally, u need a development permit depending on the zoning by law before u can proceed with design.