Would need to see the elevation.

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.

There are no setbacks on the east and west so it would be unauthorised construction which I am sure you are aware of. You have tried to squeeze 3 bedrooms in a plot that could realistically only accomodate one bedroom. As a result there is inadequate natural light and ventilation for the central parts of the house and toilets. Nevertheless it would be better to avoid toilet in SW corner. Stairs could be east west orientation. Plinth to be atleast 45cm above the surrounding ground and the plot itself should be above the road.

The orange is actually interesting and many people are adopting a wacky and young look for their office. I will suggest you to break the monotony and NOT go for grey or warm wood colors in the office since these colors make the space dull. You cn go for matte white laminates on the cabinets. With black and white pattern paintings/decor.