I was hoping for some advice regarding a building I am looking to construct.

I am looking to build on a land measuring 100ft x 50ft.

my ideal construction if possible is to construct:

main house- at the front of the land 3 bedroom bungalow with penthouse (making it four bedrooms),

back of the main house- 1 two bedroom flat, or if I can fit 2, 2 bedroom flats that would be great

a generator room to hold a "heavy duty generator"


with regards to the main building I would prefer the following
master bedroom to be an en-suite and all other rooms to be of a decent size
front porch/balcony
spacious kitchen
living room with a separate dining area

penthouse to be an ensuite
Juliet balcony, with Bi fold doors

the other alternative I have in mind is to build as mentioned above, but without the penthouse and only 3 bedrooms in main house

I am curious to know if penthouse option is realistically achievable? if so estimate cost and length of time to finish

or

if I should stick with the alternative option? cost ? and length of time to finish?

any advice will be greatly appreciated