bht bht mubarik ho. Allah naseeb achay kary, Aameen!
Please do consult a suitable architecture and then start construction. Don't rely on these old "ThaikayDaars" as they don't have the competence to tackle this modern architectural requirements.
I am saying this with the experience. For the time being, may be you'll think and that "ThaikayDaar" will also say that he'll charge less than a certified architecture and build the same thing but reality will be totally different. Any miscalculation or wrong measurements will show its effect in just within five years, then nothing can be done.
This is your Hard-Earned money and will be hardened along with the concrete/cement in your house. This is not a LEGO blocks that you can take apart and change what you don't like.