Costs of additions - small house, non-standard floor plan (living, kitchen)

[paperpile]

Our house is very small and has an unusually small floorplan with not much space to give. I am very curious about the cost of standard house additions such as an attached garage, another room on the ground floor, small addition on the top floor, etc...

We are thinking of adding a very small garage, and a small room on each side of our house. Just curious what the rates in NJ are on average. Any hints, experiences, please share! Also, would you rather keep one bathroom in the house and have more space, or figure out a way to add that 1/2 bath, perhaps sacrificing kitchen space. Our house has three problems, no formal dining room, no attached garage, and one bath with no more room to add anything inside.

Trying not to think too outside of the box, because one day we will have to resell. We also thought of getting rid the front door, and instead enlarging the side door to give the living room more space, but we don't know if there are any regulations in NJ saying that a house must have a door in the front. I know there need to be two doors for fire regulations, I hope the patio door would count as one.