With these circumstances you will want to consider filling the bottom of the garage door opening with a curb that will keep water out of the converted.
Level garage floor conversion.
The designers of this luxury annex installed a high level entrance with led lit.
Lay the joists on edge across the width of the floor.
The slab may well be sloped toward the garage door or a floor drain.
How to raise garage floor for living space.
Normally garage floors are about 8 inches below the general house level.
The taller the joists the more room for insulation and warmth of the floor.
The garage conversion requires the floor to be raised to match the house so first job is to build a suspended floor.
Install either 2 by 2 2 by 4 or 2 by 6 joists over the garage floor depending on how much room you have floor to ceiling.
When converting a garage space into a living area installing a framed wood floor offers an opportunity to add insulation from the cold concrete slab access for electrical circuits to any interior walls being planned and effectively provides a level floor platform over a standard garage floor that can be sloped 4 to 5 inches from front to back.
Time to get building again.
Nail cross blocking boards to hold the joists together every 4 feet.
A typical garage sits on an uninsulated concrete slab which may be several inches below the floor level inside the house.
Adding levels to a garage conversion creates the illusion of more space just like this ingenious split level layout.