The reason why you are unlikely to be able to retain the existing garage door for your garage conversion are three fold.
Garage conversion keeping garage door.
Once the door is removed the resulting space needs to be filled in so that it both blends in with the rest of the house and provides a useful service to the new living space.
The biggest question facing most garage conversions is what to do about the garage door.
Transform your unused garage into a comfortable and functional living space by switching out the garage door for a sliding door.
Other homeowners replace the garage door.
Instead of only having the options of a closed garage door or open air using a screen made by companies like genius or lifestyle can make the garage convert instantly in to a screened in porch.
Or if you want to be able to use the garage for its intended use in the future you can keep the door as it is and lock it normally.
2 rain water can penetrate under the existing garage door making a unsuitable weather seal for a habitable room.
If your garage is large enough you may want to consider building a wall a few feet from the garage door.
This will allow you to keep the garage door on the outside while adding more insulation and soundproofing to the converted room.
The extra space between the new wall and the garage door can also serve as storage space if you add a door.
You can also install a garage door that either has transparent windows or glazed panels that let in light without reducing privacy.