Stand Alone Unit-small
Works well in large yards and no setback issues. If a small unit meets your needs this can be a relatively low cost solution
Attached to Existing garage
Works well in large yards and parking can be in the adjoining garage
Only works if parking is provided in another location or you build a separate garage to provide the lost parking spaces.
Attached to rear of house
Works well in many cases, easy access to house and can be used as family room when needed.
Second Floor Addition
The most expensive option to build. Works well for houses that have little yard or you do not want to use up all the yard area. Stairs take up a lot of space so this is not the best option for limited square footage.
Stand Alone Unit-Large
Most areas have a 700-800 square foot limitation but it can be designed creatively to look like a separate house.
Two Story Unit
This type is usually done as a large room addition with a separate entrance but still connected to the house.
Between house and garage
Nice way to connect parking and utilize the space between your house and garage.
Built above its own garage
This option is difficult to build in most cities because of height restrictions but it is possible in some areas.
Added as a hobby room
This unit was added as a non-habitable hobby room or basically a storage room. Less cost for permits but you are not allowed to sleep in it and no bath is permitted.