Types of ADUs
Detatched
Detatched ADUs are typically new construction separate from the house and are often the first option people want to explore
Good for sound isolation and privacy
Requires the most amount of land
Requires the fewest changes to the existing house
Attached
Adding on to a house to create an ADU can work great on lots that still have room, but not enough for a detached solution
Requires fire rated construction between the main house and ADU
Placement is important to preserve privacy and identity
Will require modifying the existing house
Garage Conversion
Garage conversions are often one of the first options discussed, but they need to be carefully considered
Potentially the most cost effective
Plumbing can be complicated
Floor must be sealed and insulated
Storage for both main house and ADU must be addressed
Must modify the house for fire-rated construction separating the main house from the ADU
Above Garage Addition
Building above a garage is a great way to separate the main house and ADU using the garage as a buffer
Good solution where land is limited
Requires modifying the existing building
Fire-rated construction requriements can get complicated
Access and entry into the ADU can be a challenge
Attic or Basement Conversion
Sometimes the best solution is to convert an underused portion of the main home. The best approach for this is not always obvious
The most intrusive project type during construction
Success is highly dependent on existing circumstances and layout
Will most likely require a great deal of modificaiton to the existing house
Fire-rated construction for separation and support structure could be very complicated