Accessory dwelling units (ADUs) also known as guesthouses, companion units, granny flats or mother-in-law apartments, are separate housing units that can be attached to a main house or separated from it. An ADU has its own kitchen and bathrooms, meaning its tenants can be completely independent of those in the main house.
The number of new ADUs is on the rise, as homeowners see a great opportunity for renting out small units to cost-conscious renters. They’re also commonly used to house family members, like recent college graduates or doting grandparents, who want to be close but still autonomous.
The ADU may be small, but the undertaking is big. Just like any other building project, they require serious thought and planning before construction.. If you’re considering adding an ADU to your property, consider these five points first.
5 things to know before building an ADU
1. Zoning and building laws vary by municipality. Your city or town has its own zoning and construction laws that can vary significantly from those of the next town over, so be sure to read the regulations thoroughly. You may find that you can convert an existing shed or garage into an ADU, saving time and money down the road.
If you can’t find your city’s or town’s regulations listed here, then simply search for your official municipality’s website and look for information on planning and building. If all else fails, call and ask.
2. Some subdivisions and homeowners associations don’t allow ADUs. Your town may allow the building of an ADU, but your subdivision may not. Check first.
3. Architects can help you in the initial planning stages. Work with an experienced architect to draw up plans to submit to your municipality’s planning department to get the appropriate permits. An architect can help you integrate what you want with what you need.
When reading up on your locality’s building laws, you’ll likely discover restrictions on things like your ADU’s dimensions, required distance from property lines, general appearance and parking space requirements. Incorporate these in the initial design so you don’t have to make changes later.
Also consider people during this phase, specifically your guests or tenants, your neighbors and yourself. Will grandma or grandpa be living there? If so, add in senior-friendly design elements like ramps instead of steps. Will your neighbors object to an ADU that’s close to their property with windows facing them? If so, try skylights instead. Will you be happy with an ADU that blocks your favorite view or is too close to the main house? If so, reduce the size or change the location.
4. Building an ADU is a construction job like any other. You will need to submit plans, get permits and follow all construction regulations. Your plans will need to incorporate standards addressing fire safety, water lines, sewer connections, distance from lot lines and many other considerations. Working with experienced and reliable architects, engineers and contractors at this stage is crucial.
5. Building an ADU is often expensive. Ideally, you will make back your money through rent, if that’s your plan. But expect to shell out some serious money during the planning and constructing phase. Also be aware that you may find it hard to get a bank loan to finance your ADU construction.
Check out Avvo’s post for Zillow Blog for more legal advice on building an ADU.