There are several types of accessory dwelling units that you have to choose from. You can learn more about your options by clicking here.

What Are the Main Types of Accessory Dwelling Units?

Imagine you have unused space in your home. Maybe it’s in the basement or above your garage. Maybe it’s a shed in your yard that you never use.

By turning these spaces into accessory dwelling units or ADUs, you could earn some extra money for yourself. But what is an ADU?

Accessory dwelling units are living spaces that are separate from your main house. You may also know these as inlaw suites or guest houses. 

These can be used to house family members while still giving them privacy. They can also be rented out both short-term and long-term. 

There are many kinds of accessory dwelling units that you can have on your property. However, you should check the laws of your area before building one, since some places have ordinances controlling how these are designed. The design of your home may also impact what kind of accessory dwelling unit you can build.

This guide will help you choose the best accessory dwelling units for your property. 


These are essentially separate apartments built in the basement of an existing single-family home. These kinds of ADUs offer a fair amount of privacy. Unless your basement is unfinished, then these will be the cheapest and simplest to build.

A finished basement can be easily converted into one of these with a few changes. In most states, you must have a separate HVAC unit. It should have its own kitchen and at least one full bathroom.

These ADU options should have their own separate entrance from the main house. In some areas, it’s illegal for this entrance to be on the front of the house. 

You should always check your state and county’s laws before turning your basement into one of these accessory dwelling units. The building codes will be different in each region. For basement dwellings, these will usually regard the amenities that the dwelling offers or ceiling height.


A detached accessory dwelling unit is going to offer the most privacy. These are smaller dwellings that share the property with the main house. 

They are usually about the size of the popular “tiny house” that some people are living in today. However, they should not be confused with tiny houses. This website does a wonderful job explaining the difference between the two.

Detached ADUs are perfect to use as rentals since they are separate from the main house. Tenants can come and go freely without disturbing the residents of the main house or their neighbors. 

These dwellings may be subjected to stricter building codes since they are completely separate dwellings. Some areas require that the detached unit be similar in style to the main house, for example. This is so that the appearance of the neighborhood remains consistent, so this is most common in neighborhoods with Home Owners Associations.

Above Garage

These dwellings are among the most common types of accessory dwelling units. These sit above the garage, separate from the main house. This provides the same amount of privacy as a basement-dwelling if not more. Depending on how these dwellings are designed, tenants coming and going may cause some disruption to the residents of the main house. 

These are usually built as additions to houses or detached garages. These can be expensive to create. You often will need to extend water and electricity from the house to supply these ADUs as well as building a whole new area above your garage in some cases.

These are usually very small. This means that they work well for single people or couples with no children. They also work well as short-term rentals especially if they are above a detached garage. 

Once again, you should check your local laws to ensure that you’re dwelling will be up to code before you start building. Otherwise, you could be hit with large fines later.


An attached unit is going to look similar to townhouse units. They are small units that sit on the ground level attached to the side of the house. This creates the appearance of two front doors, which isn’t allowed in some areas of the United States.

These are going to give as much privacy as any other apartment or townhouse would. Tenants can still come and go without bothering the residents of the main house much. This makes them a good choice for renting.

These are expensive to build because you have to add an extension to your home. Oftentimes, you can extend the existing water and electricity from the main house into the extension, which saves a little money. However, the more work needed to build the extension, the longer it will be before you’re reimbursed for your investment.

Garage Apartment

Garage apartments look similar to attached accessory dwelling units. The main difference is that these are converted from an existing garage. 

These are among the cheapest ADU options to build because it doesn’t require new constructions. You can often extend the electricity and water from the main house to supply the ADU, which can also save you some money. 

These are going to be very small, and offer just as much privacy as many other accessory dwelling units. So these are also good to rent to single people or couples without children. Tenants can still come and go as they please with usually minimal disruption to the main house residents. 

The one drawback to these is that they take away your garage space, so you will need to find somewhere else for you and your tenants to park cars.

Start Building Your Accessory Dwelling Units Today

There are plenty of ways to set your property up for accessory dwelling units. They are a good way to earn extra money from renters or to keep family members close. Go ahead and get started on your ADUs today!

Be sure to check out your local laws regarding building codes and permits before beginning working on your new ADUs. Renters and family members will thank you forever for having their own space on your property. 

If you enjoyed this article be sure to check out our other lifestyle articles as well!

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