Are you thinking about building an accessory dwelling unit (ADU) but aren’t sure how to begin?

Building an accessory dwelling unit can be a huge undertaking. However, it’s a worthwhile project, as having a second dwelling space can offer a lot of benefits for you and your family. Before you begin construction, there are some things you need to know.

Check out this guide to learn everything you need to know about building an accessory dwelling unit.

What is an Accessory Dwelling Unit?

First things first, what exactly is an accessory dwelling unit?

An accessory dwelling unit, also known as an ADU, is a secondary housing unit that’s on the same lot as a single-family home. For a structure to be considered an official accessory dwelling unit, it must contain all of the same amenities that are found in a primary dwelling.

This includes a kitchen, sleeping area, bathroom, and storage area. For your structure to qualify as an ADU, it must also conform to all state and local building regulations, planning codes, and energy codes.

ADUs are known by some other names, including granny flats, mother-in-law suits, in-law suits, secondary units, and backyard cottages.

Understand the Different Types of ADUs

Before you build an accessory dwelling unit, you first need to understand the different types available. Here are the different types of ADUs:

Detached ADU: This type of ADU is a separate, stand-alone structure that is independent of the primary dwelling unit and includes a full range of amenities.

Attached ADU: An attached ADU serves as an addition to the primary home.

Garage Conversion ADU: A garage conversion ADU turns the existing garage structure into an accessory dwelling unit. A lot of times, this can save you a lot of money, as you don’t need to build a whole new structure from scratch.

Interior ADU: This type of ADU exists within the interior space of the primary dwelling unit. It’s also sometimes referred to as a junior ADU.

Understand Your Local ADU Regulations

Before you begin to build your ADU, you also need to understand your local regulations. Each city has different property development standards.

Before building, you’ll need to know your area’s laws in regards to the density units that are allowed for a given property. Your ADU will need to fall within these density constraints.

Some areas also have height restrictions, and some units need to be within a certain distance from the primary dwelling unit. Some places also require you to provide off-street parking for your accessory dwelling unit.

If your unit is close to public transportation systems or if it’s in a historically significant district, you may not need to worry about this. Speak to your local government officials to make sure you’re building the unit within your city’s regulations.

If you’re building your accessory dwelling unit in California, you can check out to learn about local laws.

Consider Why You’re Building the ADU

Another important thing to take into consideration is your reason for building the ADU. Here are some of the primary reasons people build ADUs:

  • To rent out to tenants or vacationers so they can make some extra income
  • To have extra space for people to bunk in when friends and family members come to town
  • To serve as a permanent living space to close family members or friends

The reason you’re building an ADU will have a lot of influence on how you construct it, so make sure to think about your “why” before you break ground.

For example, if you’re building an ADU to rent out to people you don’t know, then you’ll want to ensure that the space has extra privacy. On the other hand, if you’re building the ADU so you have a space for your family members to crash in when they come to town, then you don’t need to worry so much about keeping things private.

Consider the Cost

Cost is another very important factor to consider when building an ADU. The cost to build an ADU can vary greatly depending on where you live, the materials you use, and how big the unit is.

Generally speaking though, you can expect to pay anywhere from $75 to $650 per square foot to build your ADU. Of course, you also need to think about the maintenance costs.

As we mentioned earlier, your ADU needs to have all of the same amenities as your primary dwelling. This means you’ll need to hook up water, gas, and electricity and pay a monthly utility bill.

Of course, if you plan to rent out your ADU, you can include these costs in your monthly rental statement.

Consider Fire Regulations

Before building an ADU, you also need to consider your local fire regulations. Some places require you to have a sprinkler system installed within the unit, while others may just require you to have a fire extinguisher nearby.

As we mentioned before, you can speak to your local government officials about the regulations in your area. Either way, it’s a good idea to install a sprinkler within the unit in the event of an emergency.

Are You Ready to Build an Accessory Dwelling Unit?

Now that you’ve read this guide, it’s time for you to build your own accessory dwelling unit.

An ADU can be a great way to add more space to your home without upgrading to an entirely new house. Be sure to check back in with our blog for more tips and tricks related to home building projects.