ADU Design Ideas to Increase Your Property Value

Last Updated on July 25, 2023 by support

Small blue ADU

There is no better time than now to consider adding an accessory dwelling unit (ADU). With many working from home, the need for extra space for work or spending time with loved ones is steadily increasing. This is why people are looking into ADU design ideas.

You can discover which ADU design works best in your plan and for your property. There are ways to build an ADU inside your home, attached to your home, and one that is a separate building.

No matter which design you choose, you can bring one or more of these benefits to your home.

Benefits of an ADU Designed for the Homeowner

An ADU Adds Usable Space

Whether a converted basement, above garage, remodel, or detached tiny house, an ADU adds square footage to your living space. The average size of ADUs ranges from 450 square feet to 1250 square feet. That amount of space is useful for a variety of purposes, from a home office to a place for older parents or your recent college graduated kid to stay.

It’s best to check local ordinances for how large you can make your ADU (check out Tucson’s ADU ordinances.) The size changes from place to place, with some having a minimum size requirement too.

Flexibility in the ADU Design

Not only can an ADU fit almost any purpose, but it can also change at any time to suit your needs. An ADU can be a short-term rental part of the year and open to visiting guests and family the rest. It is also possible to have an ADU designed as a yoga studio during the day and available living quarters at night.

An ADU Adds Value

Dark blue ADU with patio

ADU space adds overall value to your property. How much, exactly, depends on the square footage or the type of room.

The average value added per square foot ranges from $350 to $700. Homeowners average a 30% increase in home value for homes with an ADU.

As long as you follow city ordinances for things like the number of people in your home or square footage allowed, you can do with your space what you want. That includes renting your ADU as a living space, workspace, or studio. Potential rental income is another source of added value. 

Lastly, you can’t put a price on the ability to work from home or have family stay with you long term. It might initially be costly to convert a space in your home or build one out back, but it can be worth it to live life the way you want with the people you love. 

Benefits of an ADU for the City

While homeowners may see it as a way to earn money through increased property values and rental income, the city considers an ADU a way to save money.

An ADU on your property adds flexible, affordable housing options at no cost to the city. This is because the city doesn’t have to zone for improvements or construct new buildings to increase housing options. An ADU also adds housing options to the neighborhood without changing the layout or character.

ADUs also reduce the city’s environmental footprint compared to new full-size homes. While ADUs can range up to 1200 square feet, this size is still small compared to the average single-family home. Smaller rentals tend to be more environmentally efficient and use less energy.

ADU Types

ADU design ideas include finished attics

You can design your ADU to meet most any of your needs or wants. There are several different floor plan categories and ADU design ideas to fit your needs, including:

  • Internal 
  • Attached
  • Detached
  • Conversions
  • Prefabricated


Finished basement ADU

An internal ADU refers to any dwelling space that is inside your home. Some homes are big enough to turn extra rooms and suites into rental housing. Homeowners can convert unfinished basements and attics into suites for guests or renters.


An external ADU refers to more traditional spaces such as bonus rooms, grandma suites, etc., that remain attached to the home. This can include a garage conversion. 


A modernly rustic ADU

Detached ADUs remain separate from the main property, with separate entrances. It is possible to convert in-law suites, detached garages, pool houses, and storage buildings into living or working spaces. In many cases, it is possible to build ADU spaces above detached units. 


A conversion refers to a change in an existing space’s purpose. A basement typically meant for utility purposes such as doing laundry or storing wood can easily convert to a studio, work, or living space.

The biggest benefit is that converting previously unfinished areas into living spaces, offices, or a different bonus room adds value without adding square footage to your home.  

Prefabricated Floor Plan

Adding a prefabricated structure to your property is one of the easiest ways to add value. It is also one of the least expensive. A variety of prefabricated designs and floor plans already exist, from single apartment settings to one-story work and office studios. 

Cost of an ADU

Wood ADU

The cost of these ADU design ideas varies depending on whether they are new builds, conversions, detached, or attached. 

Prefabricated ADUs are the least expensive option for adding property value. While they have many design options, some homeowners prefer to build new or to work with what is already on the property. Conversions are also relatively inexpensive compared to building new or making additions above an existing space.

The most expensive option is building new or adding space above a building that won’t easily accommodate the addition. Consider speaking with qualified contractors before taking on these builds. Attempting an addition without careful consideration can be disastrous if something goes wrong.

Contact Frei Remodeling & Construction

Frei Remodeling & Construction has been a family-owned business in southern Arizona since 1962. We believe in and strive for honesty, dependability, timeliness, and quality over quantity. With 60 years of experience under our belts, we have the expertise to help our customers design the space of their dreams. 

Contact Frei Remodeling & Construction in Tucson, AZ, by filling out our contact form. Then we can start building the ADU that will change your life for the better. 

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Joe Frei

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