Why settle for prefab? Here's why a custom ADU design is the way to go.

When it comes to building an accessory dwelling unit (ADU), there are two main options: choosing a prefabricated unit, or investing in a custom ADU design. While prefab ADUs seemingly offer a quick and easy solution for those seeking an additional dwelling space, they are not the best fit for everyone. Here are a few reasons why a custom ADU design might be the way to go to achieve your ADU dreams.

An ADU tailored to your needs and preferences

A custom ADU design allows you to tailor your unit to your specific needs and preferences. With a prefabricated ADU, you are often limited to a set number of design options that may not fit your unique needs. A custom ADU design, on the other hand, allows you to work with a designer or architect to create a space that is exactly what you need and want. Having worked with hundreds of clients over the years, we love taking client’s ideas and crafting beautiful solutions. Even with our pre-designed ADU plans, we offer customization services to adapt the designs to client’s needs.

An ADU that fits your property

One of the biggest downsides to a prefab ADU is that it may not fit your property. Because these units are pre-designed, they may not work with the specific layout of your property, potentially leading to difficulties during installation. Features such as trees, existing structures, site topography, or adjacent power lines or other utilities could hamper the ability to install a prefabricated ADU. With a custom ADU design, you can ensure that the unit fits your property and takes advantage of site features, orientation, views, and other strategies to seamlessly integrate the new unit to your property.

Materials, systems, and finishes selection

While prefab ADUs are often marketed as a more affordable option, the materials used in their construction are typically pre-selected by the company fabricating the unit. There is limited opportunity for you to pick the materials, finishes, fixtures, and systems that will define the look and feel of your ADU. A custom ADU design allows you to choose the materials, leading to a design that aligns with your style. Plus you have the opportunity to focus on picking materials for durability, quality, and sustainability.

An environmentally friendly ADU

Custom ADU designs can be more environmentally friendly than prefab units. One of the biggest advantages of a custom design is it can be tailored to respond to the site, climate, and take advantage of active and passive strategies for sustainable design. Orienting the ADU’s roof towards the sun and adding a PV system could make your ADU a net-zero energy home. Designing the unit to get natural light and ventilation can reduce energy usage further and create a healthy indoor environment. Because you are able to choose the materials, systems, and features of your unit, you can select high-performance, environmentally friendly options such as energy-efficient appliances, solar panels, solar hot water systems, and sustainable building materials. This can lead to a lower environmental impact and reduced energy costs over time.

Custom design doesn’t have to cost more

Many prefab ADU companies will advertise that their units are more affordable than a custom solution. On the surface this could look like it is true. The price tag on many prefab accessory dwelling units are very attractive. However, it is important to consider the full costs of adding an ADU. Often prefab ADU prices don’t include things like site prep, getting utilities to the ADU, concrete work, pathways and landscaping, permitting fees, and other important aspects of adding an ADU. At the end of the day, the size of the unit, quality of materials selected, and the finishes, fixtures, and systems chosen for the ADU are the biggest determining factor of project cost. A custom design could come in at the same overall cost as a prefab unit and in some cases could even be cheaper. We have designed many nice ADUs that are comparable in cost to the prefab designs we see on the market.

In conclusion, while prefab ADUs can be a quick and easy solution for some, a custom ADU design is often the better option. With a tailored design for your taste and property, ability to select all the materials, and the ability to design a great accessory dwelling unit within your budget, a custom ADU is a smart investment in the long run.

We would love to help you achieve your ADU goals. whether through a fully custom design or by starting with one of our pre-designed ADU plans and adapting it to meet your needs. You can check out our plans for sale here, or contact us if you are thinking about doing a custom ADU.

Custom ADU interior with exposed wood structure and a series of skylights to bring in lots of natural light.

Exterior rendering of a custom ADU design. The simple form makes for an affordable project while the natural cedar siding, large sliding glass doors, and metal roof make for a high quality and beautiful home.