ADU Example - Converted Garage

Stefan's Converted Garage

Quick Facts
  • Neighborhood: Harlow
  • Type of ADU: Detached, stand-alone unit
  • Square Footage: About 790 square feet
  • Year built: 2011
  • Owner: Stefan Aumack
  • Designer: David Schmitz from engage:ARCHITECTURE
  • Builder: Stefan Aumack
  • Total Cost: About $30,000 (excluding permit fees)
Photo of Stefan Aumack's SDU living room. 


Stefan had room for more than one residence on his property, and in 2011 decided to convert his stand-alone garage into a accessory dwelling unit (ADU). His existing garage already had its own driveway and was separated from the primary dwelling, so it made sense to transform the garage into a second formal living unit. Stefan and his family can rent out the ADU, which they currently do, and use the extra money to supplement their income. While not the main reason that Stefan built his ADU, he said that long-term, the second residence could be used for his mom, should she decide to eventually move in. 

Stefan hired David Schmitz from engage:ARCHITECTURE to aid in the design process. One of Stefan’s goals in building his ADU was to use the existing framing and add as little new material as possible. David worked with Stefan to find a way to use the existing framing of the structure, including trying to fit the old structure of the doors and windows into the new ADU design. Stefan said that using the existing framing was the biggest challenge in building his ADU. It was difficult to make the existing framing fit the ideal vision for the new space.
Photo of Stefan Aumack's SDU kitchen.

The ADU that David and Stefan worked to create has several sustainable features. Stefan highlighted the design of the ADU as a sustainable element because he worked to use the existing framing and roof structure, and minimized the use of unnecessary materials. In the design, David and Stefan worked to minimize northern exposure glazing so that the ADU would not lose a significant amount of heat. Stefan’s ADU also includes a tankless hot water heater. 

When asked if his ADU has met or exceeded his expectations, Stefan said that his ADU has exceeded his expectations. As he built his ADU with sustainability in mind, he was happy that he could maximize the full potential of the property to create a nice living space, while using the existing framework of the structure already in place. 

For Stefan, a good design was the key to a successful ADU. So what’s his advice to anyone wanting to transform a small space into a livable ADU?

“Hire a good architect, and spend the time to get the design right.”