ADU Example - Existing Structure

David's Spacious ADU Lot

Quick Facts

  • Neighborhood: Southeast
  • Type of ADU: Detached, Stand-alone
  • Square Footage: 760 Square Feet
  • Year Built: 1953
  • Owner: David Schmitz
  • Designer: David Schmitz
  • Cost: not applicable since the ADU already existed


David, an architect at engage:ARCHITECTURE, went through a different process than most to incorporate an accessory dwelling unit (ADU) into his property. In David’s case, the ADU was the first structure on the lot. He had lived in the ADU structure for seven years before he started work in building his primary dwelling, a showcase for his work as an architect, and his family’s current home. 

When David bought his property, the existing structure (now the ADU) was considered the primary dwelling unit. He always wanted to build a house from scratch and created a master plan for the property that included his future primary dwelling unit and a woodshop that would eventually serve as a buffer between the ADU and primary dwelling. As an architect, he had a good understanding of city codes and processes.

Aside from wanting to create a home from scratch, David saw potential in having both a primary dwelling and an ADU because he was able to earn extra income through renting out the ADU. In addition, when he bought the property, he envisioned that his parents might live in the ADU one day so that they could be closer to his family. 

From a sustainability standpoint, David likes that ADUs increase density, and in his case, that they have the potential to make use of the existing infrastructure and utilities in place. From David’s perspective, infill development is an efficient use of existing land, and can encourage more businesses to develop in a neighborhood to meet and support the needs of the additional housing.

David acknowledges that a down side for ADUs could be a lack of privacy because the ADU tenant might have to go through the yard, and if the lot is not big enough, then the space may feel crowded; however, David lives on a corner lot, and both the ADU and primary dwelling have their own driveway and carport to avoid a crowded space or lack of privacy. 

Since the ADU was already in existence when David bought the property, he could not speak as to if the ADU was built with sustainability in mind. He did, however, replace the windows in the ADU with more efficient ones. Most of his sustainable features occur in his newly built primary dwelling. Some of these sustainable features include a solar oriented design, air-tight construction, triple pane windows with different glazing types based on solar orientation, sun shading devices, a tankless gas water heater that is 96% efficient, all EnergyStar appliances, low flow plumbing fixtures, low VOC interior paint, a rain swale, and a rooftop vegetable garden over the existing shop he had built. 

As an architect, he spent a lot of time on the design and choice of materials. When asked if his master plan property with both a primary and a secondary dwelling unit met his expectations, he said that the master plan met his expectations and worked out the way it was supposed to. David is happy to have a primary dwelling that showcases his firm, and an ADU where his parents live and can be close to his family.

As advice to anyone looking to build an ADU, David encourages everyone to talk to a design professional. Design professionals can provide clients with new perspective that incorporate real world impacts of building a second dwelling on one lot. These professionals are also familiar with city codes, which make the processes run much more smoothly. Many people who are contemplating building an ADU are concerned about the small size of the dwelling, but a good design can mitigate these concerns.