Every plan listing includes a construction cost estimate provided by the designer. These are rough estimates and can vary dramatically depending on current construction costs (materials, labor, etc.), your location in the state, and your site conditions. If you have a flat site with a lot of open access for equipment, easy utility hookups, and no unexpected surprises, your construction costs will be significantly lower than if your site is on a steep slope and requires extensive excavation, utility hookup work, etc.
Overall, factors that affect construction cost include, but are not limited to:
- Construction materials
- Appliances
- Finishes
- Labor
- Site conditions
- Local requirements
We recommend using a rough placeholder of $250-$550 per square foot, including construction and other costs (design, fees, etc.), depending on the relative costs in your area. The actual number can vary and depends on many factors. Also consider that many costs like foundation, and kitchen and bathroom work only increase slightly for larger ADUs. Kitchen costs will range from $25,000–$50,000 with each bathroom ranging from $15,000–$25,000. If you anticipate anything unique about your project (like high-end finishes, a sloping site, or a highly-customized design) then your final amount will likely be higher than the per square foot placeholder recommended above.
See this article for more information about costs associated with plans
