Navigating the World of ADUs - Page 2

Most ADUs are single story, and built in the back half of the lot, where they are less visible, a minimum four feet away from the property line. If you're building a detached ADU, says Klopf, you will need to get a property or land survey performed by a land surveyor, and get it approved. "It's a critical document that lets us know where we can place additions or separate structures."

"One thing homeowners don't think about," Klopf adds emphatically, "is that their fence line may not be their actual property line."

A successful ADU design takes into consideration that the new structure does not impact the aesthetics and livability of the main house, infringe upon the privacy and views of surrounding neighbors, and become incompatible with the neighborhood at large.

Another concern is the parking situation that may be brought on by the ADU's occupants, says Cline, "especially if it is used for more than one person, or if it's a home office used to meet clients."

Relating the ADU to the main house is a big part of the architect's service, and is critical, Klopf points out. "Aesthetically, we make an effort to keep the ADU appropriate stylistically with the language of the main house."

"Our primary concern from a design standpoint is to not copy the Eichler [main house], but be compatible, and respect the existing house and the space between it and the ADU," adds Cline, whose output includes several intriguing ADU presentations, including a unique 'glass cube' design.

The time needed to build your ADU will vary with each builder, but "it will take about as long as to build a house, since it's basically a miniature house," Klopf says. "In this [Bay Area] construction market, from ground-breaking to completion could be 9 to 12 months. There is also design time required before construction."

Cline estimates ADU building costs in the Bay Area to be in the $500-550 per square foot range.

In order to guarantee the best results with an ADU project, consult professionals who are in the position to help: a financial planner to appraise your budget in conjunction with the planned building; a realtor to assess if investing in an ADU makes sense tied to renting and/or re-sale plans; and a general contractor to assist with estimating building costs at the front end.

And, as both Klopf and Cline would agree, an architect should be consulted to ensure a successful ADU design—one that fulfills the owner's goals and needs and is compatible with the main house as well as its surroundings.

• For additional information on ADUs, refer to the 'Accessory Dwelling Unit Handbook,' a PDF-download guide issued by the State of California Department of Housing and Community Development.