Does my property fits for an ADU?

Doing site surveys on backyards and lots across the Bay Area, we look for a few important aspects or conditions about the property that can have an impact on the location, cost, and orientation of backyard homes:

Slope & Grade: From the rolling Los Altos Hills to the flatlands of Fremont, property lots across the Bay Area can vary greatly. Typically, the flatter the intended site for the accessory dwelling unit, the better. The flatter the area is to start with, the easier it is for a construction crew to level the ground to pour the foundation for the backyard building.

While we have worked with homeowners with less than ideal slope conditions for their ADU, it is helpful to keep in mind that these conditions can have a significant impact on your project budget. A significant slope can have a tens of thousands of dollar impact on the site preparation costs, while building on a hillside could require significant site work, drastic erosion control, and different foundation type than the typical slab-on-grade poured concrete foundation that is typically used.

While almost anything is possible with our custom approach to stick-built ADU construction, these conditions can add anywhere from ten to a hundred-plus thousand dollar cost to your project, regardless of the ADU company or general contractor you choose to work with.

Trees & Landscaping: While that large oak tree in your backyard great for a treehouse or shade from the summer sun, it can get in the way of your ADU plans. Cities vary in their treatment of protected trees, but common species that cities try to protect include California Redwood, Coastal Live Oak, Sycamore, and Elm, and others go by trunk diameter at chest-height for defining their protected trees. Removing or building around larger trees can vary widely; however, building near or on the site of existing trees often will require an arborist report and city approval of a tree protection plan. This can add some cost and complexity to your project, and we are here to help guide you through that process for your ADU.

Structures & Easements: Two common things we see in folks’ backyards are existing buildings and overhead power lines. Structures such as garages, sheds, storage units, and even outdated accessory dwelling units typically have to be removed for the construction of your new backyard ADU. Our general contractor partners help remove these obstacles – but it does help to know how large a structure needs to be demolished or removed, as well as whether the structure sits on old concrete that would need to be excavated.

While structures merely impact the scope of your ADU construction, easements such as overhead power lines can throw a wrench into your ADU plans. An easement is a right to use and/or enter your property without explicit ownership, such as the power company needing access to an electrical pole or water company needing access to a storm drain. You can check for easements in your property’s title report or deed, and also with the local city or county building and planning department of residence.

In the case of ADUs, an easement prevents you from constructing an accessory dwelling unit within the designated easement area on your property. The most common example we see is above-ground power lines at the front or rear of your property. If you see power lines and/or electrical poles in your back yard, there may be a utility easement. Having overhead power lines in your front yard or sidewalk is often an immediate blocker for any prefab ADU company that is hoping to crane the completed structure over your existing house; city and county utility companies won’t allow the risk.

Prefab ADU companies across the Bay Area have advertised quick construction times and lower sticker costs for their prefab homes and modular houses. We believe stick-built construction can be delivered at the same time and cost as prefab while opening up lots that wouldn’t work for prefab due to power lines or difficult craning situations.