Central Oregon’s Leading ADU Contractor

Accessory dwelling units add versatility and value to your property. Whatever your dream use is, our team designs and builds ADUs for lasting impact. 



A Scandinavian take on simplistic ADU living in NW Bend. This custom new construction project embraced ski chalet exterior aesthetics with premium fiberglass windows and vertical cedar siding.
interior Renton ADU, ADU contractor
Modern ADU, ADU contractor
Interior of ski-lodge style ADU, ADU contractor

Benefits of Building an ADU

Adding an ADU to your property can be a big undertaking, but one that pays off in multiple ways! We’ve seen some unique uses for these dwellings, from home offices and artists’ studios to rental units and mother-in-law suites. The possibilities are endless, and the main benefits are: 

Increased property value

More flexible living and working space

Efficient use of land 

Potential source of passive income

Private guest accommodations

What to Expect

When you choose Sierra James as your ADU contractor, our team will work to get every detail right—from conception to budget to construction. We pride ourselves on a fully transparent process that includes budgeting and cost data in real-time and a live schedule, so you always know what is happening and with whom. 

When working with us for ADU construction, our process is as follows:

1. Initial Phone Call and Visit

After the initial phone call to discuss project scope, we initiate a site visit to meet you and walk through your space. By the end of this visit, we’ll typically give a ballpark estimate on cost and timeline. 


2. Design and Costing Agreement

Once this is agreed upon, we’ll enter into a Design and Costing Agreement with deposit.

3. Design Phase

The design phase includes feasibility studies, defining scope, and architectural and interior design.

4. Costing Phase

Once the design is approved, the project enters the costing phase. Our Pre-Construction Manager sends Requests for Proposals, schedules onsite walkthroughs, and assigns allowance amounts. Once compiled, we’ll present the final budget. 

5. Permitting and Project Schedule

Upon budget approval, we’ll submit drawings to the planning department for permit (if applicable) and draft the project schedule. 

6. Construction

During the construction phase, your project manager’s priority is an open line of communication. During the entire construction process, clients have access to daily costs and schedules.

7. Final Walkthrough

With the last nail in place, it’s time to enjoy your new space! We do a final walkthrough to ensure everything is exactly as it should be.

Why Choose SJC As Your ADU Contractor

Our multi-talented team has decades of experience in their respective specialties. When entrusting us with your ADU construction, we combine our expertise with your goals to create something beautiful, functional, and durable. 

Sierra James Construction is built for excellence.