In recent years, a growing number of homeowners are building accessory dwelling units (ADUs) on their properties. And it makes sense. ADUs provide an excellent way to accommodate family and invest in your property in the long-term. That said, building a home in your backyard represents a significant investment, and you shouldn’t trust this type of project to just anyone who promises it’s easy to deliver. With all the horror stories about dishonest contractors and subpar work, how do you select an ADU contractor who will do the job well? Here’s 5 key characteristics to look for.

1. Experience in your community

As a rule of thumb, the longer a contractor has been in business, the more likely it is they will do a good job for you—but there’s even more to consider. Don’t just ask how long the contractor has been in construction, or even how many ADU projects they’ve done; find out how long that contractor has been working in the local area. Ask about similar projects and how active they are in your community. The more invested a contractor is in the community, the more likely they have built strong relationships with reliable suppliers, subcontractors, craftsmen, and local city officials.

2. Working knowledge of local codes and ordinances

If you’re investing in designing and building an ADU that requires permitting, you need to assure your local contractor of choice is has a deep familiarity with building codes, permit requirements and other legalities of the various cities and counties in your service area. We can’t overstate this. Failing to comply with city ADU regulations can result in hefty fines and sizeable delays. A good ADU specialist will make sure the proper design requirements and best practices are in place. That way you won’t need to worry about permits that won’t comply with local ordinances, all before getting started.

3. An established process

Choose a specialist. A partner that’s done it all before. Remember, you likely haven’t built an ADU before. And, designing and building an ADU is challenging. You wouldn’t give yourself a root canal right? A good partner will have a proven, well-mapped process, as well as milestones in place, to manage your project and assure it gets done right. Ask about your contractor’s process.

4. Open communication

Does the contractor welcome your questions? Are they cagey? Not a good sign. Your ADU builder should be transparent. A great ADU builder will be honest, share expectations about hidden costs, completion times, possible pitfalls, challenges, and opportunities up front. Trust is one of the most important elements of a great customer/contractor relationship. A great partner will nurture an open line of communication with you from concept to warranty. You should always feel free to ask questions, express concerns or raise issues, and you should expect a timely response to inquiries.

5. Customer stories

In short, always ask for information about a similar project to you own, and references from any ADU contractor you are considering. Did the client have a good experience? How was the craftsmanship? Did the project stay at or under budget? A contractor with an excellent reputation will gladly give references on request.