ADU and Casita Building Services by Old Reliable
Arizona's updated ADU (Accessory Dwelling Unit) laws have made it more straightforward than ever to permit and build a guesthouse on your property. Old Reliable works with homeowners across the Valley who are considering a casita for family members, a private home office, or a rental unit that generates additional income.
As an experienced ADU contractor, Old Reliable operates as a design-build company, meaning they handle the entire process under one roof — from initial concept through to engineered plans and permit submission. They maintain a selection of stock size plans that serve as a useful starting point, though these are typically adjusted to suit tighter lots and individual requirements common throughout the Phoenix area.
Example ADU Floor Plans
Old Reliable offers a look at previous designs to help clients get a sense of what's possible. Two examples include:
- "The Classic" — A 24x24 layout totaling 576 square feet. Compact square designs like this tend to feel efficient and spacious when laid out thoughtfully. The rendering features board-and-batten siding, though materials can be substituted based on the homeowner's preference.
- "L" With Patio — This accessory dwelling unit offers 640 square feet of livable space along with an additional 100 square feet of covered patio, integrated into the main roof system. The interior follows an open-concept layout, with one leg of the "L" providing a degree of separation and privacy. Ample windows bring in natural light throughout.
All designs, dimensions, and proportions are customizable to fit specific needs and lot conditions. Old Reliable works with clients to finalize a design they're satisfied with before moving forward with engineering and permitting.
What Old Reliable Brings to the Project
Old Reliable has spent years working on home remodels, which means they bring practical knowledge of how to integrate a new structure into an existing property. This includes working around landscaping, utilities, and the space constraints that are common on Valley lots.
Their process includes:
- In-house design — Custom floor plans and 3D renderings so clients can visualize the finished backyard cottage or casita before construction begins.
- Engineered plans and permitting — Old Reliable manages the technical and administrative side, handling the paperwork so homeowners don't have to navigate it themselves.
- In-house carpentry crew — Rather than relying heavily on subcontractors, their own crew handles much of the build work, which helps keep timelines tighter and reduces delays.
Building an ADU or granny flat is increasingly seen as a practical way to add value to a property, whether the goal is housing for family, a dedicated workspace, or a rentable unit. Old Reliable's combined design and construction approach aims to simplify that process for Arizona homeowners.