An addition is usually a bigger investment, and more involved, than other renovation projects — so it pays to understand the value and the cost before you start.
What drives the cost
The type of space, the complexity of the project, the quality of materials and the size of the addition all affect the final cost. An upscale addition costs considerably more than a midscale one because of its size, finishes and materials; a second story adds structural work and more raw materials.
Typical ranges
If you are adding a midscale master suite to your Scottsdale home, expect to invest between $120,000 and $135,000 on average. An upscale master suite — such as a second-floor addition with room to rest and unwind — typically runs $250,000 to $275,000.
Other costs to plan for
Extra square footage can raise property taxes and insurance, and gated communities may have HOA fees or requirements. Check with your municipality, HOA and insurance agent.
Addition or casita?
A detached casita gives guests and family more privacy and is now allowed on single-family lots in most Valley cities under Arizona’s 2024 ADU law — see casitas & ADUs. For options and our process, see home additions.