Questions to Ask Before Signing a Room Addition Contract in Phoenix

Signing a contract for a room addition or ADU (casita) is one of the biggest financial commitments a Phoenix homeowner can make—and the fine print matters as much as the floor plan.

Verify the Contractor's Arizona Credentials First

Before you even read a contract, confirm the basics:

• ROC License: Arizona's Residential Contractors requires all general contractors and specialty trades to hold a valid Registrar of Contractors (ROC) license. Ask for the license number and verify it online. Unlicensed work can void your homeowner's insurance and create massive liability.
• Liability and workers' comp insurance: Request certificates naming you as an additional insured. Desert heat and rooftop work make job-site injuries a real risk—you don't want to be responsible.
• BBB and ROC complaint history: A clean record matters. One or two resolved complaints is common; a pattern of unresolved ones is a red flag.

You can browse verified local professionals in our room additions search for Phoenix-area pros as a starting point for building a shortlist.

Scope of Work and Permit Questions

What exactly is in writing?

Vague scopes like "addition per plans" are contract landmines. Push for specifics:

• Square footage, ceiling heights, window/door counts and brands
• Material grades (concrete block vs. wood frame—both are common in Phoenix, but thermal performance differs significantly in 110°F summers)
• Finish allowances with actual dollar amounts per line item
• Demolition responsibilities and debris removal

Who pulls the permits?

In Phoenix, permits for structural additions and ADUs are pulled through the City of Phoenix Development Services Department. The contractor should pull permits in their name—not yours. If a contractor asks you to pull the permit, walk away. That shifts legal accountability to you.

Ask specifically:

• Is a site plan and architectural drawing included in the bid?
• Who coordinates City inspections?
• What happens to the project timeline if permit approval is delayed (which is realistic; Phoenix review times vary by months depending on workload and project complexity)?

ADU-Specific Questions in Phoenix

Casitas and detached ADUs have their own layer of complexity in Maricopa County and within Phoenix city limits.

If you live in an HOA—and most of Phoenix's suburban neighborhoods do—get written HOA architectural approval before signing the contract. Some HOAs prohibit detached casitas outright, regardless of city zoning.

Payment Schedule and Lien Protection

This is where homeowners most often get burned. Ask these questions word for word:

1. What is the draw schedule? A fair structure ties payments to verified milestones (foundation poured, framing inspected, rough-in approved), not arbitrary calendar dates.
2. What percentage is due at signing? Arizona law limits deposits for residential work over a certain threshold—anything over 33% upfront for a large project is a warning sign.
3. Will you provide lien waivers from subcontractors? If your GC doesn't pay their electrical or plumbing sub, that sub can place a mechanic's lien on your property even after you've paid the GC in full.
4. Is there a retention clause? Holding back 5–10% until the final punch list is complete is standard and protects you.

Timeline, Weather, and Force Majeure

Phoenix's monsoon season (roughly June through September) is not a polite suggestion—it can halt exterior work, delay concrete pours, and create real scheduling disruptions. The contract should address:

• Projected start and substantial completion dates (not just "estimated")
• How weather delays are documented and communicated
• What constitutes a legitimate change order vs. scope creep the contractor should have anticipated
• Penalty or incentive clauses, if any (common on larger projects)

Ask how the contractor handled monsoon-season delays on a recent project and what the outcome was for the client.

Warranty Terms to Review Carefully

Arizona's implied warranty of workmanship exists, but written warranties give you clearer recourse. The contract should spell out:

• Workmanship warranty: One to two years is typical for residential construction
• Materials warranty: Often pass-through from manufacturers; get documentation
• Who handles warranty claims: The GC directly, or are you chasing individual subs?

What Happens If Things Go Wrong?

No one signs a contract expecting a dispute, but include these questions anyway:

• Is there a mediation or arbitration clause? (These can limit your ability to sue.)
• Does the contractor carry errors and omissions coverage?
• What is the process for terminating the contract if work quality is unacceptable?

The Phoenix business directory on Saguaro List can help you compare multiple contractors and read local reviews before you ever sit down at the table.

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A room addition or casita is a long-term investment in your property—and in Phoenix's real estate market, a well-permitted, well-built ADU can meaningfully increase home value. Take the time to ask every question above before you sign. If a contractor resists answering any of them clearly, that's your answer.