Unpermitted ADUs create real risk at sale, refinancing, and with insurance. We manage the complete legalization process — as-built documentation, city permits, required corrections, and final inspection. Detailed written quotes. No surprises.
An unpermitted ADU is any residential structure — converted garage, backyard guest house, basement apartment, or detached unit — that was built or converted without obtaining the required city building permits. It may be a quality structure that's been occupied for years, but without permits it carries significant legal and financial risk.
Perris has a significant number of unpermitted structures from the city's rapid growth period in the 1990s–2000s. The city has streamlined its legalization pathway in line with California's ADU mandate.
Three situations make unpermitted ADUs a serious problem:
Legalizing proactively — not under deadline pressure — gives you control over the process and typically produces the best cost outcome.
Here's exactly how we handle unpermitted ADU legalization in Perris:
Inspect the existing structure and document all current conditions — structural, electrical, plumbing, and code compliance gaps.
Architect prepares documentation of the structure as it exists — required for Perris's retroactive permit application.
We identify and cost every gap between current condition and California/Perris code requirements.
Complete submittal to City of Perris with all as-built and compliance documentation.
Required upgrades completed — typically egress, electrical, insulation, smoke/CO, weatherization.
City inspection, Certificate of Occupancy, legal ADU status achieved.
The most common code gaps we find in Perris unpermitted ADUs:
We identify every gap during the initial assessment and include all correction costs in our detailed written legalization quote.