26 Issues Found Including Critical Seismic Anchorage & Accessibility Violations
Wood pad foundations in Seismic Design Category D, no accessible route to entrances, and incorrect HUD pre-emption claims—surfaced before permit submission.
The Project
A manufactured/prefab ADU project in California located in Seismic Design Category D. InspectMind reviewed the drawing set and identified critical deficiencies in seismic anchorage, fundamental accessibility violations, incorrect claims about HUD pre-emption of California codes, and extensive document coordination errors between floor plans, elevations, and site plans—issues that would have caused immediate permit rejection and potentially dangerous construction.
Sample Findings
Foundation uses wood pads on ground with 1/4" self-tapping screws. SDC D requires positive mechanical anchorage per CBC 1604.4 and AISC 341—structure could slide off foundation in earthquake.
Free-standing landing supported by only three 4x4 posts with non-moment-resisting bases. A rectangular assembly on three points is geometrically unstable under lateral loads.
Location map shows one urban block location. Site plan shows property at a completely different location with different neighboring parcels—two entirely different geographical sites.
Both entrances accessed via stairs only. CBC Section 1117A.3 requires ground-floor units to have accessible routes—steps are prohibited on accessible paths.
Notes claim "ALL MH PRE-EMPT CALIFORNIA REQUIREMENTS." HUD pre-empts unit construction only—site installation, fire protection, and accessibility still follow CBC per Section 420.1.
"ADU WILL NOT HAVE SPRINKLERS" contradicts CBC 903.2 and conflicts with scope noting "water tank for fire suppression system."
Issue Categories
Structural & Seismic
SDC D anchorage, unstable supports, missing member sizes
Accessibility
No accessible routes, 8" thresholds, stairs at all entries
Document Coordination
Floor plan/elevation conflicts, location map errors, generic plans
Code Compliance
HUD pre-emption errors, sprinkler contradictions, concrete strength
Value Delivered
"The seismic anchorage issue alone could have resulted in a dangerous installation. Having an AI catch these fundamental issues before permit submission saved us from both liability and costly redesign."
— Project Team