A federally funded apartment complex with ground-floor retail doesn't answer to one accessibility code. It answers to four. The ADA governs the retail spaces and public areas. The Fair Housing Act covers the residential units. IBC Chapter 11 applies through the local building permit. And ICC A117.1 provides the technical standards that IBC references.

These codes don't just coexist. They overlap, and sometimes they conflict. The Fair Housing Act requires 2% of parking spaces in covered multifamily dwellings to be accessible. The ADA has its own parking scoping table based on total lot size. IBC Chapter 11 defers to ICC A117.1 for technical criteria but layers on its own scoping provisions. When a project triggers multiple codes, you can't just pick one and ignore the rest.

The governing principle is straightforward: apply the most restrictive requirement. But identifying which requirement is actually most restrictive for a specific building element takes real analysis. Door width minimums, accessible route requirements, grab bar reinforcement standards, bathroom clearances. Each code addresses these differently, and the "winner" changes depending on the element.

For the ARE, this is pure Objective 2.3 territory. You need to understand which code applies based on building type, occupancy, and funding source. Then you need to determine how those codes interact and which one governs when they disagree. That's the analytical skill NCARB is testing.