Zoning is only one of the most obvious of the obstructions to building Missing Middle housing

Zoning is only one of the most obvious of the obstructions to building Missing Middle housing. Parking a close second, especially as it interacts with setbacks, and driveway access to a rear lot, which in turn interacts with fire code, which can require enough space for two cars to pass. 'Stacked duplexes' are popular for a reason--central access alley avoids setback issues and counts as a driveway, so it doesn't trigger fire code issues.