Where zoning and building codes overlap
For those into a very technical discussion about building height, height restrictions and construction realities, Payton Chung has a long post that details the issues relative to Washington, DC. He writes:
The 1899 Height Act set a construction limit of 90 feet in much of DC, effectively 7 or 8 stories. This height poses a particularly vexing cost conundrum for developers seeking to build workforce housing in DC's neighborhoods. It's just beyond one of the key cost thresholds in development, between buildings supported with light frames versus heavy frames.
Fire safety codes require that buildings over 6 stories have heavy frames, but rents in most of the city don't quite justify the considerable added cost. Instead, valuable land near downtown sits empty, outlying areas that could support taller buildings instead get low-rise buildings, and the city gets fewer new housing units. New construction techniques could offer a way out.
If it weren't for the Height Act, developers wouldn't just sit and wait on sites like these. They'd probably just build Type III buildings, and if there's still demand, they could build Type I downtown towers with 20+ floors. But due to the Height Act, DC is one of the only cities in America where there's a substantial market for 7-8 story buildings.
To break this logjam without changing the Height Act, DC's building community can embrace new light-frame construction techniques that can cost-effectively build mid-rise buildings without the need for steel beams and reinforced concrete. Local architects, developers, and public officials could convene a working group to bring some of these innovations to market, and thus safely deliver more housing at less cost.
And of course there's always the discussion about changing the Height Act itself (which I, for one, think should be done with extreme caution). The whole post is worth a read if you want to understand some of the technicalities of construction and how they impact development and building height.
Since creating mid-rise, affordable buildings are important to the future of quality city living, I hope Howard Blackson weighs in to the discussion. He wrote previously in a piece about rejecting towers as a solution for urbanity and embracing mid-rise:
In focusing on getting the street right, we’ve lost sight of the 3-dimensional ramifications of building 6-story, 85-foot tall, Type III construction buildings on 10 – 15,000 sq. ft. lots with large, expensive, tightly stacked units. The maximization of profit potential within our legal building envelopes is causing the latest neighbor-to-neighbor conflicts over proper light, air and the need for private space within the block itself.
The interior of the block is not throw-away space. It’s another vital realm where urbanism occurs and, traditionally, has contained spaces where people live, play, work and relax. While we may never achieve a New Orleans’ mid-block courtyard pattern, our regulations should foster a greater diversity of building types — not just towers and full-block buildings, but also the more organic perimeter or liner block buildings with courts and stepbacks interior to the block.