DC skyline. CC image from James Calder

Continuing on the discussion of DC’s height limit (and potential changes to it), I wanted to take note of a few more articles on the subject.  George Mason law professor David Schleicher (he of land-use law and procedure fame) asks height limit proponents six basic questions, all of which more or less ask proponents to weigh the trade-offs – or explain why they think the trade-offs do not exist. The six questions:

1. Do you believe supply is important in determining prices in housing and office markets?
2. Why do you think development should be spread out?
3. What effect do you think limiting heights has on agglomeration, including the depth of local markets and information spillovers?
4. Why do you think D.C. will grow without going up?
5. Do you think D.C. would instantly become as tall as New York upon repeal?
6. How much is the D.C. aesthetic worth?

All good questions. So much of planning work is about discussing these trade-offs; an honest discussion of the costs is a prerequisite.

One comment on numbers 5 and 6: DC can indeed go taller while still maintaining the aesthetic of a ‘flat’ skyline, if that is something of value to residents (and therefore worth the cost).  The height limit’s maximum and the flat nature of DC’s skyline are two separate things; if DC’s height limit were set at 200′, we could expect buildings to eventually fill that envelope with numerous buildings up against that limit, rather than form the wedding cake shape of many other American skylines.

Indeed, if that flat-ness is what we value, then we shouldn’t fear adjusting the heights upward – opportunities to shape the city will still exist.

I also wanted to highlight a comment in Kaid Benfield’s original Atlantic Cities piece from ArtR:

1) at current demand for jobs and housing DC has at least a 30 year supply of land to add over 200,000 more jobs and 169,000 people without changes to zoning or the height limit (DC Office of Planning).

I don’t doubt that this is true, but the question of how much land is available gets back to the old real estate cliche of location, location, location.

2) Density through high rise steel and concrete construction will not increase housing affordability. Hard costs alone are over $200/sf with soft cost, land and profit you are well over $400/sf and with even minimal parking you are over $500/sf, thats $500,000 for a small two bedroom. To the extent high-rises syphon off high-income households that might stabilize less costly forms of housing but I am skeptical.

Art is making two points: one about costs, and one about filtering within the market.  In terms of costs, Art is absolutely right – relaxing the height limit will not magically lower construction costs. However, couple that reform with others (such as the aforementioned reduction in required off-street parking) as well as efforts to speed approvals and reduce the lead time required for building and we’re on to something (all potentially positive outcomes of DC’s zoning code review).

The point about filtering is trickier.  Certainly, in the abstract, adding more supply should relieve pressure on older housing units to filter up to more expensive submarkets, but the key phrase in all such abstractions is “all else being equal.”  All else is clearly not equal, and I can’t blame someone for skepticism on the ability for upzoning to make this happen – particularly when such changes to the zoning code happen on an ad-hoc, case-by-case basis.

3) There is a difference between capacity and supply. Raising the height limit may increase capacity but it does nothing for supply. Supply is a function of developers meeting demand and development stops the instant prices stop rising.

While this point is also true, the nature of the equilibrium depends on the other factors influencing cost.  For example, take the examples from Portland, where the elimination of on-site parking requirements allows some development to pencil out a lower price point.

There’s also a point to be made here about location.  If our goal is to add supply, the market might be able to support a lot more supply in more desirable locations.  However, if most of the District’s developable capacity (in point 1 above) is not in those locations, then it will take something else to turn that capacity into new supply.

4) There is nothing to suggest that height alone will increase demand. In fact, too much capacity can increase uncertainty because you never sure how much your competitor can absorb. Denver learned this when they down zoned neighborhoods and they took off.

I hope no one takes away the idea that changing the height limit alone will lead to some magical change in DC’s built environment. Given the fact that zoning is usually an even greater constraint (and given the procedural challenges it can impose), it shouldn’t be seen as a panacea.