Under current federal law, buildings in the District of Columbia can be no taller than 130 feet, save for a short section of Pennsylvania Avenue NW where buildings can reach up to 160 feet.

The National Capital Planning Commission and the DC Office of Planning have been working on a three-phase study of potential economic and aesthetic changes that would result if Congress were to allow slightly-taller buildings in some areas of the district. One part of the study focuses on the economic feasibility of building taller buildings, while another, conducted by DCOP, focuses on visually modeling changes to the D.C. skyline and views from important vantage points from around the region. The models attempt to give D.C. residents and stakeholders an idea of what the district would look like with buildings up to 225 feet tall. While it is encouraging to see discussions about easing height restrictions in DC, the study suffers from both from an unambitious vision, and a structure that largely determined the outcome of the project before any analysis took place.

The visual modeling study does get several things right. First, it correctly assumes that tall buildings will not be built in historic districts, federally owned properties, very low-density areas, historic sites, parks, and other designated open spaces. See the graphic provided by DCOP to the left. NIMBYs sometimes raise the alarm about extremely unlikely outcomes from repealing the Height Act, and it’s important for people to know that the Burj Khalifa isn’t coming to Glover Park for both economic reasons and policy reasons.

Second, the study also provides lots of interesting views (certainly worth clicking through to get a sense of the study), and analysis of areas in which buildings are already up against the maximum height allowed by Congress. After all, the existence of taller buildings is one economic indicator for where actually tall buildings might be built in the absence of height restrictions.

The modeling study also had several serious drawbacks, some of which drastically lower the value of the entire effort.

The NCPC began with three “principles”:.

Principle 1. Ensure the prominence of the federal landmarks and monuments by preserving their views and setting

Principle 2. Maintain the horizontality of the monumental skyline

Principle 3. Minimize negative impacts to nationally significant historic resources, including the L’Enfant Plan

The first principle basically excludes changing much of anything. The second necessarily requires a height restriction low enough to encompass several miles of development. The third is too broad to have much meaning on its own. None were subjected to serious cost-benefit analysis before deciding that they are worthwhile principles to guide future policy in the district. The problematic nature of the principles unfortunately had a direct effect on the quality of the visual modeling efforts.

Much of the Phase 2 presentation focuses on views that, while interesting, don’t help viewers understand what it will be like to live in a city with taller buildings. For example, see this shot from the Air Force Memorial in Virginia:

At first glance, it seems like the monuments and skyline are the central features of the view from the Air Force Memorial. However, this is taken from 500 feet above the actual memorial itself with a very nice camera lens. Unless you rent a helicopter, gain access to heavily restricted airspace, and have excellent vision, you will never actually experience this view.

This photo I took shows the view from the Air Force Memorial as actually experienced by visitors:

At 555 feet tall–more than double the highest building considered in the modeling study–most of the Washington Monument was obscured by small trees until I made an effort to get it into the frame. You might assume that the Capitol dome is also entirely obscured, but because it is such an insignificant part of the skyline from this distance, it is scarcely visible at all. With unlimited building heights it is possible that the Capitol would be obscured entirely, but it’s also important to note that there is not a single building between the Washington Monument and the Air Force Memorial. People visiting the Air Force Memorial wouldn’t have their view ruined by taller buildings, if they noticed them at all.

Similar criticisms could be made of most of the other vantage points included in the visual modeling study. The view from Meridian Hill Park seems to change drastically from a perspective high in the air, but only the tip of the Washington Monument is visible if you actually stand in the park (again, assuming the trees have been recently trimmed). Not much changes when the buildings are raised to max height. Kudos to the authors of the study for including several street-level perspectives, but what they routinely demonstrate is that views of historic sites are largely unaffected by taller buildings.

This raises the rather obvious question of why major building restrictions for the entire District of Columbia are being based, in large part, on views  from perspectives that most of us will only experience in the form of a postcard. Even if allowing taller buildings drastically alters the view from Virginia or parts of the district far away from the National Mall, this potentially negative outcome should be weighed against the rather large costs of current restrictions. Height restrictions cause longer commutes, higher rents, lower real incomes, and less diverse urban areas. How much money should we spend and how many people should we displace so that someone can catch a fleeting glimpse of the Washington Monument from miles away?

If the NCPC is considering changes to our height restrictions, why not model what it would look like if the height limit varied based on distance from the National Mall? For example, buildings could either conform to the Height Act, or build one foot of height for every five feet it is from Constitution Ave. This would preserve the look of the National Mall and areas surrounding national historic sites while still allowing tall buildings in the central business district. That would be a visual model worth building.

NCPC study aside, easing height restrictions in the district is clearly good policy. Doing so is a necessary but insufficient condition for tall buildings. Without serious amendments to D.C. zoning regulations on floor-area ratios, parking minimums, and setback requirements we still wouldn’t have any. Removing height restrictions would simply put control of planning in local hands.

Correction: The Height Master Plan is a joint study being conducted by NCPC and the DC Office of Planning, not by NCPC alone. The post has been updated to reflect this.