Wednesday, August 7, 2013

Questions of Climate and How Transpo Networks Impact Building/City Form

I very much enjoy giving presentations, particularly about A New Dallas, highway tear-outs, and the true essence and impact of congestion and mobility. Anybody that's ever had drinks with me can probably attest that if I wasn't in front of an audience, I'd create an audience where I'm at and go off on (more colorful) diatribes anyway.

I love talking cities. What I love even more is getting new questions that I haven't already prepared myself to answer. They always help me reevaluate my message and strengthen the overall argument. Two recent discussions/forums I have received a similar question. And that is, "what financial incentive do you have for all this work?" The answer is zero. If anything, it's the hope that there will be plenty of design work for all of the local firms to contribute to an improved Dallas over time.

Another question that came up at the Greater Dallas Planning Council Board of Directors meeting was the issue of climate. This is one that I've thought of and combated quite a bit within a different context, that being whether Dallas was too hot for walking and biking, but never in direct regards to the 345 tear-out plan. So I wanted to take a few minutes to flesh out that answer.

1 - DALLAS HAS BETTER WEATHER THAN WALKABLE CITIES It's why I live here. I suspect there is a bit of a bias at work because the few summer months can be so extreme that it's all we think about, particularly whilst in the midst, and it's all we're known for nationally. Which is pretty sad when you think about it. 

The first part of the answer echoes the broader question of a hot climate on walkability/bikeability. This is dumb. In fact, I thought we had gotten over the belly-aching that it's too hot to walk or bike in Dallas. I'll explain more in a bit, but here is where I remind that Dallas has three hot months, 6 Chamber of Commerce months where the sky is blue, the sun is out, the air is clear, the grass and trees are green, and the thermometer is pinned to 70. Sounds like lousy biking/walking weather to me. Better barricade ourselves in the car.

And then there are three winter months where the weather is so so, otherwise known as an average Summer day in Copenhagen. The best cities for walking and biking have pretty lousy weather. They almost have to be in order to differentiate themselves within the competition of cities. Dallas has 9 good to great months for walking/biking (whether recreational or as [/serious voice] SERIOUS TRANSPORTATION), Copenhagen and Vancouver have like one, August.

Imagine if nice weather cities ever get their act together. Perhaps it would be a better idea to build a better city and then go on holiday in August to Copenhagen or Vancouver for the entire month like the Romans do (to the beach) to get out of sweltering Rome in August (which is kind of ironic when you consider the etymology).

2 - DALLAS IS NOT BUILT FOR ITS CLIMATE This is really the point that will underscore most of the rest of this post, outlining how Dallas could/should be designed for its climate, particularly, the heat. Implicit within the question of whether 345 tear-out and its tenets of improved walkability and compact city form is the assumption that Dallas, as it currently exists today, was in fact built for its climate. We can go from our air conditioned home, to our air conditioned garage, to our air conditioned car, which gets increasingly comfortable the more time we're forced to spend in it, to our air conditioned job (if we're so lucky), to air conditioned tunnels (!) downtown to get lunch and back. We never have to breathe unconditioned air! Ain't it swell?!

This assumption is incorrect. I suspect one fueled out of reflexive intellectual laziness that believes the world we occupy is and was inevitable. That there wasn't a long string of processes and dynamics at work and the interplay between them evolved our current environ. In reality, Dallas was rolled off an assembly line of copy and paste land use codes, transportation standards, and economic modeling. That is, the Dallas that exists today, just like every other Sun Belt city in Generica. Not, the Dallas that existed pre-air condition

Air conditioning is just a technology. And one that is ubiquitous. It works in any environment. They even have it in Copenhagen! Amazing, right? That a third world nation (they are right, because they're not us) with better standard of living, better education, better healthcare, better democracy, and better capitalism, yes capitalism would have the hottest technology in the Southwest.

 Like heat, all it does is regulate extremes. Which can be done in better, more efficient and cost effective "pre-design," low-tech ways through urban form and passive heating/cooling strategies. By relying on the "gadget green," which AC was the first form of, it's very high energy and allowed us to be dumb with how we design our city, particularly as temperatures rise, energy prices rise, and we're faced with prospect of more rolling brown-outs.

In recent presentations I've been showing the comparison of Madrid metro area to DFW metro area in terms of city size. I like the comparison to Madrid because they are roughly the same size (about 6.5 million) and have pretty close to similar climates, just bump average temps up 5 degrees each month from Madrid and you have Dallas, mostly because Texas isn't surrounded by water like Spain is. It shows Madrid, again same population, almost entirely fitting within 635. It takes about 1/20th of the land area that comprises all of DFW.

Furthermore, I compare this to Madrid city form based on Dallas densities of 1950, which is still only 1/14th of the land area that it currently occupies. More compact city form means more areas of preserved natural areas which are like heat sinks, absorbing carbon dioxide, off-gassing clean oxygen, and absorbing the sun's energy to catalyze the process.

3 - A MORE COMPACT CITY REFLECTS MORE HEAT BACK UPWARDS Aside from transportation technology, this is why Seville (climate even closer to Dallas than Madrid) or the historic parts of Dubai are incredibly compact with very tight streets. When there is a greater portion of roof surface area than ground surface area for the sun to shine on, less heat actually gets down to where people are. This is why Steven Chu suggested painting roof tops white to reflect heat upwards and away from cities to reduce urban heat island effect.

To help explain this, I'll use a figure ground of Detroit pre-car and post-car:

Shown in black are outlines of buildings, roof lines if you will. White is anything not buildings, basically the public realm. As urban form began to erode over time in order to make way for bigger roads and more surface parking lots, that opened up the public realm for more heat gain. Dallas has a similarly dispersed footprint, where there is far too much pavement absorbing and amplifying heat.

While Chu recommended reflecting heat, we're probably not too far away from Photovoltaic technology advancing to the point of price competitiveness where rather than paint roofs white, we're affixing PV to the roofs and powering our buildings (to some degree) beneath. Rather than reflect it, we're using it very close to the source, reducing transmission loss. Germany buys energy from local providers via wind and solar at an inflated price to encourage cleaner, more ubiquitous energy and it has sparked an entire new industry of bottom up investment and energy production.

4 - A MORE COMPACT CITY BETTER REGULATES TEMPERATURES Based on the previous point, you could say dispersed buildings is good for Dallas and bad for Detroit. But it works both ways. In cold climates, you want buildings closer together to preserve heat, reduce heat loss, and minimize cold winter winds cutting through the city. Think of penguins huddling close together during a blizzard.

On the other hand, I like to point out an anecdote about my office space, which is on an incredibly pleasant woonerf-style, curbless street in uptown. It is tree-lined and it unites two mid-rise mixed-use residential buildings. I can see the sun out on the street, but for the most part the entire street and our office is shaded at all times. Our daily peak energy usage is 3x higher in winter than in summer and we only have to run the AC occasionally and only during the hottest days.

 All of this is why transportation is so important. It dictates the real estate market. It is the invisible arm to real estate and land use's invisible hand. However, arms are responsive to brains and that is our public policy comes in. This is why it is critical to have the debate about transportation "improvements" and improvements in public and at a political level. Not merely accepting what TxDOT says. Because they clearly don't understand how cities work nor have their best interest in mind.