What does the future hold for Albany? One hundred years from now, will Albany look like and the , or will it still be composed of ?
One way to look at the issue is to start with some basic scaling laws and see where they lead us. I’ve built some simple models using a checkerboard, sugar cubes and Elmer’s glue (see the PDF to the right). Although simple, the models yield some very useful insights about the directions Albany could go in the future.
First, let’s take as our standard measure the single sugar cube. It has a volume of one cube, and it has a surface area of six cube faces. Now, take some sugar cubes and make a 2x2x2 double-sized cube (you can look at the attached PDF if you have difficulty visualizing this). Our double-sized cube requires eight single cubes. But here’s the funny thing—each double-sized face only has four single-cube faces.
When you made the cube twice as big, the size of each face went up by two squared (four), while the volume of the cube went up by two cubed (eight). This is a simple illustration of a fundamental scaling law in physics that states when you double the size of an object, its surface area goes up by a factor of four, while its volume goes up by a factor of eight.
But if its surface goes up by four, and its volume by eight, then the ratio of the surface area to volume drops by 4/8 or one-half. So as shapes get bigger, their volume goes up twice as fast as their surface area.
This explains why many science fiction movies are more fiction than science. That giant tarantula that is bigger than a house? In reality, it couldn’t move. Since the strength of its legs is related to its cross section (a surface area), while its weight is related to its volume, the giant tarantula would be too heavy to move.
And if your honey really did shrink the kids, they would die quickly from hypothermia. The surface area of their skin would lose heat so quickly compared to their tiny mass that they couldn’t stay warm.
This scaling law explains lots of other things. Big mammals like elephants have low metabolisms, while tiny mammals like mice have fast metabolisms. Otherwise the elephant would overheat, while the mouse couldn’t stay warm.
Olympic gymnasts tend to be small but muscular. Their small bodies are relatively light compared to the cross-section of their muscles, giving them greater ability to jump. Marathon runners tend to be small and thin. The relatively large surface area of their lungs can keep their muscles fully oxygenated even when they are working hard.
Much of the energy use in buildings is due the need to heat them in winter and cool them in summer. The amount of energy this requires is related to the surface area of the building that is exposed to the elements, compared to the volume of the building. As you probably can guess by now, big buildings have an advantage due to their lower surface area to volume ratio.
I’ve worked out some specific examples in the attached PDF. In each page, there are 64 sugar cube “dwellings” arranged on a checkerboard “city.” The way the sugar cubes are arranged has very different implications for heating and cooling, and sustainability in general.
Let’s look at the first model, which I call “suburbia.” There is one sugar cube per square, for a total exposed surface area of (64 cubes x 6 faces/per cube) of 384 (including the face resting on the ground). That’s a lot of surface area to be transferring heat between indoors and outdoors. This suburbia model will have relatively high heating and cooling costs. Better insulation helps, but you can insulate big buildings, too.
Now let’s add another wrinkle to this model. Assume that a resident of suburbia is willing to walk one square (including diagonally), or is willing to bicycle three squares, but for greater distances they require a car.
For someone living in a corner dwelling, only 1/16 of the city is accessible on foot (including their own dwelling), and only 1/4 is accessible by bicycle. Visiting the other 3/4 of town requires a car.
The next model I call “townhouses.” In this model, there are two-cube duplexes on 32 lots, and half the lots are now empty (more on that later). The number of exposed faces subject to weather is now (32 x 10 faces per duplex) 320 faces. So the heating/cooling requirements are lower, since the number of single-cube exposed faces has fallen from 384 in suburbia to 320 in townhouses.
Notice how much walkabilily has improved. The occupant of a corner house can now walk to 1/8 of the other dwellings, or ride a bike to 1/2 of the city. The proportion of the city that requires a car to visit has fallen from 3/4 in suburbia to 1/2 in townhouses.
The next model in the attached PDF I call “apartments.” The apartments are two-story 2x2x2 eight-plex units, occupying eight squares of our checkerboard city. The number of exposed faces is now (8 buildings x 24 exposed faces) 196. The number of exposed faces has fallen by half compared to suburbia (note that this is exactly the same result as our very first example of doubling the size of the cube). For a corner occupant, half the city’s dwellings are accessible by foot, and all of the city can be reached by bicycle.
The final model I call “towers.” All the city’s dwellings are stacked into two 8-story buildings. The total surface area of the two towers is (2 buildings x 72 exposed faces) 144. The total surface area of the dwellings is only 3/8 of suburbia. All dwelling are within walking distance of each other. Not bad.
I’ll leave it up to the reader to work out the numbers for one more obvious model, the 4x4x4 “big box.” This is not a good model for an apartment building, since many units would not have any natural light, but it’s a good shape for a warehouse or a storage locker building.
Just one more thing. What do you do with all that open space? It’s imperative to keep it green and uncovered by asphalt or concrete. Parks, playing fields, community gardens, whatever. Due to climate change, the estimate is now that 20 percent more water is falling in big rain storms, and the worst is yet to come. Just ask the residents of Manila, Bangkok, Beijing, Duluth, Nashville or New Orleans.
In addition to its recreational benefits, open green space is like a sponge. It can soak up lots of rainwater. Hard surfaces like asphalt and concrete allow the water to runoff quickly and that leads to flooding. Green is good for lots of reasons.
OK, to summarize, there are three very good reasons to allow density to rise: 1) bigger buildings can be heated and cooled more efficiently; 2) density improves walkability and bike rideability, especially in conjunction with public transit corridors: 3) density allows for more and bigger green spaces with benefits for recreation and flood control.
Sounds good, but there must be a catch, right? There is. We want population density to go up in parts of our city, but not population overall. We will have to fight for more density AND more green space in a way that keeps population relatively stable. Higher density can’t become an excuse for letting high-density projects and population growth to get out of hand.
This is a yin/yang vision of Albany’s future. Suburbia is homogeneous. We have to fight for our right to heterogeneity. We have to fight to become both more urban and more rural.
Read more guest columns from Michael Barnes here on Albany Patch.
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