The Architecture of Remembering

There are some foolish buildings in Chicago. There are buildings that are separated from their neighbors by only a few inches.

Buildings like these:

Or these:

In another city, I was at a bar that had one of these small gaps between it and its neighbors. I was asking the bartender about this little gap, and he matter-of-factly replied, “Oh, sure, you’re talking about piss alley.”

Piss alley. It’s a bit crude, but all in all, an apt name. This bar’s piss alley earned its moniker due to it being a discrete place for men to relieve themselves after a night of drinking, but really, if you know anything about energy efficiency, it seems like an appropriate name for any little gap between buildings. Instead of two buildings wisely sharing a wall in which no heat is lost between the attached walls, there is just a useless gap between them, good for nothing except for perhaps taking a piss in it. Rain falls between the two buildings in the gap. Debris and trash piles up. Cold winds flow freely between the buildings in the winter, sucking heat away from both walls.

In the time when heating was expensive and difficult, buildings in climates with cold winters like Chicago commonly shared walls between them. It is old architectural wisdom, and there is good reason why many old cities in cold climates have buildings with adjoining walls.

Easy access to fossil fuels has allowed us to forget this old wisdom. We are able to design our buildings carelessly and then let central heating and air conditioning do the rest for us.

I once heard a description of modern buildings as patients hooked up to an I.V., relying on a steady supply of fossil fuel inputs to survive. Without the fossil fuels, many of our homes would not be livable. 

But it doesn’t need to be this way.

There are other options.

The climate writer, Jeff Goodell, used the phrase technology of forgetting to describe our reliance on air conditioning to keep our buildings cool. Mr. Goodell visited an 18^th-century building in India that was able to stay comfortable on a hot day solely through passive means. The building had thick walls, an indoor foundation, and a ventilation system that channeled wind through each room.

These passive techniques are still available to us, but they are unfortunately uncommon. Indeed, our modern technologies have led us to forget the wisdom of our forebears that allowed us to live in severe climates before the age of fossil fuels.

In the age of climate change, we no longer have the luxury of being foolish with how we design and construct our buildings. To counter these technologies of forgetting, we need an architecture of remembering to keep our homes comfortable without relying on fossil fuels.

I used to live in Chicago and would take many walks through my neighborhood. On these walks, when I would pass buildings with small gaps between them, I wondered if there was a way these buildings could be retrofitted to correct the thermal inefficiency of two buildings being separated from one another by only a few inches.

Years later, I decided to conduct some research. I found two uninsulated brick buildings in the city. Picture a couple of classic brick buildings, two-stories high. The buildings are almost row homes, but not quite, as the buildings have a six-inch gap between them.

I didn’t exactly connect these buildings together. I simply stuffed batts of mineral wool insulation around the edge of the gap and then covered this insulation with metal flashing. Structurally, the buildings maintained their independence, but thermally, the buildings effectively now shared a wall.

My first instinct is to invoke a parasite to describe these buildings glomming onto each other, but that’s not quite right. These buildings have joined together through a mutual symbiosis. Both buildings benefit. It is an architecture not only of remembering, but of mutual dependence and cooperation as well. It is an architecture of sharing.

I worked with some smart building scientists at the Illinois Institute of Technology who studied the wall before and after this retrofit. The findings? The heat flux through the wall was reduced by 70% after the insulation was in place. Each year, this newly formed party wall would save 1.9 metric tons of carbon dioxide a year. (A typical car emits 4.6 metric tons a year.) If we are concerned with money, the savings on heating costs that both buildings would see was estimated to recoup the costs of the project in four and a half years.

Of course, these buildings will still use fossil fuels. Even wisely designed buildings will require heating and cooling inputs in most climates. Passive solar design and shared party walls can only go so far. Luckily, our modern technology is getting better at keeping our buildings comfortable while using less fossil fuels. We have heat pumps, solar panels, and effective insulating materials available to us now. These will be important tools to employ as we wean our buildings off of fossil fuels, but I think we would be making a mistake if we solely looked to new technology to reduce our building’s carbon emissions.

The new technology is still something you have to buy. A grid-connected heat pump is still subject to the vulnerabilities of power outages. New high-performance building insulations are often man-made, carbon-intensive products to manufacture. Solar panels require intensive mining. We should absolutely use these new technologies because they are significant improvements over our current fossil-fuel-dependent furnaces and central air conditioning units, but we should use them appropriately and minimally. They are not silver bullets. A wise course for the future of building would be a marriage of the new and the old, to design our buildings deploying passive heating and cooling techniques first. And only then, after thoughtfully designing and constructing our buildings, should we look to the new technology to finish the job of keeping our buildings comfortable.

Nobody is selling the architectural wisdom from the past. Perhaps that is why I hear more about heat pumps instead of party walls in discussions about energy efficiency, but even if it is not for sale, the passive techniques are still there. We just need to remember them.