The skyscraper was the twentieth-century symbol of power and success, forming the highrise jungle of successful cities like New York, and copied in Hong Kong, Sao Paulo, Dubai, Kuala Lumpur, Beijing, and a long list of cities arriving into the fast growing global club of movers and shakers.
Most modern skyscrapers are of the steel-and-glass construction pioneered by the architect Mies van der Rohe. Here's one example: the building that houses the Department of Electronic Engineering, Mathematics and Computer Sciences at the University of Delft.
Its still a handsome building to look at. But its windows, facing east and west, catch the sun very efficiently and turn the place into a giant greenhouse. A very long time ago, as a physics freshman, I used to take an introductory electronics lab on some high floor on afternoons, but nobody ever enjoyed the view as the teaching assistants always kept the shades down and closed as tightly as possible. Even so, I sweated over those labs, and not just because I wasn't all that good at electronics.
As it was a fall course I never did find out how the building did in winter, but since it was constructed before double-pane windows were a thing, my guess is it could get pretty cold on the side that was not in the sun, which was at least half the place.
What I'm getting at is that climate control in this type of building is an energetic nightmare, even in the kind of temperate climate Mies van der Rohe hailed from. I shudder to think of the carbon footprint required to keep highrise livable in places that get cold, like Toronto, or that get super hot, like Dubai.
Yet here is New York, a place that gets both cold winters and hot summers, whose climate action plan calls for its buildings to cut their carbon footprint by 40 percent by 2030, which is only a decade away. On the other side of the continent, Vancouver's glass towers are said to undercut the cities nice climate action plan.
What to do?
One immediate way the occupants can make a difference, is by lining their windows with aluminium foil. You scoff. But I did this for my aunt who suffered through that blistering heatwave in the Netherlands in 2018, and whose kitchen was a blaze of heat in the afternoons. I taped up its window with aluminum foil. This made it look terrible, and she had lost the view. But it cooled down the place considerably, so she left it on until the heatwave passed. (Note 1. This is not recommended for double glazed windows, which can be damaged by the heat buildup. Note 2. Light coloured curtains or blinds do a similar job, less effectively but a lot prettier).
For new buildings, architects have a wealth of local knowledge to tap into, in what is called "vernacular" architecture. Examples are adobe homes in the American southwest, or raised bamboo homes in southeast Asia, or stone homes in Scotland, each optimised for its local climate and using local building materials.
One spectacular recent example is the Al Bahr towers in Abu Dhabi: a pair of steel-and-glass buildings of which the energy required for cooling is cut drastically by the addition of an external screen. The screen is a modern version of the traditional screen ubiquitous in the Middle East, with an inventive Japanese twist that allows each panel to be folded, origami-style, to reveal the view when the sun is not beating on that side of the building.
Another example is the Hotel Jakarta in Amsterdam, which looks on the outside like any other glass-fronted highrise but is packed with features that work together to make it low emissions in its operation. It has a wood-frame modular construction, skipping the use of high-emissions concrete.
There is - of course - PV on the roof. The lush tropical garden in the atrium is sustained by a gray-water system and sprinkled by rainwater. Much of the trim is done in sustainably harvested bamboo. The windows of the rooms are double glazed, and in winter a set of sliding glass panels can be closed over the balconies, turning these into an extra layer of insulation. Rooms are kept warm / cool by the floors, fed by a central heat pump. Oh, and the design is beautiful inside and out.
This is where all highrise buildings need to go in our low carbon future: low-carbon, innovative, and diverse. Far from being dark, cold or ugly, buildings like these demonstrate that a low-carbon life can be very attractive indeed.
As for that building at the University of Delft: The university has decided to take it down. But the building is an iconic landmark, and one current proposal is to ask a university group to redesign it to become an energy-neutral student dormitory with possibly public spaces (think meeting space on the top floors, and a cinema in the erstwhile lecture rooms). Delft student groups do really well in energy efficient building contests like the Solar Decathlon: why not apply such know-how to their campus buildings?
In general, I think it's an exciting time for innovative architecture. I really look forward to seeing out of the steel-and-glass box designs that are more interesting, better for the planet, and a pleasure to live and work in.