Population growth is causing cities around the world to expand to accommodate more people. The downside is that as locations become more urbanised they also heat up. This can cause a number of problems. To tackle the issue architects need to be more careful with their designs as well as the space between buildings. Whether it is residential, public, or commercial architecture, the properties should benefit the area.

What is the cause?

The main reason big cities are so much hotter than the suburbs and countryside is the abundance of certain building materials. There is likely to be much more concrete, tarmac, and glass in a city. The first two can absorb heat very efficiently and hold it for a long time. Glass can effectively redirect and focus sunlight, providing further heating.

In studies it has been noted that cities with a tight grid layout tend to be hotter than those with a more informal footprint. The tighter buildings are together the more heat they can absorb. In some cases the spaces between buildings trap a huge amount of heat. This is why grids tend to produce the highest temperatures. Informal layouts create more space, allowing more cooling to take place.

An abundance of skyscrapers can also make a city much hotter. The taller buildings are, the more heat they absorb from each other, especially if they are close together. You may think dark areas between properties will be cool because there is little sunlight. They can actually be very warm because the heat is trapped and takes a long time to dissipate.

What is the solution?

Architects are working hard to find solutions. One option is to ensure areas between buildings are designed carefully to allow cooling. Using less concrete, tarmac, and other materials that absorb lots of heat can help too. There are alternatives that are reflective instead.

A great option is to introduce more greenery to a city. Plants, trees and flowers have a naturally cooling effect. Sadly many cities got rid of most of their vegetation. New buildings could include more, particularly in the form of green roofs. They can be very cooling.

Commercial architecture, public buildings, high rise residential blocks, and even individual homes all have a part to play. With good designs cities may become cooler and more pleasant places to live.