Climate benefits of courtyards

Coming from the University of Teheran, architect Mohammad Taleghani is familiar with courtyards. Such enclosed open spaces have been used for thousands of years in different climates. In hot climates, they provide shading. In humid climates, the stack effect enhances ventilation. And in cold climates, they provide protection against the freezing winds. In temperate climates, such as in the Netherlands, the thermal behavior has been studied less. That is, up to now.

Using computer simulations, field measurements and scale model experiments, Taleghani studied the microclimate effect of courtyards in summer and winter.

In the summer, courtyards provide the highest number of comfortable hours. And although they’re not very commonplace in temperate climates, climate change and the urban heat effect might change that in new or renewed urban settings, said Taleghani.

Measurements have shown that vegetation in a courtyard can reduce the temperature by more than 4 degrees Celsius. Water pools keep down the temperature as well, with the added benefit that they re-radiate the heat during the evening and night.

That way, courtyards reduce the energy need for cooling in summer. In the winter, the temperature in the courtyard is also about 1 degree lower than in the open environment. But that effect is compensated by shielding off the chilling winds.

Taleghani concluded that courtyards of approximately ten by ten metres, filled with green vegetation and water surfaces, provide comfortable places in summer (May – August), reduce energy need and counteract the urban heat effect. Which, in the context global warming, might offer a welcome way of mitigating urban climate change.

Mohammad Taleghani, Dwelling on Courtyards, Exploring the energy efficiency and comfort potential of courtyards for dwellings in the Netherlands, December 3 ,2014, PhD supervisor Prof. Andy van den Dobbelsteen (Faculty of Architecture and the Built Environment).