1. Eastgate Centre, Harare, Zimbabwe | Mick Pearce

It uses less energy by 35 percent than a comparable building.
The passive refrigeration mechanism for the building is inspired by the way termites cool their mounds. Cold air is pulled in at night and ventilated during the day as temperatures climb to lower levels.

2. Manitoba Hydro Place, Winnipeg, Canada | Bruce Kuwabara

It uses less energy than a comparable office building at 70 percent.
It has a solar chimney that creates a difference in pressure in a space that allows for cool air to enter space. Other passive systems include winter gardens facing south, and natural daylighting.

3. One Angel Square Manchester, England | 3DReid

This uses less electricity by 50 percent than a comparable building.
It has underground concrete earth tubes to provide the incoming fresh air with free heating and cooling, thereby reducing the energy needed to heat or cool the building.

4. 1 Bligh Office Tower, Sydney, Australia | Ingenhoven Architects

This is the First Office tower in Sydney to receive a qualification ranking of 6 Star/’World Leadership.
It has its own filtration plant in the basement, capable of cleaning up more wastewater currently generated by the house.

5. 30 St Mary Axe, London, England | Foster + Partners

This uses less electricity by 50 percent than a comparable building.
The cooling cycle of the house imitates the filtration process of glass sponges (an underwater organism) through which dust from the base of the building is drawn through. Circulated through various floors, then ejected through the building’s roof.