+ 45

+ 7

+ 9

+ 17

+ 23

+ 18

+ 11

+ 19

+ 43

+ 14

+ 15

If there's one word that sums up our most popular projects of 2015, it's "diversity." The list features architects ranging from old favorites such as SANAA, Diller Scofidio + Renfro and OMA down to newer names like Sculp[IT] and Tropical Space; it also includes everything from museums to multi-family housing and spa retreats to chapels - along with the usual smattering of private residences. Interestingly, this year's list also shows the symbiosis between great architecture and great photography, with no less than 4 projects also appearing in our most bookmarked images from this year's World Photo Day. But despite their diversity, there's one thing all of these 20 projects have in common: great architecture. So settle in, relax and read on - here's our 20 most popular projects of 2015.

+ 23

+ 13

+ 9

+ 9

Created by the Union International des Architects (UIA) in 2005, World Architecture Day is celebrated on the first Monday of October with the aim of reminding the world about the collective responsibility of architects in designing our future cities and settlements.

This year, the UIA has selected “Architecture, Building, Climate” as the theme of the day, seeking to highlight the essential role that architecture, design and urbanism have in the reduction of greenhouse gas emissions. With international climate treaty negotiations set to happen later this year, the “UIA members, working bodies and partners will mobilize on 5 October to promote actions and solutions that apply the enormous power of architecture and urban design in coping with global climate change, one of the greatest challenges of our time.”

Through small actions architects can collectively make a big difference and create significant changes. To celebrate World Architecture Day, we have rounded up a selection of projects that have taken steps towards the challenge of protecting our environment.

+ 15