Whether it's designing efficient skyscrapers, creating whole cities which aim to be carbon neutral or re-building out of the rubble created by natural disasters, architects are changing the way we experience the built environment, finding solutions to the ecological challenges -- big and small -- of the 21st century.

The new Model T?

The McLaren F1 designer, Gordon Murray is creating a green, affordable city car.

A clean set of wheels

Is the petrol engine about to be overtaken by a new fleet of hydrogen fuel cell and electric cars?

Camping up in the trees

Dangling from a tree like a surreal oversized pear, the Treetent is a cross between a treehouse and a tent.

    Virtuous cycles

    New technology is turning sessions in the gym into clean renewable electricity.

      Boosting solar efficiency 

      Researchers have developed a new anti-reflective nano coating that could increase the take up of solar power.

        Singapore: Debate highlights

        What is 'Design for Good' and are we doing enough of it? Our PVs debated the issue in Singapore.

        Turning CO2 into fuel

        It's not the most obvious candidate for recycling. But reusing CO2 could see benefits for the economy and the planet.

        Quick Vote
        What type of vehicle will be dominant by the end of the 21st century?
        Principal Voices on CNNI
        Principal Voices on CNNI

        CNN's Charles Hodson presented the second Principal Voices program: "Principal Voices: Design for Good" which aired in late August. Watch it here:

        Part 1: Designing for good Video
        Part 2: Open architecture network Video
        Part 3: Turning urban China green Video

        Daniel Libeskind

        His buildings are some of the most recognizable and radical designs of the early 21st century.

        Cameron Sinclair

        Bringing design to some of the world's most impoverished and disaster-hit communities.

        Peter Head

        The award-winning architect is playing a leading role in the plans to build China's first eco-cities.