For our Ideas Issue, we asked guest editors María Arquero de Alarcón and Jen Maigret, “What is one big idea in urban design that hasn’t yet gained traction?” They then began an “idea chain” by posing the question to a colleague, who did the same, and so on. We’re proud to present seven bold visions of the city that have yet to be realized.

Auburn University’s 20K House program construct a durable, sustainable home for $20,000. Now the inimitable university program is asking the question, “What if anyone could do the same?” Our cover story, with new photography from Timothy Hursley, explores this important crossroads in the history of the Rural Studio.

Also Inside: Architerra proves the power of wood, a carbon-neutral University of California, and the world’s first WELL-certified office, plus Jean Nouvel’s One Central Park.