There are two important ballot measures in Cupertino this fall prompted by The Hills at Vallco plan to build a new downtown on the site of the dead Vallco Mall.

We recommend yes on Measure D to move forward with the imaginative Hills plan.

As to Measure C — no way. Conceived as a way to prevent the Hills from being built, it morphed into a nightmare: the classic ill-drafted citizen measure rife with unintended consequences.

Measure C wouldn’t only stop the Hills plan. It would prevent just about any redevelopment of Vallco, which today is a world-class eyesore. And, by the way, Measure C would raise the building height limit in city neighborhoods to 45 feet. That’s’ right, four stories.

It would be a disaster for Cupertino. Vote no.

Measure D is a yes or no vote on the Hills at Vallco plan for the 58-acre mall site. If you don’t like the plan, Measure D is where to express that view. But we hope voters say yes to it.

The fanciful, futuristic downtown design combines stores and entertainment — the AMC movies would stay — with homes, offices and acres of indoor and outdoor community space. Its signature feature is a 30-acre public park on what would be the world’s largest green roof — a capstone of architect Rafael Viñoly’s stellar career.

Apple, Google and Facebook are moving to signature designs for their campuses, but imaginative architecture in the public realm has yet to take hold in Silicon Valley. Cupertino — home of Apple’s spaceship — can set the pace.

Ironically, the very ambition of this plan puts off some residents, who worry that Sand Hill’s abortive bid to redevelop Sunnyvale’s downtown on the brink of the Great Recession could be repeated.

This time, however, Sand Hill’s financial partner seems to be in it for the long haul — and Measure D leaves no wiggle room on community benefits, including tens of millions of dollars for schools and highway improvements. The rooftop park will cost in the hundreds of millions.

The Hills at Vallco won’t make a dent in the valley’s housing shortage. Sand Hill at least should max out the range in the plan to 800 apartments, including some affordable senior housing. But the low numbers aren’t the developer’s fault. They’re in compliance with Cupertino’s general plan.

Ballot box zoning of any kind is rarely a good idea. But faced with the loopy proposal that became Measure C, Sand Hill was right to put its plan on the ballot on the ballot as well. Yes, as opponents say, the developers will profit from this. They’d better; there is no public money in it. But Cupertino residents will benefit enormously, too.

Vote yes on Measure D. And no, for sure, on Measure C.