Next month, Portland will whittle the proposals for the Broadway Corridor site, aka the USPS site at the edge of the Pearl and Old Town, down to a shortlist of designs. The 32-acre site anchored by the city's aging central postal facility sits just west of Union Station and south of the Broadway Bridge—a prime piece of real estate.

So far, William Kaven Architecture's ambitious proposal has made the biggest splash—even if, on paper, it seems the least likely to actually get built. With two giant high-rises—both exceeding 900 feet, and connected by a 236-foot-long skybridge—as the showpiece, WKA is proposing 5 million square feet of new residential, retail, and office space, including an extension of the North Park blocks, reflecting pool, museum, four new residential buildings, and indoor market.

We asked Daniel Kaven, one of WKA's two founding brothers, to fill us in on his firm's ambitions. Here are three things he told us.

1. The proposal makes room for a future high-speed transportation hub.

“The idea behind this is to future-proof some underground transportation. This would actually be the entry to a high-speed transit system below Broadway. Here’s the main thing: this is a massive undertaking, and it’s a huge piece of property in the center of our city. We’re doing an injustice to our citizens if we’re not planning how to deal with growing by exponential numbers in the next 20, 30, 40 years. We have to think about: how does Portland integrate into high-speed transit all along the West Coast? And there’s a lot of new tunneling technology and a lot of new rail technology. And that’s a good place for it. You have Greyhound, Amtrak, MAX, streetcar. It’s all right around there.” 

2. The plan would demolish the sloping approach to the Broadway Bridge on NW Broadway.

“We’re proposing removing that ramp and only having that ramp down on Lovejoy. By doing that, you really merge Union Station to the Pearl District and the Pearl District to Old Town and Chinatown. I mentioned this in the press release, but no one has really caught that. In my mind, it’s one of the biggest ideas that we have. If you go and stand there, you can look at it and think to yourself, why is this here at all? It’s like an albatross lying around. The streetcar goes up and down Lovejoy, and there’s absolutely no need to have two down ramps from the bridge. If we got rid of the second ramp down, then you don’t need a light that we have right now. Additionally, you’d have all these streets that would go from Union Station across the new development. The postal block right now is blocking two or three major thoroughfares and those would then be linked all the way across.”

3. The skybridge will be big enough to have trees growing in it.

“The big idea here is [to make it] a destination, if you can imagine like a botanical park in Brooklyn or someplace like that—they have a really nice one. It’s a 50-foot high space. So in the rendering it looks like a story or two, but it’s 50 feet high. There would be elevated planters and things to grow trees and lots of plants. The idea is to have an indoor respite from the gray weather, and it’s a destination. People in Portland or from out of town would be able to come and go up to this botanical garden and be able to sit and hang out and see the mountains and the skyline. It’s essentially a very real-sized bridge between the buildings with massive trusses on either side.”