Noisy open offices don’t foster collaboration, they kill it, according to a Harvard study that found the less-private floor plan led to a 73 percent drop in face-to-face interaction between employees and a rise in emailing. The problem is plenty of young companies and big corporations have already bought into the open Office fad. But a new startup called ROOM is building a prefabricated, self-assembled solution. It’s the IKEA of office phone booths. The $3,495 ROOM One is a sound-proofed, ventilated, powered booth that can be built in new or existing offices to give employees a place to take a video call or get some uninterrupted time to focus on work. For comparison, ROOM co-founder Morten Meisner-Jensen says, “Most phone booths are $8,000 to $12,000. The cheapest competitor to us is $6,000 — almost twice as much.” Though booths start at $4,500 from TalkBox and $3,995 from Zenbooth, they tack on $1,250 and $1,650 for shipping, while ROOM ships for free. They’re all dividing the market of dividing offices. The idea might seem simple, but the booths could save businesses a ton of money on lost productivity, recruitment and retention if it keeps employees from going crazy amidst sales call cacophony. Less than a year after launch, ROOM has hit a $10 million revenue run rate thanks to 200 clients ranging from startups to Salesforce, Nike, NASA and JP Morgan. That’s attracted a $2 million seed round from Slow Ventures that adds to angel funding from Flexport CEO Ryan Petersen. “I am really excited about it since it is probably the largest revenue-generating company Slow has seen at the time of our initial Seed stage investment,” says partner Kevin Colleran. “It’s not called ROOM because we build rooms,” Meisner-Jensen tells me. “It’s called ROOM because we want to make room for people, make room for privacy and make room for a better work environment.” Phone booths, not sweatboxes You might be asking yourself, enterprising reader, why you couldn’t just go to Home Depot, buy some supplies and build your own in-office phone booth for way less than $3,500. Well, ROOM’s co-founders tried that.…