SAN FRANCISCO — From the outside it’s just a beige three-story building in a quiet residential neighborhood. But inside, in a third-floor apartment, there are enough Ikea bunk beds to sleep 10 people, crammed into two bedrooms. The living room is bare except for a futon, a tiny desk and laptop power cables strewed across the hardwood floor like a nest of snakes.

The tenants, mostly men in their 20s, sleep next to heaps of dirty laundry. There is no television set; the men watch online video, on laptops with headphones. On a recent afternoon, 23-year-old Steve El-Hage, who came here from Toronto in May, ate slices of ham straight out of the package: “As you can see, I was going to make a sandwich, but I didn’t get there.”

This is not some kind of dorm, but a “hacker hostel.” It’s one of several in the Bay Area that offer short- or long-term stays for aspiring tech entrepreneurs on the bottom rung of the Silicon Valley ladder, those who haven’t yet achieved Facebook-level riches. These establishments put a twist on the long tradition of communal housing for tech types by turning it into a commercial enterprise.

The San Francisco hostel is part of a minichain of three bunk-bed-stuffed residences under the same management, all places where young programmers, designers and scientists can work, eat and sleep.