“It's much more for kind of smaller spaces that maybe the landlord has some trouble leasing or wants to focus on other things, and it's been sitting vacant for a long time,” says Rush. “ We've funneled basically all of those spaces into liquid space, so that we can potentially get month to month leases. So, it's not traditional, but you still pick up a way of gaining some revenue on spaces that otherwise would be hard to lease or use a lot of time that would be better spent on other things.”

Brandywine has created an app platform for the liquid space leases that enables potential tenants to look at virtual floor plans of the spaces and agree to terms with a few clicks, Rush says.

Connecting buildings to Internet monitoring yields benefits in terms of reduced tenant complaints and greater efficiency in managing buildings, says Beares.

“Are conference rooms in use? Do the restrooms need to be cleaned, that on-demand cleaning, so that you're not getting complaint calls,” she says. “Do the light bulbs need to be changed? What's the ambient temperature? All of those things are going into the Internet of Things, and driving a lot of change from the back end of office space.”

Larry Steinberg, COO – Retail Group, Rittenhouse Realty Advisors, left, and Jeffrey Tertel, executive managing director, Newmark Knight Frank

Technology is changing the way retail space is being leased as well, says Larry Steinberg, chief operating officer, retail group, Rittenhouse Realty Advisors. He pointed to a three-month lease Dietz & Watson signed for a pop-up store on South Street.

“Retailers now are affected by their Internet sales, but they're also doing brick and mortar sales, and they want to understand what the combination of those two selling methods will yield for them in the way of sales and performance,” Steinberg says. “It's a very difficult row to hoe for them. You have a big shift in the kind of retail that's happening, and the stores that are opening—fashion and soft goods sales—have contracted significantly, but they're being filled up and backfilled by other kinds of retail.”

The changing attitude toward work among younger workers is also having an impact on how developers think about their property portfolios, moderator Tertel pointed out.

“Dad, work is a thing I do, it's not a place I go,” he said, quoting the millennial son of a colleague responding to criticism from his father, whose concept of work was to arrive in the downtown office where he was employed very early in the morning.

“The mobility of the workforce is causing the end user to re-evaluate exactly how much space they lock into a long term traditional lease, versus how much they just use in a flexible hotel sort of structure,” says Brandywine's Rush. “One of the ways we've really adapted to that is leasing out space to a third party coworking facility.”

Enhanced amenities like fitness centers, pools, and large open areas where employees can congregate are also part of efforts to make office environments more friendly and attractive, he says.