Why you shouldn’t open your high-rise office windows

It’s a beautiful day outside, and you’re toiling away at your desk inside a freezing cold Manhattan high-rise. The question invariably comes up: “Can’t we just open a window?”

The answer from a couple of experts: Please don’t!

I raised the question at City & State’s Sustainable New York Summit on Thursday, where I moderated a panel called Creative Infrastructure for a Sustainable City. But since I’m just a reporter and not an engineer, the most creative infrastructure I could think of was windows. Luckily, the experts said they’re quite important to energy efficiency.

“A commercial building is designed to ventilate, heat and air condition a space to make people comfortable,” said Nanette Lockwood, global director of policy and advocacy for Ingersoll Rand, a conglomerate that counts the air conditioning manufacturer Trane among its assets. “The minute you change the balance by bringing fresh air into an occupied space without treating it, it automatically throws off that balance.”

Put simply: “If you’re putting unconditioned air in the space, you’re defeating everything that we’re working hard to do!” Lockwood said.

But this isn’t just a public service announcement about why you shouldn’t open your office windows. This is City & State, so there’s a government connection.

New York City is imposing new building regulations starting next year, where all residences, even single-family homes, will have to have ventilation systems.

“You won’t be able to just rely on opening and closing windows for your ventilation air anymore, which is how it’s been done traditionally. And that’s a big change for the market,” said Gina Bocra, chief sustainability officer at the New York City Department of Buildings, who also sat on the panel.

Bocra said that energy efficiency codes have led real estate developers to “tighten” buildings, so less air leaks in and out through walls and windows. “So you really need to bring fresh air in to ventilate the place,” Bocra said. “And now you really need to treat that air.”

Bocra said the new regulations also require the ventilation system to “capture the energy,” using the already warmed or cooled air from the residence to warm or cool the fresh air coming in, instead of exhausting the air directly.

Bocra said mandatory ventilation systems are likely to raise some home prices, but that it pays off through energy savings over time. It’s not a New York City program – national regulations have been adopted by the state – but the Department of Buildings is working through the implications. “It’s getting passed on to us,” Bocra said, “so we’re figuring out how to prepare the industry for that.”