The first step is learning whether your building will be at risk for not meeting the 2024 targets. The Bloomberg administration required New York's largest buildings to conduct energy audits and retrofit systems to increase efficiency. Buildings larger than 50,000 square feet were required to undergo audits every decade.

Unger describes energy efficiency audits as “taking a full holistic view of the building and all of the things that require energy consumption, determining where the owner/operator should focus efforts to reduce energy consumption.”

Efficiency engineering firms or consultants often bring in Sentient whose wireless technology can measure how systems are functioning. Assessments can cover HVAC systems, the boiler, the chiller plant, air handlers for cooling and heating, and the lighting.

Second, based on data from the audit, property owners should identify the most critical problems. These are areas which will cause a portfolio of buildings to miss the 2024 target. “You only have five years to meet the first set of targets, so you're going to have to look at a five-year horizon of when you're going to make specific investments that will ensure your compliance by that date,” Unger says.

He describes fixes to air conditioning and heating in buildings that lack proper insulation. Steam systems need to be balanced. “It's just making sure that everyone gets an even amount of heat, so you don't get very cold apartments and very hot apartments because that's how a lot of energy get wasted.” A change to LED lighting can drastically reduce energy consumption.

Third, the building owners will need to create a long-term capital budget plan to meet the requirements for the 2030 target and beyond. Unger is observing a transformation in how energy is moving beyond fossil fuels to “distributed energy resources.” Instead of a central power plant providing energy from oil, coal or natural gas, the sector is looking at distribution through networks of solar panels, hydro-electric power and wind power networked in grids at a micro-level.

“There are many ways that you can generate electricity at a building site that can be shared with the rest of the grid, and that's where I think the future is going for buildings,” says Unger. Although he does not anticipate this system up and running in the next 10 years, it's another development that could help buildings reach the 2050 target.

How do the modern steel and glass towers fit in this push for environmental protection? Developers at both the World Trade Center and Hudson Yards have proclaimed their new buildings are at the forefront of sustainability. Hudson Yards markets itself as “the largest LEED certified neighborhood in New York City.” Yet Mayor de Blasio has pointed out the massive glass towers are major contributors to global warming.

Unger explains state-of-the-art technologies can be used for heating and cooling in glass towers. “But no matter what you are not going to get the same insulation with glass that you are with concrete and brick. If you opted not to use glass as your building material, you could perhaps reach even higher efficiency standards,” he says. “But with old pre-war buildings you have inefficient heating and cooling systems that have been in place for many years.”