Last month, 10 global corporations with significant office space in New York City accepted the Mayor’s Carbon Challenge for commercial buildings to reduce greenhouse gas emissions by up to 40 percent over the next 10 years.

The corporations will focus on energy efficiency in their interior office spaces and leased spaces through strategies such as IT efficiency, plug load reductions, space layout optimization, and lighting upgrades. The initiative is part of a larger program that engages private organizations and institutions to help reduce citywide greenhouse gas emissions by 30 percent by 2030. Each participant has agreed to track carbon emissions and create an emissions-reduction strategy.

Below, ECOSTRUCTURE talks with the two of the Challenge’s design advisors, Janice Barnes and Joan Blumenfeld of Perkins+Will’s New York office, about the implications of the initiative.

What is your role on the task force?
We’re part of the Technical Advisory Group. We initially helped the Mayor’s office to identify large-footprint tenants and their real estate representatives. Since these tenants can have a significant impact on carbon reduction, it’s important to first focus efforts on helping this group. After the Mayor’s Carbon Challenge tenant group was assembled, we agreed to provide ongoing support of sustainable design strategies and peer reviews of tactics, metrics, and case studies.

Do you think a 40 percent reduction in greenhouse gas emissions over the next 10 years is realistic for commercial offices?
It’s quite realistic, even though it requires significant and continued change. If you’ve seen the recent results on the 2030 progress, you know that the projections show that we’re tracking ahead of need. This basically means that we will be able to generate more capacity than demand in the near future. While that might not be such good news for coal and gas companies, it’s great news for greenhouse gas (GHG) reduction.

Also, New York is a city of older buildings, many of which have inefficient systems and curtainwalls, which presents a unique context for additional reductions compared to other cities. In addition, energy policies in the city are continually becoming better understood, which has organically resulted in landlords and tenants becoming more aggressive in the incorporation of these policies. The new energy law doesn’t yet mandate reduction, only documentation. However, in simply documenting and benchmarking their energy usage, landlords and tenants can more clearly see the opportunities for cost savings through energy conservation. Look at the Empire State Building’s current retrofit, as an example. The cost savings, particularly when coupled with corporate policies for social and environmental responsibility, are also increasingly motivating tenants to choose more efficient buildings during lease renewals or other moves.

What are the main steps corporations will need to take to achieve this?
The first major step is to establish a baseline. If corporations aren’t currently aware of their overall impact, it’s likely that they’re unaware of what choices they should make to reduce it. Once a baseline is established, each corporation will be able to define a unique GHG fingerprint. From there, each can determine which of the many tactics available will have the greatest return on investment. Depending on the building, the lease agreement, and other factors, there can be significant differences in the scale of influence that the distinct tactics will have. It’s kind of like establishing an exercise program; one size doesn’t fit everyone. Once you’ve considered the range of tactics, you can establish your own program, which we call a climate action plan in the case of tenants. The climate action plan sets the targets from the baseline and identifies the means to reduction over time.

Interior space makes up 40 to 60 percent of the energy use in commercial office buildings but is a historically overlooked component of energy efficiency in buildings. Why is that?
First of all, we’re still in a fairly nascent stage. Typically, leases only expire every 10 years or so, but widespread understanding of the societal and financial benefits of sustainable design has really only developed over the past five years. In addition, tenants are responsible for energy distribution, but not for the base-building infrastructure systems and building envelope, although their knowledge of these other areas is growing. Base-building renovations only happen every 30 to 40 years, typically either when equipment wears out, the building needs aesthetic updating, or a curtainwall starts to fail. Interestingly, New Yorkers are at a watershed moment, when many older buildings (particularly from the ‘50s, ‘60s, and even ‘70s) are needing major upgrades, which is resulting in tenants becoming more educated about the potential for energy conservation.

What areas of interior design present the best opportunities for energy and financial savings?
A large proportion of energy use comes from lighting, and the new NYC Energy Code is already making a big difference since it requires a sizeable reduction in watts used per square foot. Adoption of this code is currently triggered whenever a ceiling needs renovation, which is typically at a tenant’s lease turnover. So in New York, we are seeing a significant reduction in energy use just by tenants moving to newly renovated spaces, which include lighting systems that meet the new code.

Externally, the building envelope presents another opportunity for significant savings. Buildings that predate the era of early modern glass towers are actually pretty strong in terms of overall energy performance due to heavy masonry construction and limited glazing. Their punched windows are also easy to replace with newer, more energy-efficient models. Glass office towers that predate insulated windows are generally the worst energy offenders, often requiring complete curtainwall replacements.

Finally, upgrading building infrastructure systems is also critical. Modern HVAC systems with computerized building management systems can help in managing the energy load and in understanding the impact when something is not functioning well. Increasingly, other more modern distribution systems, such as demand-control ventilation, Energy Star equipment, water-side economizers, or heat recovery systems, can be retrofitted into older buildings and reap large gains in efficiency.

What types of innovative ideas do you hope to see come out of the Mayor’s Challenge?
Simply identifying where the problems lie is huge. It’s an innovation in itself to drive tenants to look more closely at their current energy footprint. It is only through fostering awareness that we can focus on the changes that will bring the greatest improvements. And this awareness will also help others who are not yet engaged in the current program in learning lessons that can be applied to their own efforts in the future. This double loop learning will enable a much greater population to tap into the ideas that come out of the Mayor’s Challenge.