When you’re already one of the pioneers in building sustainability, how do you keep your edge? You use training to keep your staff engaged in the strategies and work practices that make buildings green. That’s exactly what Vornado, one of the largest owners and managers of commercial real estate in the U.S., has chosen to do.

Vornado is part of a growing group of real estate owner/operators who fully understand the positive impacts of sustainable operations on the bottom line. They have 30 million square feet of LEED-certified space and 25 million square feet with the ENERGY STAR label. They have structured their sustainability department to be a core part of their operations, managing all utility and energy efficiency spending, but they are not resting on their laurels.

In years past, Vornado ensured that managers were trained on the ins and outs of LEED and operating staff earned BOC (Building Operator Certification), but this time around, they wanted something broader to get management and operations speaking the same language.

GPRO proved to be the perfect solution and complemented what they had already learned from the LEED and BOC classes. GPRO goes beyond the required LEED checklist approach and explains WHY different elements of sustainabilityare important and what building managers and operators should be doing in their buildings.

Vornado partnered with Urban Green and the International Union of Operating Engineers (IUOE) Local 94 to train their staff.  Vornado arranged time for the chief and assistant chief engineers to attend dedicated daytime GPRO classes at the union training facility and provided training space for the managers’ and assistant managers’ courses.

“GPRO is such a great course because it provides a whole new way for the chief engineers to look at—and be excited about— their work,” noted IUOE Local 94 training director Howard Styles.

Before classes began Urban Green worked with Vornado and Local 94 to ensure that the customized portion of the classes was the same for both groups – facilitating a common vocabulary throughout the organization.

The courses were well received and Vornado is already using some of what they found during the training to improve their work practices.

“We were thrilled to offer GPRO to Vornado staff.  Working with the GPRO team made everything so easy, even down to the logistics of getting the instructors and books. The curriculum was great – very comprehensive and engaging,” said Sukayna Paciorek, Vornado’s vice president of corporate sustainability.

GPRO was created to help organizations bridge the “green gap” between conventional practices which are still deployed at even the most forward-thinking organizations and green practices that will reduce operational costs, increase building value, improve occupancy and rental rates and create healthier indoor environments.

To learn more about how GPRO can help your organization, contact Matt Rolnick, GPRO Business Manager at mr@urbangreencouncil.org.

By the end of 2013, over 1,400 New York City buildings will have to comply with Local Law 87: Audits and Retro-commissioning, the second in a series of laws that make up the Greener, Greater Buildings Plan (GGBP).  In requiring buildings 50,000 SF or greater to perform periodic energy audits, the city hopes to encourage energy efficiency retrofits that typically result in significant energy and cost savings.

Buildings that need to comply with LL87 in 2013 must submit Energy Efficiency Reports demonstrating compliance by December 31, and every 10 years thereafter.

Last year, Urban Green created a Local Law 87 Compliance Checklist and User’s Guide to help property managers and owners understand the steps required to comply and get the most out of the process.  With support from NYSERDA and Con Edison, we’ve presented this information free of charge to over 1,000 building owners, managers, and operators.  That’s a lot of people but it’s not nearly enough.  We’ve undertaken a second round of outreach to more effectively pinpoint  property managers and owners who may need added support in complying with the law and re-tuning their buildings.

Here’s what we did:

For a similar educational program on Local Law 84, which required the same group of large buildings to benchmark their energy and water use, we reached out to owners and property managers overseeing the greatest amount of square footage. This methodology was carried over into LL87 outreach but with some slight modifications using lessons learned from the city’s Benchmarking Report  released last year.
First, we looked in detail at compliance rates for benchmarking and found geographic areas where compliance was much lower than the overall rate of 75%. We then reached out to Business Improvement Districts, various Chamber of Commerce locations, and neighborhood associations within these areas.

In addition, we looked at compliance rates by building sector and reached out to associations serving sectors with below-average compliance.

We’re optimistic that our combined efforts will improve compliance rates for LL87 in 2013 and subsequent years (10% of 13,500 affected buildings are required to report each year).

We continue to deliver presentations and share information about the law through our fantastic volunteer speakers bureau and Checklist mentioned above.  Please contact us if you need to find out how to comply.

The GGBP laws are truly a win-win, as they encourage building practices that reduce energy use and carbon pollution, lower operating costs, and create “green” jobs for New Yorkers who specialize in building audits and commissioning.  We think the tools we’ve developed go beyond helping property managers and owners comply with the law, adding value to the process. With an additional 12,000 buildings affected by LL87, we have our work cut out for us!

For more information on Local Law 87 please click here or email us to request an onsite presentation.

Now in its second year, the EBie Awards from Urban Green Council, USGBC New York, are a nationwide juried competition for people working in Existing Buildings who have made great strides in improving environmental performance but whose accomplishments may otherwise go unheralded. Like the Oscars, there are multiple awards – but instead of Best Actor (or Best Key Grip) we have categories like Shine A Light On Me for the best lighting retrofit, and The Reformed Drinker for water savings. It’s sustainability in buildings, but sexy, with a glitzy awards ceremony (held at the Hard Rock Cafe Theatre in Times Square) for finalists and winners.

This year, we have added a new award for those people who work in multiple buildings: All Together Now, which recognizes the most improved portfolio across multiple sustainability categories, including water, waste management, stormwater, materials use, indoor environmental quality, and tenant engagement. The award is similar to the The All-Rounder, which is for a single building, but is designed for entrants who own, operate, or manage a group of buildings and improve their combined environmental performance. We expect that some of the biggest real improvements (not per square foot, but total water or energy savings) will come from portfolios, simply due to their size.

Working across a portfolio doesn’t mean you do different things, but it does change how you go about it. On the positive side, there’s lots of opportunity for lessons learned as conservation measures are repeated over and over (and over and over). Economies of scale come into play: once,when buying occupancy sensors for a campus-wide renovation, I found the price dropped by more than half when ordering 1,000 sensors instead of 100. Repetition can improve efficiency as project managers, purchasing agents, suppliers, and contractors develop good habits, and once-innovative processes become routine. And it’s much easier to get project approval from the right people – building occupants and top management – with a proven track record of success within the same portfolio.

Of course, it’s not always easy “scaling up.”  Despite the benefits of experience, it can seem like every situation is unique in its own way. It can be very difficult to give individual projects the attention they deserve when trying to be effective across 10, 100, or even 500 buildings. And going big too fast can have real costs if inventory is purchased and then plans change or deadlines are missed. Finally, the sheer effort required to create change in multiple buildings at once can be daunting right from the outset.

That’s why we created the EBies All Together Now portfolio award – to recognize the special opportunities and challenges that come from managing a portfolio. We’re looking forward to honoring the people making it happen across a group of buildings. If that’s you, go to ebies.org to find more details about how to apply and the definition of award categories and portfolios. The deadline for submissions is February 26, and we’ll be honoring finalists and the winners in New York City on June 19, 2013. See you there!

On January 15 I had the bright idea to attend Let There Be Daylight, an event discussing a report (of the same name, released in December) showing that at least 114 million square feet of New York City office space can easily be retrofitted with advanced daylighting controls. The presentations and discussions took place at the New York Times Building, which actually uses this technology to cut both energy use and peak electric demand.

The report makes a persuasive case: since daylight is often strongest when needed most to cut building energy peaks (summer afternoons), and prices have dropped substantially (from ~$100/ballast 10 years ago ~$30/ballast now), daylighting can be accomplished cost-effectively. NYSERDA and Con Edison incentives can shorten paybacks further, reportedly in the 4-5 year range for new construction. Wireless sensors can help overcome the obstacles of working in existing buildings, where entering the asbestos- or insulation-laden ceiling cavity is to be avoided if possible. Since New York’s central business district has more office area appropriate for daylighting than Chicago and San Francisco’s central business district areas combined, this is a major opportunity that cut could NYC peak demand by 160 megawatts.

The report contains a fantastic roadmap for future installations. By focusing on occupant comfort first, mostly by reducing glare, buildings maintain light quality and views while managing heat gain and energy savings. Best of all, the research included actual energy monitoring of existing installations to prove the savings, and polled occupants to ensure satisfaction with their daylighting systems. Since New York City buildings will have to upgrade their lighting in accordance with Local Law 88, it’s worth considering cost-effective additions to basic upgrades at the same time.

While daylighting control may be near-future technology, it still takes commitment, capital, and good design and installation. That makes it worthwhile to consider some easier and cheaper strategies that don’t include daylighting controls: implementing lighting schedules, reducing overlighting through retrofits and task lighting, and installing simple occupancy sensors. In fact, the report’s results show that daylighting controls play a smaller overall role in savings than these inexpensive, straightforward, and proven ways to greatly reduce lighting loads. Don’t wait for advanced controls to hit your block to start staring at the lights!

Many thanks to Richard Yancey of Green Light New York (which hosted the presentation and panel, co-sponsored by Urban Green) and his co-authors Stephen Selkowitz (Berkeley Labs) and Adam Hinge (Sustainable Energy Partnerships) for a great event.

Germany has about 28,000 megawatts of installed solar capacity, despite its northern and somewhat cloudy location. At peak output, that’s about 14 Indian Point nuclear facilities. What has inspired so many people to install solar in Germany and other countries? Easy answer: “Clean Local Energy Accessible Now (CLEAN)” Programs”, where utilities sign long-term contracts with generators to buy their solar electricity. When producers are guaranteed a good price for their output, investment quickly follows.

CLEAN programs have not been very popular in the US, maybe because they are generally known by an unappealing name: feed-in tariffs (sounds like a tax, doesn’t it?). Only about 100 megawatts of solar energy are supported this way nationwide. But that number increased by 50% in July when the Long Island Power Authority (LIPA) approved a CLEAN program for up to 50 megawatts of solar power in its area. This means that it will buy solar electricity at 22 cents per kilowatt-hour, for the next 20 years.

It’s a good deal for both the generator and the utility – that price is more than most people pay on average for electricity, but less than the utility pays for peak electricity on the hottest summer days, when solar power is most useful and often plentiful. And over 20 years, that fixed price will have encouraged solar development (since investors will see good returns) but in the end will also be a great deal for the utility if prices rise above that amount – not a bad bet over a two decade timeframe.

If the price is set high enough to encourage solar investment, who’s bearing the cost? Answer: the ratepayers, who will support utility purchases of solar power through the power supply charge on their bills. The charge is estimated at about 44 cents/month for a “typical” customer, a 0.7% increase in the current power supply charge. In the long run, ratepayers may benefit from LIPA having locked in low supply pricing, since the power supply charge varies with the utility’s cost of fuel. And if distributed solar reduces peak system loads, avoiding the need to build expensive “peaker” plants, everyone wins.

At Urban Green Council’s Sepetember 1^st Wednesday program, Charles Feit of OnForce Solar called the LIPA program a “game changer”. He also added that the US is “a decade behind Europe” when it comes to solar power. However, there are still hurdles to be faced. One of them is permitting, which Charles described as his biggest headache in getting solar installed. LIPA has a great website describing the program and how to take best advantage of it – but the “fast track” process for the smallest systems still has 15 steps to follow. Large projects require a study before LIPA will approve them. And this program isn’t meant to let you sell back a few extra electrons from the system you already have on your roof. Systems have to be new, at utility voltage, and sell all generated power to LIPA – you can’t use any of it yourself.

Nevertheless, this is a big step in the right direction. CLEAN programs can increase solar generation capacity by working in tandem with programs where owners lease solar panels or simply buy the output from rooftop panels sited on their property but owned by a third party. All these mechanisms are needed because there are many situations where solar power is appropriate, but the details of each case vary widely.

Charles said that his company is doing a robust business installing solar capacity, with a low-risk, attractive rate of return. Further simplification of the permitting process is necessary to truly stoke the market, and start to catch up to that European 10-year lead. New Yorkers, you’ll have to wait for Con Ed to appeal to the state Public Service Commission before a similar program can happen in the City – but Long Islanders, the time to deploy solar is now.

Our firm has come across a way to substantially lower energy use in many commercial buildings using a simple, readily implemented measure. This observation arose from our work on two large energy conservation efforts for NYC office buildings.  The first was NYC’s Energy Conservation Capital program (the largest municipal program at that time) highlighted in this 1980s article. The other was our more recent effort to identify and implement energy efficiency projects in high-rise commercial buildings in New York City (August issue of ASHRAE Journal).  Despite the intervention of almost three decades, at least one large wasteful concern persists: the excessive amounts of outside air most buildings draw in through defective outside air dampers.

Though not always inexpensive, this is a relatively straightforward issue to correct and one that most building owners and managers should consider.

In one major office building, after the outside air quantities were field tested, we found that leaking dampers allowed several times more outside air in than that recommended by ASHRAE Standard 62.1-2007 (see Test Building 1 in Table #4 below, taken from our ASHRAE article). Even with ostensibly closed dampers, the leakage rate exceeded 40% in this building. Testing in subsequent buildings confirmed that a large majority of the ubiquitous 1960’s and 70’s commercial office buildings are over-ventilated, resulting in wasted energy, some for heating, but mostly for cooling.  Many of these dampers date from the original construction of the building.  Table #4 shows the results of air testing of a number of other properties.

Table #4: Excess outside air is common in older large, commercial buildings

If a majority of Manhattan office buildings have excess outside air quantities similar to Table #4, installing new dampers would significantly reduce wasteful energy use as well as overall energy costs.

Another measure connected with curbing excess outside air is demand controlled ventilation (DCV), a process for reducing the cooling and heating costs associated with excess air. It has wide ranging applications not only in office buildings but in hospitals, recreation spaces, auditoriums, museums and many other facilities. The DCV technique employs equipment that measures the freshness of air in a building, typically done by measuring carbon dioxide (CO2). Although typically associated with global warming, in this case CO2 turns out to be an excellent proxy for determining appropriate ventilation conditions. (Because people breathe CO2 out, the concentration of CO2 reflects the number of people in a space.) Typically outside air in New York City is 400 to 450 ppm of CO2. An occupied air environment is normally considered “fresh” when the CO2 level is less than 1100 ppm.  Clearly, unless tightly-closing dampers are in place, DCV will not be fully effective since it relies on being able to stop outside air exchange when ventilation is not needed.  Using Test Building 1 as an example, Figure #2 shows the extent to which installing low-leakage dampers can be key to the effective use of DCV.

Figure #2: Test Building 1 proportional outside air savings; low-leakage dampers vs. DCV.

Unfortunately, some dampers constructed by local shops are not always engineered appropriately.  The linkages and damper motors often do not properly close the large damper assemblies and the damper blades become deformed, further limiting closure.  Outside air dampers must be installed on a modular basis, with appropriately sized damper motors and linkages, to provide adequate torque to close the dampers leaktight. High quality dampers, properly installed and adjusted, are the key to reducing outside air to appropriate levels and employing DCV effectively.

Panelist David Ropeik at Cooling on Climate Change

Urban Green pulled together a fascinating conference last week on the current science of climate change, exploring how it is impacting the building industry and why polls reveal public skepticism on the subject.  The format included two excellent panels and a short keynote by the distinguished scientist and activist, Dr. James Hansen.  There was a lot of intellectual firepower on display, including fascinating data on perceptions of climate change from Lisa Fernandez at Yale, and deep discussions of the role of the building industry.  David Ropeik, a risk perception consultant and the author, most recently, of How Risky Is It Really? Why Our Fears Don’t Always Match the Facts, offered the most unexpected perspectives of any speaker and clearly challenged our assumptions about how to effectively message on climate change.

Ropeik walked the audience through the current neurological research on risk perception, all of which supports the sense many of us have had over the years- that something as abstract and slow moving as climate change does not appear to motivate most of us to change our behavior.  Ropeik points out that very few of the tools we use to assess risk are cognitive- most of them are subconscious.  Our brains are wired to focus on things that will impact us directly, right now or in the very near future.  Threats that are catastrophic are deeply important, but chronic issues barely register on our internal threat scale.  Most of us in the environmental community act as if the simple communication of additional knowledge will cause people to change their minds- the more facts people know about climate change the more they will be motivated to change behavior.  But a deep body of research (and probably if we are honest with ourselves and our own experiences) tells us this simply is not the case.  People are not generally motivated to significantly alter their behavior because of threats to other species, or threats to our own that are likely to occur years from now.  Mr. Ropeik’s distillation of this context colored all the other discussions at the event and made for lively discussion.  In this context, Mr. Hansens’ slides communicating the impact of climate change through bar graphs and statistical plots seemed, though intellectually rigorous and important research, seemed somehow not up to the task at hand.  Based on Mr. Ropeik’s presentation I came away with the overwhelming sense that we need to find new ways of communicating that humanizes climate change and describes how it will impact each of us directly.

Which is not to minimize the critical importance of Hansen’s presentation.  For those of us familiar with his work and the work of his colleagues on the IPCC it was exciting (though sobering) to see the latest research on climate change.  Hansen pointed out that we have increased the amount of atmospheric CO2 from 280ppm to 390ppm, with every indication that average global temperature will increase by 2 degrees within a century.  The last time this happened, sea levels were 15 meters higher than today.  Already, significant changes are moving through the system.  The extent of arctic sea ice at the end of the melt season, as reported elsewhere, is reduced by half.  And the sea ice is significantly thinner, so the actual mass has been reduced by three-fourths.  This is a monumental shift that augurs more changes to come.  In addition, the % of land mass that experiences extreme weather events annually (droughts, flooding, fire) has increased 10 times since about 1920.  Dr. Hansen’s primary concern today are impacts that might be irreversible- like losing the ice sheet altogether, or a melt off of the Greenland ice sheet, or climate zones that move so fast that it triggers mass extinctions and failing ecosystems.  These are sobering but very real possibilities in our near future.

To produce a reduction in greenhouse gases Dr. Hansen proposes a “fee and dividend” policy that would ramp up a tax on carbon emissions and distribute the collected money equally among the population.  The funds would not go to the government and if current subsidies were removed it would level the technological playing field.  With our political establishment locked in a sweaty wrestling hold that allows for considerable activity but no resolution, it is highly unlikely that Hansen’s proposal will be enacted, or even discussed seriously.  But considering such a proposal allows us, at a minimum, to contemplate the high degree to which our current system is reliant on petroleum, and the significant degree to which the “market” is currently weighted in favor of the fossil fuel industry- which dominates energy subsidies despite being wildly profitable and flexes its lobbying muscle to influence almost every aspect of federal and state energy policy.  As Dr. Hansen stated, “the government should not be in the business of picking winners and losers.”  His fee and dividend proposal would remove the embedded advantage of the wealthiest industries and if ramped appropriately would spur innovation. Activism and individual action, Dr. Hansen points out, are wonderful but without a price signal that makes carbon emissions pay something like their share of externalized costs there will be little movement on the issue.  In fact, he seemed almost concerned that making buildings and other users of energy more efficient simply reduces demand and drives the price of oil down, incentivizing others to burn it.

Some years ago, Gore Vidal recommended that the world would be considerably improved if we simply swapped the cost of a university education with the cost of an intercontinental airline ticket- thereby making education available to all and significantly reducing the swarms of tourists senselessly marauding the globe.   Whatever the merits of this improbable idea, Dr. Hansen’s “fee and dividend” proposal might go a long way to achieving Vidal’s dream.  In a world where there is no tax on aviation fuel- the “market” will have to change significantly for us to re-assess how we do things. Without a bold move like carbon tax it is difficult to feel confident about our prospects for combating climate change.  As we wait (hopefully not in vain) for such a solution to gain traction, it is heartening to consider how much we now know about how our brains function. Amory Lovins likes to say, “The good news about climate change is that it is cheaper to fix than it is to ignore.”  The bad news might be that we are not well equipped to deal with it.  Despite this, I found myself invigorated as I left the conference.  We are truly beginning to understand how, at a primal, subconscious level, we respond to long range threats. This knowledge suggests a way of crafting our messages that might actually compel a majority of us to take the threat of climate change seriously.  Nothing could be more important, though I can’t expect my saying that to change your mind.

Friends tipped us off to a study recently featured by the Garrison Institute. Researchers from Fraunhofer’s Center for Sustainable Energy Systems found that user-friendliness and energy savings don’t necessarily go hand-in-hand with programmable thermostats. They called these results “both surprising, and suggestive.” (The presentation can be found here.)

Surprising? Not really. Anyone who has every tried to convince their family to try CFLs, or heard their friends discuss how they leave the AC on all day so their home will be cool when they return in the evening, knows that the ease of making a simple change often has little effect on getting people to do it. . Even when people care about and understand the importance of energy savings, they still forget to turn things off when they leave the room. It’s not at all surprising that they don’t set a programmable thermostat, no matter how intuitive it may be.

But suggestive, yes. The presentation covers the three basics of behavior change: motivation (the user wants to change something), ability (the user has the power to change it), and a trigger (they are reminded to actually do it). Programmable thermostats supply the ability, but not necessarily the motivation or the trigger.

In the end, the authors come to the correct conclusion themselves, in the very last bullet point of a 25-slide presentation: “Have technology replace motivation and triggers.” Automation. That’s right, humans, you’re being taken out of the loop and replaced with a computer. Nowadays, occupancy sensors can tell a smart thermostat when a room is empty, and the thermostat can use that information to control AC units, radiators, and lights.

While convincing occupants to manually program their thermostats is a long shot, using occupancy sensors successfully is a slam dunk; current technology can automatically set back heating and cooling temperatures when spaces are unoccupied. These devices originally came from the hotel industry, but are well suited to offices, dorm rooms, small apartments, and any space with single-room HVAC zones, making them a great fit for vast swathes of New York City real estate.

For wall- and window-mounted AC units and for radiators, these devices have been shown to have a 2-3 year payback in NYC. About half the savings is in the heating bill and half in the cooling bill – savings that can amount to up to 30% of the total in the first year after installation.

Using a passive infrared sensor to detect when the room is occupied, the devices don’t turn off accidentally when an occupant is sleeping or still. When a room is empty for a certain time, perhaps 15-30 minutes, they set back the temperature for energy savings. Good ones can also be programmed for an even deeper setback after 24 hours of vacancy, assuming the occupant is gone for the weekend or on vacation. Savings are guaranteed, regardless of occupant behavior or whether they care about energy use.

When the room is reoccupied, the control turns the heating or cooling on again to return the space to the desired setpoint. In summer, occupants may notice the temperature is not what it was when they left, but since the AC is already blowing cold air, they are generally satisfied. The AC may cycle on occasionally to prevent humidity from building up that could cause mold or other issues. In winter, the heat turns back on again as soon as a person comes into the room, and the unit maintains a specified minimum temperature even during long vacant periods.

Three things to look for when you’re shopping for occupancy-based HVAC controls:

1)   Recovery-time based setbacks. Rather than set back a fixed amount (say, 10°F), a good system will let you set the amount of time it will take for the room to reach a setpoint after it’s reoccupied (say, 10 minutes). A microprocessor decides how much to let the temperature “drift” during vacancy periods, so that a shaded room on the north side of a building might be set back more deeply than a sunny south facing room. This allows for the greatest energy savings – and the least discomfort for the people in the space.

2)   Networked controls. Modern units will “talk” to a central system, with a dashboard allowing analysis and control of units remotely. This allows management to troubleshoot problems before tenants complain, for even greater energy savings and fewer maintenance headaches. For example, AC units that run 100% of the time but can never bring the room to setpoint probably need maintenance. (Or, the window might be open. Luckily, these systems can be “interlocked,” so that the AC turns off automatically if the window is open).

3)   Good smart thermostat design. Yes, the study shows that people don’t use their programmable thermostats, even if they are easy to use. But in occupancy-based systems, the automatic controls do the energy-saving heavy lifting. A clean interface and easy-to-understand controls make it easier for a tenant to turn the AC and heat on and off, and set their desired temperature. That saves everyone headaches.

This technology might be difficult to implement in single-family homes, large apartments, or anyplace with a central system serving the whole space. In that case, homeowners might use something like the Nest Learning Thermostat, and commercial owners might try a computer-based Building Management System (BMS) or Energy Management System (EMS).

But for simple spaces with simple heating and cooling systems, bring on the robots.

Today, the NYC Mayor’s Office of Long-Term Planning and Sustainability released the first annual New York City Benchmarking Report. This landmark effort is required by Local Law 84, the first law enacted by the Green, Greater Buildings Plan (GGBP), and covers 12,565 private properties (municipal buildings began benchmarking a year earlier and their first report was issued in November 2011).

The report is the result of a foresighted and heroic effort. According to the report, of all the buildings benchmarked by law in the US, Local Law 84 alone accounts for about 61% of the impacted square footage! The data will eventually be available publicly (although the first year of data collection for each building type – municipal, non-residential, and residential – is not), which will be a treasure trove of information for the analysis of the built environment. Overall, the report is a fantastic 30,000-foot view of the city’s large buildings, boiling down complexity into clear, easily digestible chunks.

Buildings’ energy use ranges widely – even within similar building types

Among the more fascinating analyses in the report is a consideration of the factors that contribute to energy consumption. Multifamily building energy use intensity does not vary much, perhaps because they have more similar use patterns to each other. On the other hand, building use intensity for office buildings varies widely.

Several factors appear to correlate with office energy use intensity. For example, higher density of occupants and longer operating hours correspond to higher energy usage. Larger office buildings tend to use more energy per square foot than smaller ones, but it’s not immediately clear if this is due to the intrinsic nature of large building construction (inability to use natural ventilation, simultaneous heating and cooling, and complex systems) or other factors.

Another correlation is with construction date. The report splits building ages by twenty-year increments, and finds that energy intensity has steadily increased over each 20-year period. In fact, offices built since 1990 use almost 40% more energy per square foot than offices built before 1930!

There are a few possible reasons why this might be the case:

1. Tenant Profiles

Tenants with high computer use or other advanced technology needs might select newer buildings. If so, actual end uses would have to made more efficient to see improvements. Building infrastructure changes wouldn’t be the answer. In commercial buildings, since 70% of energy use is typically from tenant spaces, this warrants serious future study.

2. Increase in building system capacity

Newer building systems tend to have more lighting and HVAC than older ones do. A 1920s-era office building may struggle to keep up with HVAC needs on a hot day, whereas a brand new office building may have overcapacity all the time, causing AC units to run less efficiently. This can be improved in new construction through better building load projection during the design process, ensuring the building is geared to actual loads and not “rule of thumb” overestimates, as addressed by the Green Codes Task Force recommendation EE-2 Improve Analysis of Heating & Cooling Needs During Design).

3. Building system complexity

New buildings are more complex than older ones, with computer management systems controlling advanced, interrelated technologies. Sometimes these advancements save energy, but paradoxically, these complex buildings sometimes perform worse than their simpler brethren. Programs like GPRO, Building Operator Certification, Building Performance Institute Multifamily, and others address this maintenance and operations issue. In this case, we do have a hope of improving these buildings over time, as more emphasis is put on energy-efficient maintenance and operations. Benchmarking can help in this regard, since as tenants become more informed and look for the energy score of prospective spaces before leasing, owners will hopefully respond and attempt to improve their buildings’ performance.

4. Building envelope

Building envelope styles change over the decades. Newer buildings with high vision glass curtainwall construction may exhibit worse energy performance than older, masonry buildings with less window area. And though window energy performance has improved over time, we’ve given back those gains through greater increases in vision glazing area. This is one of the reasons the Green Codes Task Force is hoping to address new building envelope u-values in recommendation EF-3 Limit Heat Loss Through Exterior Walls).

More on this topic may become clear when benchmarking data is released in September. Nevertheless, the fact remains that there is a wide variability in energy use intensity, due to age and many factors, even among similar building types. This demonstrates the improvement that is possible in the City’s building stock – although as the report’s authors state, the City as a whole is not currently moving fast enough to meet the 2030 goal of 30% citywide greenhouse gas reduction.

It’s impressive how much work went into the report. The benchmarking data will be a great source for analyses that will ultimately help New York City and the nation create and implement strategies to cut energy use and greenhouse gas emissions. Congratulations are due to all who contributed to this effort.

I was working on my income tax return last spring when I noticed something new: the banks in which I had stuffed my pitiful savings were not bothering to send me forms indicating how much interest I had earned. It was so little it was not worth reporting!  Look at any savings account and you’ll see you are getting 0.02% annual interest (or something like that). Even CDs and most T-bills are around 1%. What’s a thoughtful, savings-minded person to do? You can go into the stock market and see higher returns, but you can also lose your shirt, which will make retirement chilly.

For homeowners and coop and condo boards, as well as solvent building owners, there is a reasonably secure alternative, and (of course) it’s energy efficiency, which amounts to a CD returning real interest, just like the old days, of 3% to 10% or more.

To see how this works, think about a CD.  You invest some amount of capital, say $1000, at some specified interest rate, for some fixed period of time, normally a few years. You can’t touch the money during that time without penalties, but at the end you get back your capital plus the earned interest. The only problem is that these days the earned interest isn’t worth your time going to the bank.

With energy efficiency, the structure’s a little different, but the result is much better. You invest some amount of capital, say $1000, in better lighting that will use less electricity. Because it uses less electricity, you save money on your electric bill every year. If your bill is $200 less than it would have been without the improvement, we say there was a simple payback period of $1000/$200 or five years.   So after five years you have gotten your investment back. But the new lights are still working and still saving $200 per year (or more if the electric rates go up). Suppose the lights will last for ten years – you will pick up another $1000 in the second five years of their life, for a total of $2000 in savings on a $1000 investment.  Ask your banker (or check the equations below) and you’ll see you got a 10% return on your investment over the ten years.  It’s not taxable, and you can’t get a return like that anywhere without selling your immortal soul.

Here’s the general formula: suppose you have an energy efficiency investment that pays for itself in P years. (P= payback period.) And suppose the installed system has a life expectancy of at least L years. (L = minimum system life.) Then the equivalent after tax interest is I = 1/P – 1/L.  This includes the obvious requirement that you get your capital back, just like with a CD.

Got CFLs? Payback P = 1 year, often. Lifetime L = 3 years. The interest rate on these 3-year CD equivalents is 67%!!  (I = 1/1 – 1/3 = 0.67.)

Of course, to actually end up with money, the way you do with a CD, you must have the fortitude to stick the savings into a bank and let them add up over the “L” years of the technology you have chosen. Even better, take the savings and invest them in some other energy efficiency improvement, and you will be compounding your interest in a way CDs can’t possibly duplicate. But I digress.

Again, maybe the nicest feature is that there is no 1099-INT, despite the serious levels of interest being earned!

The math:

K = capital cost ($)

A = Annual savings ($/year)

P = Payback period (years) = K/A

L = System lifetime (years)

Total income = L x A = L x K/P

Net income after capital = L x K/P – K

Net income after capital per year = (L x K /P – K)/L = K/P – K/L

Interest = net income after capital per year as fraction of capital

Interest = (K/P – K/L)/K = 1/P – 1/L