When you wander the parking lot at the car dealership, dreaming about your next ride, each new car has a Monroney sticker on it explaining the features and details of the vehicle. It's a standardized sticker and it allows you to understand those features at a glance. The largest font is reserved for gas mileage – city and highway, and, interestingly, one of the smallest fonts is the price of the vehicle.
Here's an image of the 2012 Chevrolet Volt's Monroney Sticker.
The sticker was developed by Almer Stillwell "Mike" Monroney, a senator from Oklahoma who sponsored the Automobile Information Disclosure Act of 1958. In the 1970s, the EPA added fuel economy standards to the sticker, and starting this year information about the energy electric vehicles use – kWh, emissions, and other environmental aspects will be added.
Regardless of your requirements of a car, we all have a basic understanding of the value of good gas mileage versus bad gas mileage, and the Monroney stickers provides useful information so we can balance those needs pretty quickly. Based on the number of really big SUVs and much more efficient smaller cars I see on Route 93, I think that disclosure tool works well. The gas guzzlers are usually the ones zipping past me, all urgency and comfort, using even more fuel. And so it goes, but at least they knew what they were buying.
When we consider buying a building – new or used, residential or commercial – we are usually first interested in the cost, the location, the size and features as well as the appearance. Operational costs sometimes come up in the conversation, but the other factors often outweigh them in immediacy. And rarely do we really know what we bought until those first utility bills arrive. Considering that in New Hampshire 59% of our energy is used in and for buildings, it is a serious shortcoming that we do not give more thought to the annual energy consumption in buildings.
Currently, there is no Monroney-energy sticker for buildings, although there are some very smart people working to develop one. The Multiple Listings Service sheet available through real estate professionals offers many of the details of buildings, and recently the Northern New England Real Estate Network added a box on their MLS sheet for "building certifications." This box often remains blank because most buildings cannot claim certifications. The empty box provides a placeholder to acknowledge above-code certifications such as EnergyStar, HERS, LEED, Green Globes, Passive House, Net Zero, or some other accomplishment. The box's emptiness signifies that the building isn't as optimal as it could be. This placeholder provides a very important first step, and until all buildings have a metric that we can understand at a glance, many building owners are going to be continually surprised at their operational costs.
From a sales perspective this makes perfect sense because most of the building stock leaves a lot to be desired when it comes to energy efficiency. No salesperson seeks to highlight the inadequacies of their product. It takes a much more creative sales approach to acknowledge long-term costs and the burdens they may bring a building owner. The language of real-estate sales can be a bit of a parallel universe, with code words like "great location," "charming," "cozy," and "a handy man's dream" euphemistically telling the real story.
Many commercial buildings are owned by one entity and leased by another in a triple-net lease arrangement, whereby the tenant pays not just rent but also all of the costs of running the building, including the taxes, insurance, maintenance, and utilities. This scenario provides little motivation for the building owner to make energy-related upgrades, because he/she doesn't pay those costs or recoup the savings. The tenant isn't motivated to make improvements either because he/she doesn't own the asset. This "split incentive" also effects residential rental units and leads to the gradual decline of the buildings.
Some banks now require HERS Ratings (Home Energy Rating System) before lending on residential Energy Efficient Mortgages (EEMs) or "green mortgages." All ENERGY STAR certified homes must earn a HERS Rating of approximately 85 or lower, depending on a variety of factors such as square footage. Banks that participate in EEM programs may lend at more attractive rates and value certain upgrades that are not included or valued in standard mortgages. These measures can include aggressive airsealing and insulation, more efficient heating or cooling systems, ventilation systems, ENERGY STAR certified appliances, renewable energy systems, and high-performance windows and doors.
The HERS Rating process confirms that energy-efficiency upgrades have been modeled and installed as designed and that energy use will be lower than its baseline comparison; the bank and the owner are confident that the monthly utility bills will be less than a code-built house, thus reducing the risk of default because of operational costs. Therefore the bank can lend a little more money on the building and/or at a better rate, and that additional amount to the mortgage covers the costs of the upgrades.
A HERS Rating of 100 represents the baseline energy code for a new home and 0 denotes net zero energy use. There are a lot of factors and analyses that need to be considered to arrive at a HERS Rating, and for the most part this metric is used for residential construction. The US Department of Energy has determined that a typical resale home scores 130 on the HERS Index. An average 1900s farmhouse would probably get a HERS Rating of 150 to 200, but why would they want to advertise that? A normal 1970s house would probably get about 120. A house built to the 2009 International Energy Conservation Code should get a HERS Rating of 100. This is the building energy code standard we use in New Hampshire. However, energy-code compliance rates in New Hampshire average about 50%, meaning that new construction does not always meet the expected standards.
Most ENERGY STAR homes, which also require the HERS Ratings, in New Hampshire, are in the 60-70 range without renewable energy systems. There are a handful of very high-performing homes in the mid-20s. The figure below provides the HERS scale along with some typical values.
England has developed a two-certificate system, one that denotes the modeled expectations of the building and the other that discloses how efficiently the building is being used. This is a really interesting approach. Much like a speed-demon driving a very efficient vehicle, buildings that are operated differently than the energy models anticipate and will thus have different outcomes. As the advertisements remind us, "your results may vary".
But what about existing buildings? What about larger commercial buildings, the real energy hogs out there? For these structures, building science professionals use energy intensity metrics – Energy Use Intensity and Cost Use Intensity, although they are not as visible (yet) as those Monroney stickers.
Energy Use Intensity (EUI) is an easy metric to understand: Thousands of BTUs per Square Foot per Year. By collecting energy bills for the entire building – electricity, space heating, hot water heating, process heating, and, if incurred, the costs to dispose of waste heat – for one year and converting all of the energy units into one unit of measure, thousands of British Thermal Units (kBTUs), we can compare electricity and heating loads as well as year-to-year usage. Some buildings use a mix of fuel sources for heat and they have different units of measure – for example, electric (kilowatt hours) for space heating, propane (gallons) for domestic hot water, #2 or #6 fuel oil (gallons) or natural gas (therms) or wood pellets (tons) for heating. By converting all the fuels to one common unit, it is much easier to analyze. In our analysis, we prefer looking at three years of data to get a full grasp of energy use in the building. It is important to also realize that different types of buildings – hospitals, schools, apartment buildings, retail stores and warehouses all have different energy profiles and should therefore not be compared to buildings in general but rather to buildings of similar type.
To better explain this we will use, as an example, a mixed-use retail and apartment building, 32,635 square feet in size, heated with oil. The following chart is an analysis completed prior to making energy-efficiency upgrades. While a lot of us focus on our electricity rates, in fact in New Hampshire we rarely use electricity for heat, but rather use a tremendous amount of fossil fuels, as shown in the consumption chart below.
Let's be honest, though, only a few of us really care about energy waste because it is waste, most of us care about the associated costs, and this is where it gets very interesting. Cost Use Intensity (CUI) uses the same utility bills, but instead of energy metrics, we analyze the dollars spent on energy. The metric here is Dollars per Square Foot per Year. The chart below shows this data broken out monthly, to better understand how the seasonal changes effect energy consumption.
This is when the dynamics of fuel costs enter the conversation. These days, a building heated with oil costs ~4 times more per BTU than one heated with natural gas or about double the cost of wood pellets. These factors lead to important fuel switching decisions. For example, the long-range forecasts on wood pellets – not to mention the other positive attributes of local and renewable fuels compared to fossil fuels – are relatively stable and supply is available. Switching to wood pellets will therefore dramatically reduce the costs for heating.
EUI and CUI information can be compared to data on similar building types. It is important to understand, however, that this baseline comparison work is relative to existing buildings. Did I mention yet that our existing building stock is very inefficient? Ergo, a decent result through a benchmarking exercise might be a winner in a slow race of poorly performing buildings.
Such benchmarking can be quite motivational for building owners who are considering Deep Energy Retrofits (DERs), comprehensive projects that will significantly drop the energy use in the building, improving costs, comfort, and occupancy. Often times, when building owners realize how much worse their buildings perform compared to otherwise similar buildings, a competitive side of them surfaces and they want to undertake a DER project.
A DER project typically seeks to reduce energy use by 50%, and it can happen in phases over a number of years. This is most easily achieved in the poorest performing buildings because as buildings improve, the cost to make such percentage reductions gets harder, a la diminishing returns. Typically, a DER will include a package of comprehensive measures such as airsealing and insulation, HVAC and distribution system upgrades, controls, lighting, perhaps windows or door, and renewable energy systems, such as solar hot water and/or wood pellet heating. This example building underwent all of these upgrades. Operator training to run the new and more sophisticated systems is key to success. Moreover, it is critical to monitor and verify that the systems perform as designed and installed – and working together! – and that on-going commissioning ensures that the systems continue to operate smoothly.
In the example shown below, the building started out with an EUI of 89.18 and after the DER it dropped to 30.2. The CUI value dropped from $2.64 to $1.40/square foot.
An interesting metric being used by building scientists to compare the energy performance of buildings across regions incorporates Heating Degree Days into this calculation. This normalizes the energy numbers in a way so we can compare the heating use in a New Hampshire building with one in a very different climate location. This step is helpful in comparing buildings across regions and climate zones., (Electricity and Cooling Degree Days are often similarly considered in warmer climates.)
The metric is : BTU / Square Foot / Heating Degree Day.
Using the example above, this metric would create a single number – yippee! – that could be used on buildings across the country to demonstrate their energy performance and it could in time become as effective as a Monroney sticker on a car. This particular building started out at a value of 13.5 and and after a deep energy retrofit now celebrates a value of 6.0. This is very exciting and demonstrates what can be accomplished in reducing the energy efficiency of our building stock.
These building energy efficiency measures are growing in popularity as they allow us to determine operating costs for buildings, benchmark existing and new buildings as well as measure the outcomes of energy savings projects. Energy is all about the numbers and these are good metrics that allow us to measure our progress and perhaps one day they will be as prevalent as the Monroney stickers on new cars.
Laura Richardson
5/14/13
Laura Richardson
5/14/13
Laura Richardson is Director of Operations at The Jordan Institute in Concord, NH. The Jordan Institute, an energy think tank, mission-driven to find solutions to climate change, helps commercial building owners significantly reduce the energy used in their buildings. She managed nine energy programs funded by the stimulus for the NH Office of Energy and Planning, coordinated the StayWarmNH initiative, and co-founded the NH Sustainable Energy Association in 2003. She and her husband have lived off the grid since 2001 in a PV-powered, passive-solar and cordwood/TARM heated home. The home earned a 54 HERS Rating. Her Toyota Prius has 288,000 miles on it and still gets between 45-50mpg.
(*One of her all-time favorite bands is Siouxsie and the Banshees. *"Happy House" is a great tune, full of irony and cynicism about how wonderful we pretend things are when really they are a mess. Sort of like our building stock. Enjoy Happy House!)
