Climate Change: Increasing City Buildings’ Energy Efficiency - Nine Questions City Officials Should Ask
Craig W. Hoellwarth is principal of GREEN INQ, a consulting ﬁrm that provides green/sustainable planning and design services, and can be reached at craig@GreenInq.com. John Deakin is senior energy and sustainability manager for HDR/Brown Vence & Associates, which specializes in solid waste management planning and energy management consulting, and can be reached at John.Deakin@hdrinc.com. Leslie Kramer is vice president of HDR/Brown Vence & Associates and can be reached at Leslie.Kramer@hdrinc.com.
As energy costs rise and widespread concern about climate change increases, cities can limit their greenhouse gas emissions and save money by reducing energy use in municipal buildings and investing in energy efficiency. This article explores questions city officials should ask about energy use and efficiency so they can make informed decisions about city buildings.
1. Why is energy efficiency in city buildings important?
The simple reasons are cost savings, energy and resource conservation, and the increasing public support for protecting the environment and reducing greenhouse gas emissions. Furthermore, leading by example sends an important message to your community and may stimulate "green" economic development.
2. What policies should guide energy decision-making?
Be sure to include a life-cycle cost analysis, which is a financial evaluation of alternative building design strategies that considers significant costs of construction and operation over the economic life of the facility. The analysis should include the:
- Capital (or initial) costs;
- Annual operating and maintenance expense expressed as a cost-benefit ratio;
- Payback period; and
- Rate of return on investment (ROI).
For example, when comparing the cost of two new heating, ventilation and air conditioning (HVAC) systems, don’t just look at the initial purchase price. Analyze the lifetime energy and operations costs, and determine which system saves more money over its lifetime. It may be better to pay a higher price at the front end in order to save more over the life of the system.
Your agency may want to consider adopting policies specifying that:
- No public or private building project shall be approved with less than a specified cost-benefit ratio, payback period or rate of ROI; or
- A specific percentage cost premium will be acceptable for strategies that have demonstrated improvements in employee performance, such as thermal comfort and indoor air quality.
3. What strategies are right for my building?
First, determine the building’s purpose and, if applicable, the project goals. This information will set the context and priorities for energy decision-making. The intention should be to use a minimum amount of energy to reach the building program’s established goals. Consider using "green" building guidelines that require an integrated architectural, engineering and facility management team and a "whole building" approach to facility planning and design, whether it’s new construction or an existing building. Because strategies proposed by one design professional might constrain those proposed by other team members, bring the team together to weigh the overall impact of different proposed strategies. Don’t forget to include facility management staff who will have to run the building after the designers’ work is completed.
4. How much money does the city spend on energy each year? Where does it go?
Identify who is responsible for reviewing and paying energy bills. Take steps to ensure that someone is responsible for energy management, and consider requiring building managers to regularly review the utility bills for their buildings. Chances are that every year 20 percent of the city’s buildings are burning up 80 percent of its energy budget. Most of the money goes to light, heat and cool those big energy users.
Start by making sure your energy-using equipment is operating only when it’s really needed. The easiest way to save energy is to switch it off. Then get help to make sure the lighting and HVAC systems are operating at maximum efficiency when you really need them. The utilities that serve your city can assist you with tracking energy and cost impacts.
5. We want to make our existing city hall more energy efficient. What should we do first?
Start with an energy audit, which will tell you what can be done to save energy in your city hall, how much each measure will cost/save and what the payback period is. Audits can identify steps that could reduce energy use by as much as 25 percent.
Opportunities for typical city hall retrofit savings lie primarily in lighting upgrades, "retro-commissioning" the controls, and replacement of very old (20 years or older) HVAC equipment. Upgrade lighting by changing to more efficient lamps and ballasts and installing occupancy sensors.
Retro-commissioning means testing the systems that control the building’s operation, primarily heating, ventilation and air conditioning systems, to verify they are working as designed. For example, significant energy can be lost if fans stay on all night or on weekends because programmable thermostats or central energy management systems are not functioning properly. If you have postponed replacing aging HVAC equipment, you can save on both energy and maintenance costs by replacing package units and chillers with newer equipment, which can be twice as efficient as the ones installed 20 years ago.
You don’t have to wait to see the results of an energy audit to take some immediate actions to reduce energy use. Remind your employees to turn off office lighting, computers and copiers at the end of the day and close windows when the air conditioning is on. Remind the custodial staff to shut off lights at the end of their shifts. Check that time clocks that control lights or fans are still set properly. These simple yet important steps can cut energy use by 5 percent.
6. We did an energy audit five years ago and implemented all of the recommendations. Does this mean we don’t need to do another one now?
No. There is value in doing another energy audit due to advances in technologies and new rebate offerings from utilities. For example, if you upgraded to T8 lamps and electronic ballasts in 2002, it may be cost effective to upgrade again to spectrally enhanced 5000K T8 lamps and premium electronic ballasts, depending on your specific lighting fixtures. New wireless control systems for HVAC make it more cost effective today than five years ago to convert constant-volume, multizone HVAC systems to variable air volume systems. New programs funded by the California Public Utilities Commission can help larger customers pay for retro-commissioning their control systems. These opportunities, which didn’t exist five years ago, include the Portland Energy Conservation, Inc., RCx statewide program (www.peci.org/about/4-rcx-fea.htm) and Energy Watch (www.abag.ca.gov/abagenergywatch), a joint project of the Association of Bay Area Governments (ABAG) and Pacific Gas & Electric Company in Northern California.
7. If the city’s new facilities are going to be consuming energy for the next 50 years, what should we be thinking about now?
Think about the long term when designing a new city facility. California’s Title 24 building energy standards will be updated again in 2008. However, it’s possible to go beyond Title 24 by designing buildings to take full advantage of passive de-sign concepts and use the most efficient lighting and HVAC systems available. For example, a detention center in a coastal climate that is built with high mass walls and high ventilation rates will have minimal need for mechanical cooling. Super efficient office buildings are now using "mixed mode" systems that combine natural ventilation through operable windows and/or ventilation with radiant cooling panels to minimize mechanical cooling. Some energy efficiency strategies increase initial costs, while others reduce initial costs by significantly downsizing mechanical and electrical systems, so be sure to incorporate life-cycle costing analysis.
8. Some cities are requiring all their new buildings to be LEED certified. Should we be doing the same?
The Leadership in Energy and Environmental Design (LEED) rating system was developed by the U.S. Green Building Council. LEED works by tallying scores in various categories, including site planning, water and energy management, use of recycled materials and indoor environmental quality, and has been adopted by many local governments. Annual reductions for LEED buildings average 30 percent for energy, 30 to 50 percent for water, and 35 percent in climate-changing greenhouse gas emissions. Many cities are adapting the LEED system to suit local conditions. For example, some cities do not require LEED certification, but use the LEED system to establish a minimum point level for permit approval.
9. How do we know the alternatives we select will perform and deliver results as expected?
One of the most important strategies for improving system performance is the commissioning of all building systems. This is the same process as retro-commissioning; the only difference is that it’s done when the equipment is installed. Make sure the contractor who commissions the equipment is an independent agent and not the same contractor who installed the system.
Other key strategies include ensuring that the intended system performance is a well designed, easily understood system that uses building controls (such as occupancy sensors and energy management systems) and ongoing energy and cost monitoring systems to track energy system performance.
Public buildings that are highly energy efficient and environmentally friendly don’t just happen. They are the result of thoughtful elected officials, public works officials, energy staff and architects asking the right questions at the earliest stages of project planning and design or redesign, and continuing that dialogue through project completion.
Remember, the questions in this article are a starting point. We encourage you to use them to help you and your colleagues become better educated so your city can make informed decisions about the energy future of your municipal buildings. If your residents ask whether your city incorporated energy efficiency in the design of the new city hall or if your city has retrofitted city hall to be more energy efficient, you will be able to say, "Yes, we did!"Edit Module