Energy-efficient designs for existing buildings

February 26, 2015 • Candace Wilson • Sustainable Design

With increased costs facing most business owners, many are scrutinizing their budgets for savings in facility operations. Lowering the energy costs of buildings is an important part of reducing these expenses.

Energy-efficiency is not limited to new construction; there are numerous strategies that can be applied to existing buildings. Reducing the need for electric lighting, using less water, plugging leaks in building walls, and adding insulation are four simple things to consider. Outside the building, proper site planning and landscape design are other things which may come into play.

To implement an effective energy-savings strategy for existing buildings, initiating a process of setting goals, establishing base line data, and getting the appropriate people “on board” is critical to it success. Gathering existing data on utility usage is an important first step in determining a baseline of current energy consumption. Often, architects and engineers can help building owners determine existing problems through computerized energy modeling and then help to establish appropriate goals for lowering energy consumption.

Through this integrated design approach, the owner, architect, engineers, and others work together as a team to consider and implement strategies to effectively reduce energy consumption and waste. The United States Department of Energy states that “An integrated design approach, where all parties involved collaborate on the building design was used to help…reduce…energy consumption as much as possible.”1 “An integrated approach to design ensures that each system compliments each other in a way to achieve optimal performance,” says Jeff Weiford, LEED AP BD+C, TESSERE Architecture, Inc. Designs often incorporate air-penetration barriers, high insulation values in windows, walls, and roofs, and efficient plumbing, heating and air conditioning systems. Shading, daylighting, and ventilation are also considered as part of the design effort.

Reducing energy dependency is paramount. Many different modifications can be made to an existing building. For example, a simple change of all 60-watt incandescent light bulbs to an equal output fluorescent bulb could save $30 per bulb, per bulb lifetime. These savings are calculated based on a 6,000-hour compact fluorescent light bulb (CLF), a 1,000-hour incandescent lamp, use of three hours per day, 11.09 cents per kilowatt hour electric rate, $3.00 per CFL, and $0.50 per incandescent lamp; essentially both a longer life, and less wattage.2

Operational issues are also important. For example, building managers can remind occupants to turn off lighting and electronics when not needed. This can be accomplished automatically by installing occupancy sensors to the lighting to shut off the lights when the building is unoccupied.

Through natural daylighting and photovoltaic cells, energy consumption can be reduced even more. By installing skylights to bring in light from the roof, or adding window shelves (solid horizontal elements placed above eye level, but below the top of the window) to diffuse the incoming sunlight and reflect it to a location that will better light the room, an existing building can bring in enough daylighting to dim and/or shut off areas that have enough light. In some cases, photovoltaic cells can be installed that dim or shut off lights when there is enough natural light coming into the area. Not only does this reduce energy, but it promotes a healthy work environment. Indoor environments have strong positive effects on occupant well-being and functioning, especially attributes such as the amount and quality of light and color. 3

Water reduction and usage is another consideration. Through innovative design, an existing building can be fitted to not only use less water, but also produce less waste, which lowers the need for water treatment facilities and for increased taxes. “The cost of a low-flow fixture versus an old-style high flow fixture is practically the same, so why not use one that will save money?” asked Mr. Weiford during a presentation of a recently completed project in Wichita, Kansas. The project also featured a rainwater reclamation system that collected rainwater from the roof and supplied all the needed water for the toilets and urinals. “Since the toilet water is 100 percent rainwater, the overall reduction of water use was a total of 83 percent,” said Weiford.

Innovative design to achieve energy efficiency is being fueled by business owners who want to spend less money on energy, which can be large operating expense – but does not have to be.

2 Why Choose ENERGY STAR? –
3 Promote Health and Well-Being –