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Resource Center: Tools to Improve Building Efficiency

Increasing a building’s energy performance is a continuous process of improving both building operations and systems. The first step to examining and improving your building’s performance is to measure your energy performance with ENERGY STAR Portfolio Manager. From there, the process of improving energy efficiency will be somewhat different in each building, depending on current energy management practices and the age and efficiency of building systems. However, all buildings that improve their energy efficiency will do some combination of the following: See our Energy Efficiency Checklist for a summary. 

For more resources and information, select the relevant drop down below:

The Energize Denver Energy Efficiency Awards were given to the three office buildings, three apartment buildings and three hotels that improved their energy efficiency the most from 2016 to 2017.  Here are the winners! please see the CREJ special Energize Denver supplement.

Offices:

1st Place: Tamarac Plaza, 1, 7555 E Hampden Ave. Cut energy use by 35 percent.

2nd Place: Havana Gold, 4880 Havana St. ENERGY STAR score improved from 26 to 43.

3rd Place: Market Center, 1624 Market St. ENERGY STAR score improved from 78 to 96

Apartments:

1st Place: The Lodge, 4710 E. Mississippi Ave. Cut energy use by 31 percent.

2nd Place: 1000 South Broadway, 1000 S. Broadway, ENERGY STAR score improved from 77 to 99.

3rd Place: The Denver House, 1055 Logan St. ENERGY STAR score improved from 86 to 96.

Hotels:

1st Place: Hampton Inn and Suites, 1845 Sherman St. ENERGY STAR score improved from 52 to 98.

2nd Place: Doubletree by Hilton, 3203 Quebec St. Increased ENERGY STAR score from 67 to 71.

3rd Place: Crown Plaza Denver, 1450 Glenarm Place. Cut electric use by 8 percent and natural gas by 13 percent.

Operating a building efficiently means:

  • Regularly checking that heating, cooling and ventilation systems are only running when needed
  • Lights are off after hours or when sufficient daylight is present
  • Thermostats, sensors, and controls are correctly calibrated and programmed
  • All other equipment in the building is working as designed.

These operational efficiencies can be maintained on a continuous basis using technology that automatically detects issues and fixes them.  If technology isn’t in place to automatically detect issues, a building can periodically go through a re-tuning, or retrocommissioning process, to systematically evaluate and find opportunities for operational improvements.

Learn about Xcel's Recommissioning programs. 

 

The first step in planning an upgrade to equipment and systems is to have an energy audit.  An audit will specify the energy savings and payback period that might be expected from replacing building equipment and systems.

Get started with an on-site energy audit from Xcel Energy, they will usually pay 90% of the cost of an ASHRAE Level 1/2  audit. Find an auditor and discuss next steps with Xcel Energy's business solutions center, 1-800-481-4700.

Learn about the types of energy audits available in this Building Owner Guide to Energy Audits.

info about audit levels 

Lighting Solutions for High-Performing Buildings

Energy efficiency in sustainable buildings is positive for the bottom line and important in retaining tenants and enhancing wellness. According to a U.S. Department of Energy study, green buildings deliver 28.8% greater net operating income (NOI) and have 17.6% less operating costs than non-green buildings. A Harvard study found LEED-certified buildings eliminated 21,000 lost days of work and 16,000 lost days of school per year. 

infographic about lighting befefits

The first step on the path to energy and cost savings in buildings is Energize Denver and benchmarking because you can’t manage what you don’t measure. From the Energize Denver data we’re already on our way and buildings over 25,000 square feet saved 4% from 2016 to 2017. Results for 2018 will be out soon! You can save money and help meet Denver’s climate goals! Denver’s goal is to reduce building energy use 10% by 2020. 

How Can My Building Perform Better?

One of the first places to start thinking about a better performing building is by considering low-cost or no-cost energy savings upgrades. These include: efficient lighting, a tune-up of your building (operations, scheduling, temperatures), and training staff.  These are further outlined in Energize Denver’s Energy Efficiency Checklist

How Can I Improve My Building’s Lighting?

Efficient lighting is at the top of the list of energy upgrades because the payback is typically less than three years.  Lighting and considerations for daylight can also enhance spaces and decrease fatigue.  Cornell University found that workers in daylight office environments reported a 51% drop in the incidence of eyestrain, a 63% drop in the incidence of headaches and a 56% reduction in drowsiness.  There are a range of efficient lighting solutions for your building from first-steps to advanced ideas to innovative approaches.  These include: 

infographic about good, better and best LED lights

Good, First Steps – Install LEDs

Installing LEDs in your building is a great start. LEDs are currently the longest-lasting bulb. So while the initial cost is higher, they have a longer life than other lighting types and will need to be replaced less frequently. The payback is typically under three years for installing LED lights. And for most bulb types, this is an easy swap where you can simply replace the current bulb with an LED bulb. The table below details a cost and duration comparison of an LED vs. CFL vs. incandescent light bulb. One LED bulb costs $23 per year to operate compared with a CFL at $45 and incandescent at $186. How many lights are in your building? The savings can add up quickly.    

The Savings from Upgrading to a Single LED

 

LED

CFL

Incandescent

Initial Cost

$4/bulb

$2/bulb

$1/bulb

Lifespan

25,000 hrs.

8,000 hrs.

1,200 hrs.

# Bulbs (25,000 hrs*)

1 bulb

3 bulbs

21 bulbs

Bulb Cost (25,000 hrs)

$4

$6

$21

Cost of Electricity ($0.11/kWh)

$19

$39

$165

Total Cost (25,000 hrs)

$23

$45

$186

SAVINGS (from incandescent)

$163

$141

$0

*How much is 25,000 hrs.?  Just under 3 years if the light is on 24/7 or about 10 years if the light is on 9 hours/day during the work week (5 day/week)

To ensure an LED-replacement bulb performs as desired, consider the lumens (the illumination level) of the bulb, the temperature of the light (warm-red to cool-blue), and if the bulb is dimmable (detailed in the bulb specifications). The table below shows a comparison of brightness in lumens to show various types of bulbs with the wattage of each. The lower the wattage, the less energy the bulb will use and the less it will cost to operate. 

Light Bulb Brightness Equivalents

 Brightness

(lumens)

LED

(watts)

CFL

(watts)

Incandescent

(watts)

450

4-5

9-13

40

800

6-8

13-15

60

1,100

9-13

18-25

75

1,600

16-20

23-30

100

2,600

22-28

30-55

150


There are a few special considerations for an LED upgrade, which are specifically for replacing either linear fluorescent or HID bulbs. The reason? Ballasts. While there are plug-and-play LED replacements for both applications, the savings will be greater if you upgrade to either remove the ballasts or replace the fixture. Typical paybacks are still under three years when doing this as a full replacement or fixture upgrade because of the additional energy savings.

Better, Advanced Ideas – Include Lighting Controls

A more advanced approach to lighting is to add lighting controls in the form of occupancy and daylight sensors to an install of or upgrade to LED fixtures. The controls add flexibility in ensuring that lights are off during unoccupied hours and that spaces are properly lit with and without additional daylight through windows. The capital costs of upgrading to LEDs with controls typically have a one to three year payback range and are usually on the shorter side of that with automated controls. 

Best: Innovative Approaches – Mimic Daylight with LEDs  

Lighting design is increasingly more sophisticated with a variety of benefits. “The Employee Experience” Study by Future Workplace found that 78% of employees say access to natural light and views improves their well-being and 70% report improved work performance. 

Beyond installing LEDs and controls, building owners and managers can use controls to vary lighting temperature throughout the day to track more closely to daylighting. This strategy can reduce fatigue and increase productivity by scheduling lighting temperature by the time of the day. Below you can see the range of natural-lighting temperatures throughout the day, measured in Kelvin (K), starting with warm light, moving to cool white at noon, and back to warm light at sunset.  

infographic explaining natural light by temperature

Another design methodology is to determine the lighting temperature needed based on the activity within a specific space. This scenario doesn’t require changing the temperature to match natural light, it matches the activity in the space to a lighting temperature. Lighting temperature has been shown to affect productivity by the color temperature of the light. Warm light is comfortable and relaxing, mid-temperature light is welcoming and can promote alertness, and cooler light enhances productivity and reduces fatigue.  

A commercial-lighting designer or consultant can also assist in designing lighting for your building, as well as incorporate both the latest technology and to consider lighting brightness, temperature, and color, based on the use of each space. 

Are the Financing Opportunities for Efficient Lighting? 

As mentioned earlier, lighting upgrades have a payback of one to three years depending on the lighting-design sophistication. There are generally two approaches to financing lighting upgrades. One approach is to view energy upgrades for your building incrementally. Start with the low-cost and no-cost items, such as lighting. Then, budget for more complex (and expensive) upgrades in the future. To assist with lighting upgrades, a wide range of rebates are available from Xcel Energy.   

Another approach, especially when HVAC-equipment upgrades are needed in your building, is to wrap multiple energy-efficiency upgrades into one large upgrade package. While this has higher up-front costs, financing options like the CPACE program are available to support substantial energy-upgrade packages. The Colorado CPACE program has case studies available detailing successful projects. 

Final Thoughts

Lighting demonstrates a commitment to sustainability to tenants, occupants, and owners. Whether restaurants are using warm lighting to replicate candlelight for relaxation or office spaces using cooler light to mimic daylight to enhance productivity and reduce fatigue, lighting is integral to the use of a space. Upgrading to energy-efficient lighting results in lower operating costs for buildings with happier tenants. Saving energy through efficient lighting is a bright solution for profit, people, and our planet.

Equipment and systems can be replaced at the end of their useful life or ahead of schedule.  It may make financial sense to replace some building systems and equipment immediately, as newer equipment has an attractive payback period based on the estimated energy savings.  For other equipment, it may make sense to wait to replace the unit when it reaches its end of useful life, at which time more energy efficient equipment can be selected.  

 

What is the Payback on Typical Energy Efficiency Improvement Strategies?

Source:  "United States Building Efficiency Retrofits: Market Sizing and Financing Models." Rockefeller Foundation and Deutsche Bank Group. 2012. Payback periods are estimates, there are no assurances that payback periods will be achieved.

Through Colorado Commercial Property Assessed Clean Energy (PACE), property owners and developers across Denver will be able to access a new financing tool to invest in energy efficiency, renewable energy and water conservation improvements. The voluntary program lowers the cost of third-party financing, which is repaid through the property tax assessment process. Participants receive capital to finance eligible improvements, and repayment is collected through the property tax assessment process (a voluntary assessment is placed on the building owner’s property tax bill). The assessment can provide long-term financing of up to 20 years and stays with the property at the time of sale, removing traditional barriers to financing projects with payback cycles longer than two to three years.
 
The of advantages of PACE for owners of commercial real estate include:

  • No down payment or personal loan guarantee needed from the owner
  • Energy cost savings can be cash flow positive to the owner
  • Building asset value is increased by the value of the new equipment
  • When the property is sold, the lien transfers to the new owner (like a sewer tax)
  • Long-term (up to 20 year) financing is available at low fixed rates from local and national capital providers

The of advantages of PACE for the people of Denver include:

  • New jobs created by every C-PACE project
  • Energy consumption reduced through more efficient buildings
  • Greenhouse gas emission reductions

Resources

The following case study buildings are leading the way in improving energy efficiency. Learn how buildings like yours are staying ahead of the curve and seeing an attractive return on investments in energy efficiency. 

If you have recently undertaken or completed an energy efficiency project, we want to hear about it! Write a case study about your project or host an event with us to showcase your building. Please send suggestions for energy efficiency case studies and buildings we might showcase to energizedenver@denvergov.org. Read basic case study requirements.

Performance Contracting

From 2014 to 2017, General Services worked on a Performance Contract at fourteen City facilities, including libraries, recreation centers, and fire stations. The General Services Sustainability Fund received a total of $113,769 worth of rebates from Xcel Energy for investing in energy-saving equipment at these locations. Between January and November of 2017, an estimated energy use reduction of 17 percent was realized at these fourteen facilities.

Energy Star Certified Buildings

In 2017, nine City facilities received Energy Star certification. In general, Energy Star certified buildings release 35 percent less carbon dioxide into the atmosphere and use an average of 35 percent less energy than typical buildings. To earn Energy Star certification, a facility must operate among the top 25 percent of similar facilities nationwide, without sacrificing occupant comfort or building quality.

Better Buildings Challenge

In December 2011, Mayor Hancock committed the City and County of Denver to the Department of Energy’s Better Buildings Challenge initiative. Its goal is to reduce energy use per square foot by 20 percent by the year 2020. Despite increasing occupancy at City owned buildings, the City realized a 9 percent reduction in energy use per square foot in 2016, compared to our 2011 baseline energy use per square foot.

American Council for an Energy Efficient Economy – Top Ten Ranking for Denver

Denver was in the top ten in the 2017 ranking of community energy efficiency, done by the American Council for an Energy Efficient Economy, and was identified as a “leader in efficiency in local government operations” within a group of five cities with policies to increase the energy efficiency of municipal buildings.

http://aceee.org/local-policy/city-scorecard

http://aceee.org/press/2017/05/cities-boost-efforts-reduce-energy