Introduction | Impact of Decisions | Key Concepts & Best Practices | Commercial Buildings | Residential Buildings | Industrial Buildings | Acknowledgements

Key Concepts and Best Practices

Building decarbonization includes five main components: electrification, best-in-class energy efficiency, smart buildings, on-site renewables and/or grid integration, and design process.

Electrification

Our electricity is steadily becoming cleaner as utilities shift to more renewable energy and retire fossil fuel sources, and as homeowners and companies install renewable power on their buildings. Switching appliances and heating sources from natural gas and propane to electric energy reduces fossil fuel use. These changes substantially reduce GHG emissions without sacrificing the quality of heating or cooling for your building. The two most substantial electrification technologies, heat pumps and induction ranges, are notably more efficient than their gas counterpart.

To meet Colorado’s clean energy goals, all new buildings need to utilize efficient electric equipment, and roughly a quarter of all existing buildings need to be converted to primary heating with electric heat pumps by 2030. To achieve this, we need to retrofit 3-5% of our buildings every year, a substantial increase from the current rate of approximately 1% per year.³

While the task seems monumental, shifts in Colorado’s gas consumption can have a sizable impact. If 15% of direct natural gas use in residential and commercial sectors switched to electricity, and the increased electricity demand is met with zero emission energy sources (e.g. wind, solar), Colorado would cut GHG emissions by 1.6 million metric tons by 2030.⁴

Improved Building Energy Efficiency

Improving building energy efficiency offers numerous benefits, including reducing energy and maintenance costs as well as ensuring occupant health and well-being through a subset of strategies that also improve indoor air quality. Building energy efficiency includes:

• Improving opaque building insulation

• Changing from incandescent or CFL light bulbs to LED bulbs and providing occupancy-based lighting controls

• Focusing on the largest direct use of fossil fuel in buildings: heating and cooling. Air source heat pump technology is a particularly efficient way to heat and cool, delivering two to four times more energy than the electricity consumed

• Sealed air leaks

• Reducing the heat loss through glazing and/or window replacements or retrofits while also mitigating solar gain

• Upgraded electric appliances (where possible, heat pump based) rather than gas powered

• Vacancy sensors tied to lighting and outlets

• Dedicated focus on reducing energy use of miscellaneous plug-in items

• Daylight maximization

• Using plug load occupancy controls to turn off equipment when not in use

The ENERGY STAR program, run by the Environmental Protection Agency, promotes energy efficiency for commercial buildings; in 2016, it helped businesses and organizations save nearly $10 billion in energy costs.⁵

In addition to benefiting the environment and people’s health, energy-efficient buildings typically have lower operating costs, better financing terms, command higher rents and occupancy rates for commercial buildings and yield higher purchase prices for residential buildings.⁶ All of this increases a property’s value, generating an internal rate of return of up to 25% on energy improvements.⁷ Improving energy efficiency often involves higher up-front costs than typical maintenance work, but these investments may have a shorter payback period. The U.S. Department of Energy estimates that the typical household can save 25% on utility bills with energy efficiency measures and up to 30% savings through improvements in regulating interior temperature.

Improved building energy efficiency also opens up the door to numerous building certifications which outwardly demonstrate progress to key stakeholders whether that be investors, occupants, employees, students or faculty.

Smart Buildings

Smart buildings optimize energy consumption by allowing an owner or tenant to remotely manage energy use in the building and communicate with the energy provider to assist in managing energy use during peak times. You may already have the beginning of a smart, grid-interactive building. Smart thermostats, like Nest or Ecobee, have the ability to manage an HVAC system remotely and to interact with the grid. Such thermostats use motion detection to determine when and where to provide heating or cooling. By communicating with the grid, smart thermostats anticipate periods of increased demand on the grid and will cool or heat the building in advance of peak energy use. This saves money and energy for both the occupant and the utility. Some utility providers even offer financial incentives to use a grid-interconnected product.

Smart thermostats are just one example of how smart buildings benefit the energy grid and consumers. Some other ways a grid-interactive building can reduce energy and costs include:

• Battery storage, which can offset higher utility rates when demand is high

• Thermal storage, which can shift the use of heating and cooling to times of day when utility rates or grid emission rates are lower

• Smart electric vehicle charging, optimizing when the vehicle is charged so that the owner receives the lowest rate

• Grid-interactive electric water heaters

Smart buildings create a two-way communication line between the user or occupant of a building and the grid. To learn more, click here.

Design Process

Reaching net-zero emissions for a building requires research and early planning. Incorporating low-emissions goals in the nascent design stages, for either retrofits or new construction, allows the property owner and contractor to achieve efficient clean energy strategies during construction and throughout the life of the building. This is known as a whole systems approach and is critical to achieving net-zero emissions in buildings. Thoughtful and early planning also maximizes the rate of return and minimizes costs along the way.

This integrated delivery model is equally applicable to existing buildings. A whole-building or systems approach provides the structure needed to optimize when upgrades are made, to decide which upgrades or planning choices to pursue, and to achieve a net-zero or low-emissions project in a cost-efficient manner.

To learn More about the Eco-District, click here.

If you are constructing a new building or doing a substantial retrofit, you may want to consider off-site construction to potentially lower costs and further your impact. There is a broad range of prefabrications and modular solutions that exist and should be considered. For example, off-site construction uses precast concrete which lowers building GHG emissions that come from embedded carbon in most building materials. Reducing the on-site construction schedule is not only a potential for cost savings, but it can also help speed to market, which benefits the owner.

Learn more about hybrid construction here:

• Examples of useful hybrid building technology >

• What is hybrid construction? >

• Hybrid timber construction >

• Hybrid concrete construction >

Retrofitting a Building to Achieve Zero Carbon

If you are planning to retrofit a building to achieve zero carbon, RMI (formerly known as Rocky Mountain Institute) and Urban Land Institute recommend the approach below to accomplish that goal:⁸

• Set Tangible Sustainability Goals
  Projects are successful when energy and sustainability goals are clear, actionable, within the desired budget, and well-known across the organization. At a minimum, set an energy target and a goal around financing and investment such as payback requirements for individual projects, desired impact on asset value, or internal rate-of-return requirements. Goals should be informed by a cursory analysis of the building portfolio to determine the amount of savings available from viable energy projects. It is very important for an entire organization, including its leaders, accounting, facilities, sustainability, and other functions, to participate in the goal-setting process from the start, as early buy-in from all stakeholders will make it easier to stay the course.

• Establish an Energy Baseline
  Once goals are set, the next step in improving a building’s performance is to understand how the building is actually performing so the team can track progress toward goals and identify opportunities. Most of the information to develop a plan can be gathered during a site visit, including:

  • type, age, and condition of equipment in the building, including HVAC equipment, lighting, controls, roof, windows, etc.

  • approximate window-to-wall ratio

  • insulation levels in the roof and walls and insulation weak points (from thermal imaging)

  • infiltration levels (from blower door testing); current utility rate structure (from utility bills)

• Plan Efficiency Projects
  Independent energy conservation measures can be no-cost, which means they generate savings immediately. Analyze the budget by assessing upfront costs versus savings over time. Some examples of energy conservation measures are 1) adjusting mechanical and lighting schedules to match current building occupancy; 2) adjusting heating, cooling, and lighting zones so consistently unoccupied zones aren’t conditioned, ventilated, or lit; 3) engaging and educating tenants by providing actual use data to inform occupant behavior; 4) controlling entry and exit (keep doors closed, encourage revolving door use); and 5) using window blinds to reduce heat gain in summer and allow heat gain in winter.

  More in-depth measures include load reduction energy conservation measures that reduce the building’s heating and/or cooling loads. These include strategies like building envelope improvements (adding wall or roof insulation, sealing for air tightness, adding window films and exterior shading devices, etc.), lighting upgrades (replacement with LED fixtures or bulbs, dimming capabilities, vacancy and daylight controls, etc.), and plug load reduction (implementing equipment sleep mode, metering workstations, upgrading equipment, swapping desktops for laptops, etc.).

  The cumulative effect of these projects is the ability to downsize to smaller, less expensive HVAC equipment when it is time for replacement at the end of its useful life. Implementing these efficiency projects should be planned out through a trigger event calendar. A trigger event calendar is a calendar of energy upgrades, linked with key asset improvement cycles. Triggers are the building life-cycle events that may enable a deep retrofit as a result of major building investments, changes in usage, or other events.

• Analyze Renewable Energy And Energy Storage To Determine How Much Energy You Need And Whether It Is Currently Cost-Effective.
  Renewable energy generation and storage prices are dropping quickly. Also, government incentives, such as rebates, discounts, or tax credits and deductions, change regularly, so an analysis from two years ago may no longer be helpful. Once a site has maximized building efficiency, building owners should offset energy consumption with renewable energy in this general order of priority: 1) pursue on-site renewable energy to the fullest extent; 2) pursue local community solar; 3) pursue other local off-site renewable energy options.

• Start Implementing Your Projects And Track Your Progress.
  Tracking the building’s actual energy consumption against its goal of net-zero emissions will help the owner to understand the progress that is being made. Installing submeters (energy meters that sit below a master meter) will enable performance tracking. This will allow the building owner to analyze where the energy upgrades may be falling short or exceeding the expected improvements.

• Installing Submeters (Energy Meters That Sit Below A Master Meter) Will Enable Performance Tracking Specific To Building End Uses.
  There are benefits to installing meters that can individually track the energy being used from different systems, including the HVAC system, lighting, and plug loads, to enable owners and operators to easily identify savings opportunities. Sub-metered information and a robust building controls system can continually improve the property’s performance and fine-tune building energy systems to ensure they’re always performing at their potential. You may also want to consider interval meters, which can show the load profile of the building every 15 minutes, to immediately spot spikes and take corrective action.

3 Cooperation is crucial to private-sector decarbonization, says Amazon sustainability head, RMI

4 Colorado’s Climate Action Plan Emission Targets: Illustrative Strategies and GHG Abatement Potentials, M.J. Bradley & Associates

5 ENERGY STAR Facts and Stats

6 Energy Efficiency & Financial Performance: A Review of Studies in the Market, U.S. Department of Energy

7 How much does energy efficiency cost?, Energy Sage

8 The approach has been modified for purposes of this handbook. To read the approach in its entirety, click here.