*Reposted with permission from the Department of Energy
Building renewal is “a commercial real estate strategy that significantly improves a building’s energy performance, revitalizes its market position, and increases asset value.” BetterBricks, a commercial building program of the Northwest Energy Efficiency Alliance (NEEA), developed building renewal with the goal of achieving energy use reductions of at least 35% in leased office buildings.
To jump-start building renewal, BetterBricks led a team of consultants and universities in developing Spark, a free online tool that project champions working in and around the commercial real-estate industry can use to quickly assess the economic and energy costs and benefits of building renewal projects.
Spark starts with a short screening questionnaire. Questions such as “Is building energy use considered too high?”, “Is the building at least 30% vacant?”, “Are major systems up for replacement in the next several years?”, and “Could innovative financing be used to supplement project costs?” identify good building renewal candidates—projects that combine suboptimal existing conditions with financing flexibility and opportunity to work with and around existing tenants.
For properties targeted for building renewal, the next step is developing an energy model that can be used to evaluate building renewal packages. BetterBricks created OpenStudio prototype models of mid-rise and high-rise pacific northwest office buildings. Spark collects more detailed information about the building, its physical assets, energy use, and tenancy and leasing structure and uses these inputs to modify the prototype models to match the candidate building.
This “seed” model serves as the starting point for evaluating energy conservation measures (ECMs). Spark allows users to select different combinations from a menu of upgrade options including envelope and window upgrades, lighting upgrades, lighting and occupancy controls, thermostat set-point optimization, and retrofits or complete replacements of hot and chilled water central plant equipment. Energy savings estimates are combined with cost estimates mined from past NEEA projects. Spark evaluates the chosen ECM package as well as a package that includes all applicable upgrades. These are summarized in reports that show the energy savings, the business case, and the assumptions behind each.
Although explicitly not an investment grade tool, Spark provides a holistic technical and financial analysis that spurs action. And once a project begins, Spark can act as shared workspace for stakeholders. Spark also provides descriptions of building renewal best practices to ensure that projects are carried out efficiently and deliver expected performance gains.
To implement Spark, BetterBricks turned to OpenStudio, DOE’s platform for developing EnergyPlus-based energy modeling applications. Specifically, they heavily leveraged OpenStudio Measures, scripts that can be used to apply ECMs to OpenStudio models. “We use OpenStudio’s Parametric Analysis Tool (PAT) to house the baseline model and to assess the energy savings impact of various ECM packages,” says Jeff Cole of Konstrukt, a consultancy that participated in Spark’s development. “We found a number of ready-to-use measures on the Buildings Component Library, we found several that we could modify to suit our needs, and we also wrote a number from scratch.” The complete Spark implementation is described in a paper that was recently presented at the 2016 ACEEE Summer Study on Energy Efficiency in Buildings.
Spark was informed and developed from four building renewal demonstration projects in the Pacific Northwest. One involved First Security Bank, a six-floor 23,000-square-foot building in Missoula, Montana. Here, Spark identified a $550,000 building renewal package that reduced both energy costs (by 46%) and maintenance costs while increasing rental income for a rate of return of 15%. “It’s easier for us to retain tenants and keep them happy. And it’s easier for us to recruit new tenants,” says building owner Carol Word. Michael Ballantyne, co-owner of Capital Gateway Plaza II building in Boise, Idaho, another building renewal project, adds, “The benefits of building renewal are not just about lowering your operating costs. It makes your equipment last longer, and your tenant retention is better.”