Strategically Green - Developing a Retrofit Strategy: Making Sense of It All

Fall 2010

When developing a retrofit strategy, owners typically evaluate building condition and design, market conditions, and investment goals for the asset. When considering a sustainable renovation, it is particularly important that the decision-makers define their retrofit goals in order to prioritize the type of green upgrades to pursue.

From our experience, owners and operators would be most likely to consider sustainable strategies in their retrofit if they:

  • Reduce operating expenses cost-effectively on an ongoing basis
  • Increase the marketability of the property to prospective tenants and buyers
  • Create a more environmentally "sensitive" building if financially feasible

There are a variety of services, analytical tools and certifications to assist in realizing these goals, which can be overwhelming to even the experienced building owner. Even green building experts debate over the "best" approach of a sustainable retrofit – often depending on which service they are offering. In reality, given the unique characteristics of a project, there are not two or three "standard" strategies that would be applicable to a "typical" building retrofit.

The approach that offers the best cost/benefit ratio is to dissect the inner workings of a building, so that the true savings and value can surface. Take, for example, the goal of "reducing operating expenses on an ongoing basis." Regardless of scope and/or budget, every owner should have a basic understanding of their building’s performance. Portfolio Manager, a free online energy management tool developed by the DOE and EPA, tracks and analyzes building energy and water consumption and estimates greenhouse gas (GHG) emissions. For energy specifically, this tool rates a building’s performance on a scale of 1–100 relative to similar structures throughout the United States.

After recording this basic trend data, the next step is to investigate building performance in more detail. In this first of two articles, we will compare two very important analyses to consider before entering into a major consulting engagement or purchasing new equipment-- retrocommissioning and the commercial energy audit.

Retrocommissioning – Implementing a Building "Tune Up"

Retrocommissioning is the process of ensuring that systems in existing buildings are operating as efficiently as possible through: developing a building operations plan, conducting a variety of functional and diagnostic tests on building systems (such as HVAC, hot water, exterior walls, glazing, etc.), and implementing changes based on test results. Retrocommissioning is best applied when an owner is looking to maximize the building’s current systems without incurring major capital expense. This process requires a mechanical engineer or technician with years of experience in operation and maintenance of building systems.

Owners should be aware that a retrocommissioning scope of work can vary significantly in terms of tasks covered (i.e., list of findings vs. implementation of findings) and systems tested (i.e., HVAC only vs. whole building analysis). For an objective general description of the process, visit

Commercial Energy Audit – Planning a Building "Overhaul"

Similarly, a commercial energy audit is a broadly used term without one specific methodology. However, the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) audit procedure has become the most established standard, in part due to its adoption by LEED for Existing Buildings: Operations and Maintenance rating system (LEED EBOM). Per ASHRAE, the objectives of the audit are "to identify and develop modifications that will reduce the energy use and/or cost of operating the building." The best application is typically when the owner is looking for system recommendations that can be incorporated into a mid- to long-term capital needs plan but is not expecting actual repairs and/or changes from the study itself. See for more information.

There are four levels of audits, from a preliminary energy use analysis (similar to Portfolio Manager) to Levels I, II and III. The Level II audit provides a detailed energy and building analysis as well as cost, savings and payback recommendations and is the most comparable to retrocommissioning in terms of scope.

Below is a chart, which compares some of the features of these analytical tools:

With the information garnered from one of these analyses, the owner is equipped to develop a budget for the retrofit.

Item Retro-commissioning ASHRAE
Level II
Potential immediate impact on energy performance Yes No
Non-energy testing (i.e., indoor air quality, thermal comfort) Yes No
Testing of building envelope Yes No
Detailed energy use trend analysis No Yes
Detailed estimate of costs and savings of proposed measures No Yes
Estimated life of existing and new equipment No Yes
Development of operations manual Yes No
Identification of low/no cost measures Yes Yes
LEED EBOM potential points Up to 6 2
Payback period of analysis <1.5 yrs 5+*

* Longer payback due to greater emphasis on capital expenditures