Improving an existing building starts with understanding how it operates today. Considering equipment condition, operating patterns, maintenance needs and occupant expectations together makes appropriate actions clearer. A roadmap turns that information into decisions and an implementation plan that can be tracked. When work takes place in an occupied building, operational continuity is also an important part of preparation.
Making the starting condition understandable
Energy and water records, system documents, maintenance information and occupant observations should be assessed together. It is important to establish whether the documentation reflects the building's current use. Changing operating hours or additional equipment may make an earlier calculation less representative of today's conditions.
An energy audit can help examine consumption and improvement opportunities systematically. Its scope depends on the building's characteristics and the decisions to be made. ASHRAE Standard 211 for commercial building energy audits describes a framework for consistent energy audit practice and reporting. ASHRAE — Energy audit and maintenance standards.
Reading consumption, cost and emissions separately
Consumption records show the energy or water used. Cost is also affected by the tariffs and contract terms applied to that use. Energy-related emissions calculations use relevant emission factors. A change in consumption should therefore not be assumed to produce the same proportional change in cost and emissions.
The starting assessment should explain which indicator answers which question. An understandable operating record shows the period, scope and basis for comparison alongside the total. This makes it easier to discuss why results from different sources may vary.
Setting priorities around the building's needs
Selecting a measure requires assessing its expected effect alongside its feasibility. Maintenance needs, equipment condition, occupant comfort and planned refurbishment influence the decision. Operating adjustments or maintenance may take priority in some buildings, while system replacement may require a broader review in others.
Comparing options under consistent conditions is useful at this stage. Energy modeling supports examination of the expected effects of different design or system decisions. Clear assumptions help the team assess the strengths and limitations of each option. A calculated result should not be presented as an implemented and measured saving.
Planning implementation and responsibilities
Improvements can be phased alongside maintenance and renewal plans. Discuss the conditions for each task, its effects on occupants and the checks needed afterwards. Retrofitting existing buildings can provide an opportunity to improve energy performance. U.S. Department of Energy — Existing building retrofits.
Each step should identify the responsible team and the expected record. Keeping design changes aligned with site implementation supports subsequent assessment. Recording how a resolved finding was verified also helps track outstanding issues.
Assessing results with operating data
Monitoring should not begin only after implementation. A record of the starting condition and subsequent operating data provide the basis for a consistent comparison. Changes in occupancy, weather or operating patterns should also be examined for their effect on the result.
Model predictions and measurements are different forms of evidence that help explain what was expected and what occurred. Regular monitoring, maintenance records and relevant checks support investigation of deviations. Intended system operation can also be addressed through an appropriate commissioning and verification scope.
Certification and AECO's contribution
LEED O+M provides an assessment pathway addressing the operational performance of buildings in use. Where certification is an objective, documentation and operating records should be planned alongside the applicable requirements. USGBC — LEED for existing buildings See our LEED O+M recertification article for the general process.
AECO's building energy modeling and optimization services support technical assessment of options. Relevant measurement needs can be discussed through testing and measurement services, and certification objectives through LEED consulting. Sharing existing records and planned refurbishment helps define an appropriate scope for the project.