How Much Does a Commercial Building Energy Audit Cost?

What does Oxford Energy Services charge for a building energy audit?

Oxford Energy Services offers a fixed-fee Building Energy Audit for £1,500.

The service is designed for one commercial building and includes practical investigation of:

• electricity and gas use;
• available half-hourly electricity data;
• night-load and out-of-hours consumption;
• heating, cooling and ventilation;
• lighting;
• controls and Building Management System settings;
• plant and operational issues;
• quick wins;
• capital measures worth investigating;
• clear recommendations and next steps.

The purpose is to provide a practical diagnosis of the building rather than a generic list of energy-saving measures.

Why do commercial energy audit prices vary?

Commercial buildings differ considerably. An audit of a straightforward office with standard operating hours may require a different level of work from an audit of a theatre, historic estate, multi-use site or building with specialist environmental controls.

The price may be affected by:

• building size;
• number of buildings;
• building type;
• complexity of plant and controls;
• number of energy meters;
• quality of available energy data;
• operating hours;
• specialist systems;
• number of stakeholders involved;
• travel and site access;
• required level of calculation;
• whether additional monitoring is needed;
• the format and depth of the final report.

This is why two quotations for what appears to be the same service may differ substantially.

Building size and complexity

Larger buildings generally take longer to inspect and may contain more plant, controls and operational zones. However, size alone does not determine the audit cost.

A large warehouse with simple systems may be easier to investigate than a smaller building containing multiple heating zones, local air-conditioning, specialist equipment, mixed occupancy and several control systems.

Complexity is often more important than floor area. The auditor may need to understand not only how the equipment is intended to operate, but also how it behaves in practice.

The amount and quality of energy data

The quality of the available data can affect both the audit process and the reliability of the findings.

Useful information may include:

• monthly electricity and gas bills;
• half-hourly electricity data;
• meter readings and sub-meter data;
• Building Management System trend data;
• operating hours and occupancy records;
• previous reports;
• contractor information;
• details of recent changes.

Where good data is available, the auditor can often identify patterns before the site visit and use the visit to investigate likely causes.

Where data is incomplete or inconsistent, more time may be needed to establish what is happening. In some cases, additional monitoring may be recommended.

Number of meters and operating hours

A simple building may have one electricity meter and one gas meter. A complex site may include several supplies, landlord and tenant meters, sub-meters, renewable generation, heat networks or separate meters for specialist equipment.

The more fragmented the energy picture, the more work may be required to understand where consumption occurs and whether the available data can be reconciled.

Operating patterns also affect scope. A conventional weekday office may have clear occupied and unoccupied periods, while other buildings may operate early, late, at weekends, around events, seasonally or continuously.

The auditor may need to review:

• when plant starts and stops;
• whether schedules match occupancy;
• whether weekends resemble weekdays;
• whether temporary overrides have become permanent;
• whether the building has an unusually high baseload.

Site visit requirements

A meaningful commercial building energy audit will usually include a site visit.

The auditor may inspect:

• plant rooms;
• boilers and heat pumps;
• pumps and fans;
• ventilation systems;
• lighting;
• local heating and cooling;
• meters;
• controls;
• Building Management System screens;
• areas with different occupancy or comfort requirements.

The amount of time needed on site will depend on the building’s size, layout and complexity. Access can also affect the scope, particularly where plant rooms require escorts, specialist areas are occupied continuously or several responsible people need to be consulted.

A quotation should be clear about how much site time is included.

Depth of analysis

Not every energy audit offers the same level of analysis.

A more detailed audit may include:

• half-hourly data analysis;
• baseload assessment;
• seasonal comparison;
• estimated annual savings;
• cost calculations;
• carbon calculations;
• payback periods;
• prioritisation;
• investigation of controls;
• comparison of proposed projects;
• recommendations for further monitoring.

The greater the level of calculation and technical review, the more time the work is likely to require. However, a longer report is not automatically a better one.

Fixed-fee audits versus day rates

Fixed-fee audit

A fixed fee gives the organisation a clear price before the work begins. This can be useful where the building falls within a defined scope, the deliverables are clear and the organisation wants budget certainty.

The quotation should state what is included and what might require additional work.

Day-rate consultancy

A consultant may charge by the day where the building is unusually complex, several sites are involved, the scope is unclear, extensive data analysis is required or the work forms part of a larger project.

A day rate can be appropriate, but the organisation should still understand the likely number of days and expected outputs.

Multi-site pricing

For multiple buildings, the price may be based on:

• a fee per site;
• a reduced fee for similar buildings;
• desktop analysis followed by selected site visits;
• an estate-wide review;
• prioritisation of high-consuming or unusual sites.

What should be included in the fee?

Before accepting a quotation, confirm whether the price includes:

• an initial discussion;
• review of energy bills;
• half-hourly data analysis;
• preparation before the visit;
• site inspection;
• meetings with relevant staff;
• travel;
• analysis after the visit;
• the written report;
• cost and saving estimates;
• prioritised recommendations;
• a presentation or follow-up meeting;
• clarification after the report is issued.

A quotation that appears cheaper may exclude several of these elements.

It is also worth checking whether the work includes independent advice or whether the provider also sells equipment or installation services.

Should the cheapest quotation win?

Not necessarily. A lower-priced audit may be appropriate for a simple building with a narrow scope.

However, a quotation should be judged on:

• the auditor’s experience;
• the proposed methodology;
• whether a site visit is included;
• the quality of the data analysis;
• understanding of building systems;
• independence;
• clarity of deliverables;
• the usefulness of the final recommendations.

The cheapest report may prove expensive if it leads the organisation towards the wrong project or fails to identify avoidable waste.

How much can an energy audit save?

There is no single guaranteed saving from a commercial building energy audit.

The outcome depends on:

• how efficiently the building already operates;
• the extent of hidden waste;
• the quality of existing controls;
• operating hours;
• the organisation’s willingness to act;
• the cost of implementation;
• whether recommendations are followed through.

The value of an audit is not only the amount of energy saved immediately. It may also help the organisation avoid unnecessary capital spending, challenge weak contractor assumptions, prioritise limited budgets and establish a stronger business case.

Beware of savings estimates that look too certain

Energy-saving estimates depend on assumptions about operating hours, current efficiency, future energy prices, occupancy, weather, control behaviour and maintenance.

A proposal may present a precise annual saving, but the figure is only as reliable as the assumptions behind it. The audit report should make those assumptions visible.

Does an audit always lead to major capital spending?

No. Some of the most useful findings may involve:

• correcting schedules;
• removing overrides;
• changing set points;
• repairing sensors;
• switching off unnecessary equipment;
• reducing weekend operation;
• clarifying staff responsibilities;
• improving routine data checks.

It is often better to optimise existing systems first, then use the resulting evidence to decide whether larger projects are justified.

Should solar panels come before an energy audit?

Solar PV can be a valuable investment, but generation and efficiency are different questions.

Before installing solar panels, an organisation should understand:

• how much electricity the building uses;
• when it uses it;
• how much is consumed outside operating hours;
• whether the baseload is justified;
• whether avoidable demand can be reduced first;
• how much generated electricity is likely to be used on site.

Reducing waste before sizing a solar installation can improve the quality of the investment decision.

When might additional work cost more?

A standard audit may identify areas that require further investigation where:

• sub-metering is absent;
• temporary monitoring is required;
• specialist controls need detailed review;
• equipment cannot be accessed during the visit;
• several buildings are included;
• detailed design is required;
• investment-grade calculations are needed;
• contractor proposals need technical review;
• the organisation wants implementation support.

The initial report should distinguish between actions that can proceed immediately, recommendations requiring quotations, measures requiring further design and areas where more monitoring is needed.

Audit cost versus audit value

A commercial building energy audit should be treated as a decision-making tool.

The cost should be considered alongside the potential value of:

• identifying hidden waste;
• reducing unnecessary energy use;
• avoiding unsuitable capital projects;
• improving control;
• supporting budget decisions;
• creating a prioritised action plan;
• giving senior management clearer evidence.

If an audit identifies plant operating unnecessarily every night and weekend, the resulting saving may continue year after year. If it prevents an unsuitable investment, the avoided cost may be even more significant.

Questions to ask when comparing audit quotations

• Is the price fixed or based on a day rate?
• How many buildings are included?
• Is a site visit included?
• How much time will be spent on site?
• Will half-hourly data be analysed?
• Will night-load and weekend use be investigated?
• Will the auditor review plant, controls and schedules?
• Are travel costs included?
• What will the final report contain?
• Will costs, savings and paybacks be estimated?
• How will uncertain savings be presented?
• Will recommendations be prioritised?
• Is a follow-up meeting included?
• Is the advice independent?
• What additional work might be recommended later?

Is a commercial building energy audit worth the cost?

An audit is most likely to provide value where an organisation:

• has unexplained or rising energy use;
• has not reviewed out-of-hours consumption;
• is unsure which project to prioritise;
• is considering major capital spending;
• has inherited poorly understood controls;
• manages a complex building;
• needs clearer evidence for senior management;
• does not have an in-house energy manager;
• has an existing report but limited progress.

The audit is less valuable if the organisation is not prepared to provide data, give access to the building or act on the findings.

Start with a clearly defined scope

The price of a commercial building energy audit should reflect the building, the available evidence and the level of investigation needed.

A useful quotation should explain:

• what will be reviewed;
• what will happen during the site visit;
• what analysis will be completed;
• what the report will contain;
• what is outside the scope;
• what the organisation can expect to do next.

Oxford Energy Services offers a fixed-fee Building Energy Audit for one building at £1,500, focused on practical diagnosis, clear recommendations and prioritised action.