Environmental Physicist Technical building energy expertise
20+ years Building energy experience
300+ Buildings audited or supported
ESOS-aligned Based on recognised audit principles

Building energy myth buster

Myth: Energy waste is obvious

In many buildings, the biggest energy waste is not easy to see.

A building can look normal during the working day while wasting energy overnight, at weekends, or through hidden control and operating issues.

The first step is not always buying new technology. It is understanding what the building is already doing when nobody is looking.

The reality

Energy waste often hides in patterns, settings and operating hours

Many organisations assume that if a building is wasting energy, someone will notice. Lights left on, heating too high, open doors or visible equipment running unnecessarily can all be easy to spot.

But in practice, a lot of building energy waste is hidden. It sits in heating schedules, ventilation run-times, controls, night-loads, equipment operation and patterns that only become clear when energy data is reviewed alongside how the building is actually used.

Where waste hides

A building can look fine and still waste energy every day

Hidden waste is often not caused by one dramatic fault. It usually builds up through small technical, operational and control issues that become normal over time.

01

Out-of-hours consumption

Electricity or gas use can remain high overnight, at weekends or during closure periods, even when the building should be largely inactive.

02

Heating schedules

Heating can start too early, run too late, or operate to schedules that no longer match how the building is used.

03

Ventilation run-times

Fans, air handling units and extract systems can run unnecessarily outside occupied hours.

04

Control overrides

Timers, sensors, BMS settings and manual overrides can drift away from the intended operating strategy.

05

Heating and cooling conflicts

Some buildings use energy fighting themselves, with heating and cooling operating against each other.

06

Lighting and equipment habits

Lighting, equipment and plant can be left running because “that is how it has always been set up”.

Energy data tells the story

The real pattern often appears when nobody is in the building

Daytime energy use can be difficult to interpret because many systems are legitimately running. Out-of-hours data is often more revealing.

If a building is empty overnight or at weekends, but still shows a high base load or significant heating, ventilation or electrical demand, that is a strong sign that something needs investigating.

Some of that energy use may be necessary. Some may not. The value of a proper review is separating essential use from avoidable waste.

Before spending money

Do not start with the solution before you understand the building

Energy efficiency is often treated as a technology problem.

Replace the lighting. Upgrade the heating. Install solar panels. Improve the controls. Add new equipment.

Sometimes those are the right actions. But they should follow a proper diagnosis.

A practical review helps answer:

  • Where is energy being used?
  • When is it being used?
  • Is that use necessary?
  • What does the pattern suggest?
  • Which systems should be checked first?
  • Which actions are quick wins?
  • Which capital measures are worth investigating?

The practical next step

Start with a Building Energy Audit

The 10-Point Building Energy Review

Oxford Energy Services provides a fixed-fee Building Energy Audit for organisations that need clear answers on where their building is wasting energy and what to do next.

The audit combines energy data, site inspection and practical building energy expertise to identify avoidable waste, highlight priority opportunities and provide clear next steps.

What the review looks at

A 10-point check of where buildings commonly waste energy

The review is designed to identify hidden waste and turn it into a practical action plan.

01

Energy data

Electricity and gas patterns, unusual consumption and evidence of avoidable waste.

02

Heating

Boilers, zoning, set points, schedules and heating control issues.

03

Cooling

Air conditioning use, simultaneous heating and cooling, and unnecessary operation.

04

Ventilation

Air handling, extract systems, fan operation and running hours.

05

Controls

Timers, BMS settings, sensors, overrides and poor control logic.

06

Lighting

Lighting type, zoning, occupancy patterns and control opportunities.

07

Hot water

Hot water generation, storage, circulation losses and usage patterns.

08

Building fabric

Heat loss, insulation, air leakage, glazing and obvious fabric-related issues.

09

Operations

How the building is actually used, occupied, maintained and managed day to day.

10

Action plan

Priority recommendations, likely savings, cost implications and next steps.

The outcome

A clear, practical route forward

You receive a concise summary of what is happening in the building, where the main opportunities are, and what should be done next.

  • Clear priorities
  • Practical recommendations
  • Evidence for action
  • Support for funding or retrofit planning
  • A focused route to lower energy use

This is useful if

You suspect energy waste but cannot see where it is

  • Energy costs are rising and you do not know why
  • You have half-hourly data but need help interpreting it
  • You want to understand night-load or weekend consumption
  • You need evidence before committing to capital measures
  • You want clearer next steps for energy reduction

Common questions

Questions organisations often ask before starting

Does hidden energy waste always show up in bills?

Not always clearly. Bills can show that energy use is high, but they rarely explain why. Half-hourly electricity data, operating schedules and a site review can provide a much clearer picture.

What is night-load?

Night-load is the energy a building uses outside normal occupied hours. Some of it may be necessary, but high night-load can also indicate avoidable waste from plant, lighting, equipment or control issues.

Should we install new equipment first?

Not before understanding the building. New equipment may be useful, but it is better to diagnose existing waste, control issues and operating patterns before committing to major spend.

Is the free 30-minute discussion a sales call?

It is a practical conversation about your building, your concerns and whether an audit is the right next step. If a different route is more appropriate, that can be discussed too.

Free 30-minute discussion

Not sure where your building is wasting energy?

Start with a practical conversation. If your building is showing signs of hidden waste, Oxford Energy Services can help you understand what is happening and whether a fixed-fee Building Energy Audit is the right next step.