Building energy audit case study
Helping Stourbridge Glass Museum tackle an £80,000 energy crisis
How energy data, heating controls and a commercial building energy audit revealed the real causes of exceptionally high electricity use
Stourbridge Glass Museum was facing severe financial pressure after its annual energy costs increased from around £20,000 to approximately £80,000.
The museum needed to understand why the building was consuming so much electricity and whether it could reduce costs without compromising collections, staff, visitors or day-to-day operation.
What began as a short piece of emergency energy advice developed into a full commercial building energy audit .
The investigation found that the museum did not need an entirely new heating system. It already had efficient air-source heat pumps, but hidden controls, unsuitable settings and extensive use of direct-electric heaters were preventing the system from working effectively.
The situation
An organisation facing an immediate energy-cost crisis
Stourbridge Glass Museum approached Oxford Energy Services during the energy-price crisis after its electricity costs had increased to a level that threatened the organisation’s financial viability.
The operational challenge
Like many smaller cultural organisations, the museum did not employ a dedicated energy manager.
Responsibility for the building sat with a team whose primary expertise was in glass, collections, visitors and the day-to-day running of the museum rather than heating systems, controls or energy data.
Numerous wall-mounted electric panel heaters were being used throughout the building. Staff could switch them off, but other occupants could switch them back on whenever rooms felt cold.
Why the heaters mattered
One heater could cost around £34 per day
At the exceptionally high electricity rate the museum was paying at the time, even one 2 kW electric heater could cost around £34 if left running continuously for 24 hours.
With numerous heaters operating across the site, the cumulative financial effect was substantial.
Initial diagnosis
A simple first action created the space for a proper investigation
During an initial conversation with the museum’s building manager, Alexander Goodger, it became clear that direct-electric heaters were likely to be a major source of avoidable consumption.
Understand the immediate problem
The museum was under severe financial pressure and needed an intervention that could be implemented without waiting for a major capital project.
Control unnecessary heating
The immediate recommendation was to remove the fuses from unnecessary panel heaters so they could not be switched back on casually.
Investigate the whole building
The initial advice gave the museum sufficient confidence to commission a full building energy audit.
It was to stop expensive supplementary heaters operating without control while the underlying heating and energy-management problem was properly investigated.
Building energy audit
What the investigation examined
The audit combined a detailed site investigation with analysis of the museum’s half-hourly electricity data.
Heating systems
Review of the air-source heat pumps, direct-electric heaters and how the different systems interacted.
Controls and schedules
Assessment of heating setpoints, controller accessibility, opening hours and overnight operation.
Half-hourly data
Analysis of electricity consumption during opening hours, closed periods and the highest-use winter days.
Practical improvements
Identification of operational, maintenance and capital measures in a clear order of priority.
The audit included
- Existing heating systems
- Air-source heat-pump operation
- Direct-electric panel heaters
- Heating controls and temperature settings
- Opening-hours energy use
- Out-of-hours and overnight consumption
It also considered
- Lighting efficiency
- System maintenance
- Operating schedules
- Renewable-energy opportunities
- Collection-storage requirements
- Future capital improvements
The main finding
The museum already had an efficient heating system
The problem was not the absence of efficient heating. It was the way the existing systems had been set up and operated.
The museum already had two large Daikin air-source heat-pump systems, but staff were barely aware of them.
Their controllers were obscured by a display and the heating temperature had been set to only 15°C.
Staff and visitors naturally felt cold, so direct-electric wall heaters were switched on throughout the building.
The additional heat then caused the heat pumps to reduce their output or stop, meaning that the least efficient heating option displaced the more efficient system.
Heat pumps attempted to maintain only 15°C.
Staff and visitors felt cold.
Direct-electric heaters were switched on.
The extra heat reduced the heat-pump output.
Expensive electric heating displaced efficient heat-pump heating.
“The museum did not need an expensive new heating system. It already had efficient heat pumps, but the controls were hidden, the settings were unsuitable and direct-electric heaters were stopping the system from doing its job.”
Half-hourly energy data
The building used almost as much electricity while closed as while open
Analysis of the museum’s consumption profile exposed the scale of the out-of-hours problem.
Why this mattered
A building that consumes almost as much electricity while unoccupied as it does during normal operation is likely to contain significant avoidable base load, overnight heating or poorly controlled equipment.
This is why a building energy audit needs to connect the physical building with its energy data. A normal daytime walkthrough alone may not reveal what continues to operate overnight.
Read: Why out-of-hours energy use mattersPractical recommendations
Improve existing systems before investing in replacements
The priority was not an expensive refurbishment. It was to make the museum’s existing heating and control systems work properly.
Immediate actions
Stop the most avoidable waste
- Disable unnecessary direct-electric heaters
- Increase the heat-pump heating setpoint
- Make heat-pump controllers accessible
- Separate heating and cooling settings
- Prevent systems working against each other
Low-cost improvements
Improve operation and maintenance
- Programme heating around actual opening hours
- Review half-hourly data regularly
- Investigate unusual overnight consumption
- Clean internal heat-pump filters
- Maintain external heat-pump units
- Assign responsibility for controls
Longer-term measures
Assess investment in the right order
- Replace remaining electric heaters where appropriate
- Review lighting efficiency
- Evaluate solar photovoltaic proposals
- Review server energy use
- Consider collection-storage conditions
- Plan future glass-studio electrification
The outcome
The central problem was solved by understanding the building
The museum did not have to begin by purchasing an entirely new heating system.
The combination of immediate advice, half-hourly data analysis and a detailed commercial building energy audit gave the team a practical route through the energy crisis.
The museum was able to remain operational and subsequently went on to receive four environmental awards.
What changed
Better information led to better decisions
- The team understood where electricity was being used
- Excessive out-of-hours consumption was identified
- Reliance on direct-electric heating could be reduced
- The existing heat pumps could be operated more effectively
- Low-cost actions were prioritised before major investment
- A more informed approach to energy management was established
The wider lesson
High energy use does not always mean a building needs new equipment
In many commercial buildings, avoidable energy use results from a combination of controls, schedules, maintenance and operational behaviour.
Unsuitable settings
Efficient equipment can still perform badly when temperatures and schedules do not reflect how the building is used.
Inaccessible controls
Building users cannot manage systems effectively when controllers are hidden, confusing or poorly understood.
Systems working against each other
Supplementary heaters, cooling and central plant can interact in ways that increase rather than reduce consumption.
Out-of-hours consumption
Energy data can reveal equipment operating overnight, at weekends or during periods when the building is empty.
A building energy audit connects site investigation, energy data and technical judgement to show what the building is actually doing and which actions should be prioritised.
Related services and sector support
Support for museums, cultural venues and complex buildings
The Stourbridge Glass Museum project brought together building diagnosis, energy-data analysis, heating controls and practical follow-through.
Building Energy Audits
A detailed site and data investigation to identify where energy is being wasted, what is causing it and what should be fixed first.
View Building Energy AuditsVenues, Collections & Historic Places
Sector-specific support for museums, galleries, theatres, heritage sites and visitor buildings with operational or environmental constraints.
Explore the relevant sector pageEnergy Management Support
Ongoing review of energy data, controls, proposals and actions to help prevent problems returning.
View Energy Management SupportAudits & Energy Insights
Practical guidance on energy data, hidden waste, controls, building investigation and deciding what to prioritise.
Explore Audits & Energy InsightsContinue exploring
Related case studies and practical energy insights
Explore how the same evidence-led approach has been applied across a complex historic estate and the wider UK cultural sector, alongside the Myth Busters most closely connected to this project.
Does out-of-hours energy use really matter?
Why closed periods, night-load and overnight heating can reveal major sources of avoidable consumption.
Read the Myth BusterIs energy waste always obvious?
Why controls, schedules and apparently normal building operation can conceal significant waste.
Read the Myth BusterDo you need a major retrofit to reduce energy costs?
Why better settings, controls and operation may need to come before expensive replacement projects.
Read the Myth BusterCase study FAQs
Questions this project helps answer
What did the Stourbridge Glass Museum energy audit find?
The audit found that existing air-source heat pumps were being undermined by a low heating setpoint, inaccessible controls and widespread use of direct-electric panel heaters.
Why was the museum using so much electricity while closed?
The energy data indicated significant out-of-hours consumption, including heating and other systems operating when the museum was unoccupied.
Did the museum need a completely new heating system?
No. It already had an efficient heat-pump system. The immediate priority was to improve settings, controls, maintenance and the use of supplementary heaters.
What does a commercial building energy audit include?
It can include a site inspection, analysis of electricity and gas use, review of plant and controls, investigation of out-of-hours consumption and a prioritised energy audit report.
Explore Building Energy AuditsCan half-hourly data identify hidden energy waste?
Yes. Half-hourly data can reveal overnight base load, unusual peaks, weekend operation and equipment continuing to consume energy when a building is closed.
Should capital investment always be the first response?
No. Controls, settings, schedules, maintenance and staff understanding should be investigated before assuming that expensive replacement equipment is required.
Why Oxford Energy Services
Technical judgement grounded in real building experience
Oxford Energy Services is led by Dr Russell Layberry, a physicist and building energy consultant with practical experience in energy data, building services, controls, heat pumps, audits and energy action planning.
The work combines technical analysis with a practical understanding of how buildings are actually operated.
Free 30-minute discussion
Concerned about high or unexplained building energy use?
A technically led building energy audit can identify where energy is being consumed, what is happening outside working hours and whether existing systems are operating correctly.
The aim is to distinguish genuine investment needs from problems that can be resolved through better controls, operation, maintenance and monitoring.
Prefer to learn more first? Explore Building Energy Audits or view all OES case studies .
Contact Russell
Email:
russ@oxfordenergyservices.co.uk
Phone:
+44 (0)7803 397 549