Our high-precision commercial thermal imaging survey and fabric analysis visualised critical heat loss pathways and potential water ingress in this active shopping centre in Hertfordshire, providing the evidence needed to target an EPC B rating.
Project Summary
- End Client: The Marlowes Shopping Centre
- Property: A large, active shopping mall in Hemel Hempstead comprising retail units, offices and glazed atria
- Service: BREEAM Compliant Thermographic Survey
- Objective: To identify thermal bridging, air leakage paths, and insulation defects to support an uplift in EPC rating from C to B
The Challenge: Data Gathering in a Complex Environment
UEC Energy commissioned Building Energy Experts to support the decarbonisation strategy for The Marlowes Shopping Centre in Hertfordshire. The objective was to secure the necessary evidence to improve the site’s Energy Performance Certificate (EPC) rating from a C to a B.
Achieving this required a granular assessment of the building fabric to identify heat loss pathways. Due to the complex nature of the site—featuring unheated atria, segmented retail units, and extensive glazing—our team determined that a Thermographic Survey would offer superior diagnostic value over standard air tightness testing. The priority was to provide a visual map of physical defects for remediation.
Technical Execution
Surveying a fully operational retail hub presents unique logistical and technical challenges. Unlike vacant assets where environmental variables can be strictly controlled, The Marlowes remained in active use.
Our Head of Testing used a high-resolution FLIR E76 thermal imaging camera, strictly adhering to industry best practices (BRE 176, IP 1/06, and BS EN ISO 13187) to ensure data integrity:
- Environmental Control: The survey was executed across two sessions, one in the evening (commencing at 19:35) and one in the early morning (concluding at 07:30) to eliminate solar loading and ensure a sufficient temperature differential was maintained between internal and external environments.
- Operational Constraints: Standard protocols typically recommend a vacant environment where heating services can be deactivated two hours prior to inspection to prevent thermal anomalies. As The Marlowes remained an active shopping centre, this was not possible. Our team had to navigate an environment where internal services were running and automatic doors were recently cycling, creating transient temperature fluctuations.
- Variable Mitigation: To account for these active conditions, our thermographer applied specialist interpretation to distinguish between genuine fabric defects and “active” false positives. This included filtering out residual heat from lighting and accounting for “cold sky” radiation affecting the complex glazed atria.
Key Findings: Visualising the Invisible
The survey provided UEC Energy with a comprehensive condition assessment of the building envelope. By analysing thermal anomalies, we were able to isolate actionable defects:
- Targeted Air Leakage: We identified extensive heat loss around the perimeter of openable windows and external doors. Crucially, the thermal signatures confirmed the issue lay with degraded seals rather than the glazing units themselves—identifying a high-impact, lower-cost repair.
- Critical Thermal Bridging: The imaging revealed significant heat flux radiating from corner junctions, intermediate floor zones, and steel structural beams.
- Insulation Continuity: Cold spots detected on external elevations indicated potential voids or settling within the wall insulation, warranting further borescope investigation.
- Hidden Water Ingress: Beyond energy performance, the survey highlighted thermal patterns on the roof above the management suite consistent with trapped moisture. This early detection identified a critical maintenance priority, alerting the client to potential structural risks before visible interior damage occurred.
The Outcome
By identifying these specific defects, Building Energy Experts provided a prioritised schedule of fabric interventions for The Marlowes Shopping Centre.
This data-driven approach allows the client to direct their maintenance budget where it will have the most significant impact on energy efficiency and building health—in this case toward specific draught-proofing and insulation improvements—directly supporting the uplift to an EPC B rating.
Surveying an active shopping centre is logistically complex, but Building Energy Experts handled it with precision. Their report cut through the environmental variables to provide a clear distinction between maintenance quick-wins, like resealing doors, and the capital investment needed for insulation. It provided the exact technical evidence required to inform our roadmap to an EPC B rating and justify the retrofit budget.
Philip Emsley, UEC Energy
Data-Driven Decarbonisation
Invisible defects like heat loss and air leakage are often the missing link between your current performance and your target EPC rating. We provide the technical insight required to identify these gaps in complex commercial assets.
Whether you manage a commercial complex, a historic site, or a housing portfolio, we can help you identify the right decarbonisation strategy for your building.
