:quality(85))
The judges commended Cathedral Hill Industrial Estate as a standout example of regeneration delivering value for both businesses and the environment. Through a deep retrofit, the development not only achieved operational net zero but also drove a remarkable 220% increase in rental value.
The £10m refurbishment of 13 units combined building fabric upgrades and service improvements, including the installation of heat pumps and battery storage. Enhanced insulation between offices and warehouses improved thermal comfort, environmental control, and acoustic performance. A sustainable sourcing strategy prioritized reuse—stone masonry waste was repurposed for gabion walls, and existing concrete floors were polished or screeded.
A full services audit led to the replacement of nearly all gas heating systems with air source heat pumps, point-of-use water heaters, and panel heaters. Tesla Powerwall batteries store surplus solar PV energy, ensuring the development remains net zero in operation. The project also achieved an impressive upfront carbon footprint of just 281 kgCO₂/m² GIA, far below the Net Zero Carbon Buildings Standard 2025 targets.
To ensure long-term performance, a two-year soft landings period is in place, alongside live energy monitoring and an app-based fault reporting system for tenants. Post Occupancy Evaluation includes operational performance testing, occupant feedback, and facilities management insights to continuously optimize efficiency.
A focus on health and wellbeing shaped the design, with an Indoor Air Quality Plan addressing potential risks early in development. 100% openable top and side-hung windows enable natural purge ventilation, eliminating the need for mechanical cooling, as confirmed by Thermal Comfort modelling. Daylighting is maximized through mezzanine glazing and polycarbonate roof lighting.
The results speak for themselves—once under-occupied and 33% below Guildford’s average rental values, Cathedral Hill is now a high-demand site, with rental values 220% higher and a waiting list of tenants.