Trencherfield Mill.
Critical systems,
retrofitted in occupation.
A heritage-listed mixed-use mill — residential apartments above commercial tenants — recategorised under the Building Safety Act as a Higher-Risk Building. Multiple life-safety and resilience systems redesigned, specified and delivered without taking the building out of service.
A heritage mill,
a modern compliance
obligation.
Trencherfield Mill is a heritage-listed brick mill on the Leeds–Liverpool canal, converted to mixed residential apartments and commercial occupation. Beautiful, hard to alter, fully tenanted — and, since the Building Safety Act, classified as a Higher-Risk Building.
[Directors to rewrite naturally. The brief over the last few years: survey the building's M&E systems, identify the compliance and life-safety risks against the new HRB regime, and design realistic, specifiable solutions that could be procured and delivered without disrupting the residential or commercial tenants in occupation.]
[Continuation — that constraint shaped every decision. Replacement equipment had to fit through existing risers and corridors. Cause-and-effect testing had to happen in temporary configurations. Tenants couldn't lose power, smoke ventilation, emergency lighting or hot water for more than a few hours at a time. This is engineering that doesn't show up in glossy renders — but it's where Prana's experience earns its keep.]
Four critical systems,
redesigned
and replaced.
Each system surveyed, root-cause assessed against current compliance, fully redesigned, specified into tender, and monitored through installation and commissioning.
Emergency Lighting — Building-Wide Replacement
Full redesign and specification of the emergency lighting system across the entire building. New self-contained luminaires, escape route compliance to current standards, and a coordinated approach to existing fabric that allowed installation to proceed in a tenanted heritage interior.
Back-Up Diesel Generator — Replacement Genset
The original generator was dilapidated and no longer reliable for life-safety duty. Prana specified a replacement genset, sized for the building's life-safety load demand and integrated with the existing infrastructure. Designed to commission alongside the existing unit before changeover, minimising downtime.
Life-Safety Switchgear & LV Infrastructure
The generator replacement triggered a wider review of the life-safety switchboard and LV distribution. Prana designed the switchgear upgrades, cause-and-effect logic, and the LV infrastructure changes required to make the new genset operate correctly under fault conditions and emergency demand.
Smoke Ventilation — Mechanical Repairs & Replacement
Specification of replacement fans, ductwork repair and motorised damper replacement for the existing smoke ventilation system. Each component selected to match the original system intent while meeting current standards — and to allow phased replacement without taking the smoke vent out of service for the residential occupants above.
BSA experience,
earned on a real building.
The Building Safety Act is new to the industry. Most consultancies are still working out what compliance looks like in practice. Trencherfield Mill is one of the buildings where we worked it out.
[Directors to rewrite naturally. The combination — heritage fabric, HRB classification, mixed occupation, in-use replacement — covers most of the difficult moves an MEP consultancy will face under the new regime. Prana now applies that experience to new-build HRBs (currently advancing Lissadel Street through BSA Gateway 2) and to other existing buildings being recategorised.]
[Continuation — what this means for clients with HRB stock or HRB new-builds: you're not paying us to learn the BSA on your project. We've already done that.]