Canon and Priory House

Façade cleaning using DOFF technology

Cannon House is a landmark 358,733 sq ft office complex located at Two Colmore Square in Birmingham. Spanning seven storeys with additional basement parking, the building occupies a prime city centre position. Originally constructed between 1959 and 1962 with a Portland limestone façade, the property has undergone several major upgrades—most recently in 2024–25 as part of a future-focused refurbishment.

The goal of the works was not just visual restoration, but long-term sustainability. The building is targeting high-performance benchmarks, including WiredScore Platinum, Fitwel 2-Star and EPC A certification. William Parratt Masonry Ltd was appointed as a Stonehealth Rosette Contractor to deliver sensitive façade cleaning using DOFF technology.

This project presented a number of logistical and operational hurdles that required careful planning and expert delivery:

• Scale & Access: With vast elevations and no scaffolding due to cost and design complications (exceeding hundreds of thousands), rope access was the only viable solution.
• City Centre Location: The property’s central Birmingham setting meant high foot traffic, requiring strict safety protocols to protect the public.
• Façade Sensitivity: The natural Portland stone required a method that would clean effectively without damaging the substrate.
• H&S & Coordination: Operating at height demanded robust supervision and programming to ensure compliance with health and safety regulations.
• Client Expectations: The works needed to be delivered on time and to budget without compromising quality.

Rope access abseil teams were used throughout, with clear planning and supervision of operations. Public safety was prioritised with overhead protection zones and fully managed access routes.

The DOFF system was instrumental to the project’s success. It delivers superheated water at temperatures up to 150°C, providing a powerful yet gentle cleaning method for stone and masonry. With its low water flow and precise control, the DOFF Integra 110v machines were ideal for use in an urban environment—reducing water run-off and preventing damage to sensitive surfaces.

Service

Stone Cleaning

Location

Birmingham Colmore Circus

Completed

2024