By: Iris Chang, Associate

Ancoats Mobility Hub (the Hub) is an innovative project that supports the future development of Poland Street in the Ancoats area of Manchester. It is a striking building that includes a multi-storey car park with commercial units, a cycle store and associated changing facilities. Its façade has an expansive green wall and landscaping that complement the adjacent Ancoats Green.

With an approximate footprint of 18,300 sq ft and a height of 25m to the topmost occupied storey, the Hub offers just over 400 car parking spaces.

Key features: (as noted by Manchester City Council)

• 14,000 sq ft of new public spaces and walking routes connected to Ancoats Green
• 4,300 sq ft of green wall for a greener environment
• 406 car parking spaces for residents and visitors
• 400 rooftop solar panels for renewable energy
• 150 secure bike parking spaces with changing facilities
• 102 electric vehicle charging points, with room for more
• 30 spaces for car club/car share schemes

DFC became involved with the scheme during RIBA Stage 3 of the works and provided our fire engineering services through to project completion.

As a steel frame structure with composite slabs, the building was designed as an open-sided car park. Permanent ventilation was provided across the car parking storeys via openings around the building’s exterior. These well-ventilated conditions meant that the steel frame did not require additional fire protection, in line with the recommendations of the Approved Document B (ADB), which provides guidance on fire safety.

The height of the building and the proposed use of a green wall in the project presented a challenge that required thoughtful consideration of the adequacy of applying ADB guidance without further scrutiny. Furthermore, with ongoing industry concerns about the severity of fires involving electric vehicles, it was critical to evaluate how these incidents fit within existing safety regulations. Recent incidents of car park fires suggest that fire can spread significantly in these environments.

We recognised that adopting ADB guidance directly might not be appropriate for this project.

DFC was instructed by B&K to carry out a comprehensive fire resistance review to determine the optimal fire rating for the Hub. The assessment considered existing car park fire tests, current statistics on the commonality of electric vehicles currently in the UK, case studies from previous car park fires, the response of a steel frame structure in a fire scenario and how the green wall design impacts fire safety.

A 60-minute fire rating was recommended for the building as the appropriate fire rating for this open-sided car park to meet Part B of the regulations. DFC then consulted with Building Control to finalise this approach and the proposed use of the green wall as part of the building design.

Developing this assessment was very interesting and represented one of the most noteworthy challenges for this project from a fire strategy perspective.

During the construction phase, we continued to provide fire strategy advice to our client B&K. Our team encountered many interesting and innovative challenges throughout the project that were not expected compared to many other building types. For instance, we addressed the anticipated deflections within car park slabs against tolerances for movement in firestopping details, designing door closers to prevent fire doors from being pulled open in an external environment, and ensured that steel elements passing through fire-resistant walls were adequately protected.

This was my first experience in fire safety engineering for car park design and I had lots of support and insights from my colleagues, including Adam, Akshay, Max, Neal, and Stephen at various stages. The collaborative environment at DFC really promotes a culture of knowledge sharing and continuous learning, which is so important to our goal of attracting and nurturing talented professionals who will help our team thrive.