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Orion Fire has supported the Bollo Lane regeneration in Acton since RIBA Stage 2 , providing fire engineering consultancy across Blocks A/B and J/K. This major mixed-use scheme brings together purpose-built student accommodation, affordable homes and commercial space, and has now achieved Gateway 2 approval from the Building Safety Regulator through two independent applications – a significant milestone as the development moves towards construction.

• Blocks A/B, the taller elements of the development, rise to 21 storeys, delivering 429 student rooms alongside commercial space at ground and first floor.
• Blocks J/K will rise to 12 storeys, delivering 95 new homes and five commercial spaces.

While the buildings differ considerably in scale and use, the challenge was similar for both: developing robust fire safety strategies that support the architectural design while providing practical solutions for residents, visitors and the fire and rescue service.

Designing fire safety around the building

Fire engineering at Bollo Lane has been integrated into the design rather than treated as a standalone exercise.

Both buildings combine sprinkler protection, fire-resisting construction, protected escape routes, evacuation lifts and mechanical smoke control. Dedicated firefighting shafts provide protected routes through the buildings for fire crews, with wet risers in the taller Block AB and dry risers within Block JK.

Inclusive evacuation has also played an important role. Evacuation lifts and protected waiting areas are incorporated into the residential cores, providing an alternative to relying solely on stairs for people who may need assistance leaving the building. Separate provisions have also been developed for the commercial areas, with flexible arrangements to suit all future tenants.

Testing smoke movement before construction

One of the most interesting aspects of Orion’s work at Bollo Lane has been the extensive use of Computational Fluid Dynamics (CFD) to test the smoke-control designs. CFD allows engineers to simulate how smoke and heat are likely to move through a building during a fire. At Bollo Lane, the modelling examined conditions within corridors, evacuation lift lobbies and stairs during both evacuation and subsequent firefighting operations.

Across the two buildings, 17 separate fire scenarios were assessed, including fires at different levels and locations within the buildings. For Block AB, the modelling went one step further by considering a particularly demanding scenario in which the sprinkler system was assumed to fail and the fire developed to a significantly larger scale (2.5MW). Even under these conditions, the firefighting stair remained free from smoke throughout the simulation.

The results provide a useful way of translating complex fire engineering into something more tangible.

Fire engineering is often about the details

Some of the most interesting complexities at Bollo Lane were not necessarily the largest.

In Block AB, the relationship between cooking facilities and sleeping areas within student studios was carefully considered. Hobs were positioned away from escape routes wherever practicable, with automatic hob cut-off devices incorporated into selected layouts where additional protection was appropriate.

Both buildings also feature landscaped rooftop areas. Rather than treating planting simply as an architectural feature, the fire strategies consider the construction of planters, growing-medium depth, irrigation and ongoing maintenance as part of the overall approach to fire safety.

Block JK presented another unusual design feature in the form of an open-air link bridge connecting areas of the first-floor commercial accommodation. Its open construction and relatively low-level, transient use allowed its fire performance to be considered specifically rather than applying a conventional internal-floor solution.

Collaboration through Gateway 2

Fire strategies for complex higher-risk buildings continue to develop as architectural, structural and building services designs become more detailed.

At Bollo Lane, this has involved ongoing coordination with the wider project team and responding to matters raised through the Building Safety Regulator review process. The work has included refinement of apartment layouts, smoke-control arrangements, firefighting facilities and means of escape as the design progressed.

The result is a fire engineering approach that combines established guidance with detailed analysis where the building calls for something more specific.

For Orion, the project demonstrates the value of bringing fire engineering into the design process early and carrying it through the technical stages: understanding the architecture, testing the challenging areas and developing solutions that work in the finished building.

From the Orion Project Team:

“It’s been a challenging but rewarding journey to get to this point, and we’re looking forward to seeing the designs we’ve worked on take shape on site as we continue to support the project through RIBA Stage 5.” – Oskar Dzielak, Director