The Almeida Street project involved the re-development of a former Royal Mail sorting office in Islington to create a prestigious mixed-used scheme comprising commercial office space, retail, residential apartments and serviced apartments, which are operated in a hotel-style short-term lettings basis.

The scheme was divided into two blocks and the developer had struggled to gain a fire engineering approach that would address the unique challenges of the original building layout and the interaction of its varied new uses. As a result, FDS consult was appointed to replace the previous fire design consultants and apply the company’s creative, strategic fire design expertise to the project in order to address the scheme’s challenges and gain building regulations approvals.

Block B includes a large retail complex, leisure centre and gym, commercial office space and residential apartments.
The retail complex is situated in a central area that occupies the basement levels, the ground floor and the first floor, with a central staircase rising up the full height of all these storeys forming an atrium. This central staircase/atrium element of the architectural design in the shopping complex meant that there was an issue with the speed at which smoke could rise up through the building in the event of a fire and this was exacerbated by the small (3m) floor to ceiling heights which meant that there was almost no smoke reservoir. What’s more, there were very limited opportunities for installing smoke venting solutions in the external walls to address the problem. FDS Consult’s expert team responded to these issues by:

• Sub-dividing the retail areas into zones using smoke curtains, which reduced travel distances, improved escape routes and reduced the smoke venting requirements
• Using CFD (Computational Fluid Dynamics) modelling to justify the reduction of smoke venting arrangements to automatically opening windows at high level
• Introducing fan-assisted shafts to protect fire service access at basement levels
• Devising a zoned evacuation strategy to improve business continuity

In the residential areas of Block B the main challenge was justifying extended travel distances and FDS Consult’s experience enabled the team to achieve this by introducing fan-assisted smoke shafts.
The fire engineering challenges presented by the residential accommodation in Block A were more complex, largely due to the fact that there was a mix of residential apartments, serviced apartments and commercial offices sharing the same staircases. Block A comprises a basement car park with ground floor and a further six storeys of accommodation and it has an unconventional rectangular ‘doughnut’ shape with a staircase on each corner. As residents from the serviced apartments were likely to be unfamiliar with their surroundings the risk factors were greater for these occupants but the accommodation was mixed on each floor.

FDS Consult’s creative approach enabled the team to:

• Carry out a complete risk assessment
• Introduce fan-assisted venting to manage smoke levels
• Install a fire detector above the front door of the serviced apartments which was accessible without entering the apartment and linked to the development’s building management systems. This meant that any fire in the serviced apartments could be detected early and centrally, allowing the building management team to evacuate occupants from the serviced apartments and commercial offices, fulfilling the landlord’s duty of care
• Justify extended travel distances thanks to the two-way direction of escape provided by the staircases on each corner, the smoke venting arrangements and the use of CFD modelling to demonstrate safe evacuation times FDS Consult’s involvement with the Almeida Street project not only delivered a practical solution that worked with the building’s original design but it also provided substantial value engineered cost savings.