How engineering creativity can deliver commercial viability
Fifty5ive Queen Street is a stunning 18-story tower block located on the Manchester Salford border. Comprised of 220 one-, two- and three-bedroom apartments, the hyper-modern development offers a vibrant and fast-paced community for those that want a life that goes beyond the ordinary.
With apartments for every need, residents will enjoy a suite of communal offerings such as a community workspace, a gymnasium, a cinema room and a terrace garden.
Working for our client Salboy, our well-considered efficient design laid the foundations for a development that could push the envelope while remaining commercially viable.
The Fifity5ive Queen Street project specifics
Fifty5ive Queen Street began life as two separate designs across two adjacent plots. In its final incarnation, the development was made up of three linked buildings, delivering a premier residential complex offering some of the most sought-after apartment living in the city.
Like any large residential development, financial viability was a key deliverable. As engineers, our task was to look at the architectural designs and deliver a scheme rich with quality, panache and innovation all while pursuing a positive commercial outcome.
In this case study, we’ll take you through the steps we took to deliver on this task, looking specifically at how our interventions delivered great design features that enhanced the commercial viability of the project.
More units = more commercial value
One of the defining features of the Fifty5ive development is that the building cantilevers out 3 metres from the ground floor. Achieved using walking walls and columns, this eye-catching feature offered more than just aesthetic value.
A relatively unique technique across Manchester’s skyline, the walking wall and column method enabled Salboy to place two extra units from the first floor up. Across an 18-storey development, that equated to 36 extra units and significantly enhanced post-project revenue.
The subtle engineering know-how employed to deliver this extra floor space went a long way towards maximising the development opportunity of the site.
Focusing on a commercially viable framing solution
With any large development, 20-30% of a building’s construction value is found in the frame, so reducing material usage there can yield large savings. renaissance is an engineering consultancy driven by efficiency in design and delivery, so we’re constantly tuned into the ways we can optimise a project.
At Fifty5ive Queen Street, we went through an extensive exercise in optimising the column grid. Ultimately, the plans we delivered allowed us to reduce the floor plate thickness and reinforcement quantities needed for the structure, yielding significant material usage reductions and a healthy cost saving. When benchmarked against designs by other firms, these materials savings were up to 20%.
The elegant engineering gymnastics we employed not only generated significant value for our client but cut out a huge portion of embodied carbon from the footprint of the project.
Navigating challenging site conditions
The site itself was situated rather awkwardly. With a dual carriageway, listed buildings and basement structures all adjacent to the site, we had to employ innovative temporary works to protect these facilities during construction.
Because three sides of the building were street-facing, we were posed with a challenge from a foundation design perspective. To manage this constraint, the foundations of the building were set at shallow depths to reduce the requirement for temporary works and to de-risk the construction process on site.
Achieving the mega columns
A stunning aesthetic feature of the structure is the mega columns located externally at the ground floor. A conceptual baby of the architect, the mega columns play a big role in the visual grandeur of the building. These columns connect the ground with the 3-metre projection that occurs at the first-floor level and are presented as you approach the building, grounding the structure
In the construction of these mega columns, we used ground granulated blast furnace slag (GGBS). There are many benefits to working with GGBS, chief among them being its low carbon footprint and its ability to manage the concrete’s heat gain.
Because the columns are such an aesthetically important element of the structure, every detail needed to be correct. The combination of considered reinforcement detailing with the use of GGBS ensured the cast surface of the columns was smooth and not fissured.
What the client had to say
“The project at Fifty5ive Queen Street perfectly encapsulates what’s great about inner city living. Set in a prime location and offering top-of-the-line facilities, the complex delivers something special for those wanting to be close to the action.
“Through their design focus and engineering know-how, Renaissance enabled us to deliver all the extra special details we wanted for the development, while also maintaining a viable commercial edge.” – Nick Russell: Salboy