Big Foot Systems Rises to the Challenge


ProjectShopping Centre, Nottingham
Roof FinishWarm Roof, Single Ply
SupportedAHUs & Chillers
Big FootHD Beams, Custom Steels and HD Frames

Big Foot Systems has supplied HD Beams, Custom Steels and Custom HD Frames as part of a £40 million redevelopment of a shopping centre. Originally constructed in the late 1960s, the centre required a refurbishment to be able to compete with other local retail complexes, including new HVAC plant.



With retail space at a premium new locations were needed for the chiller plant with the rooftop an obvious choice. Meanwhile, the existing AHUs also needed to be replaced and relocated. The original AHUs were located on plinths that were constructed when the shopping centre was initially built, but since the new AHUs were larger, the existing plinths could not be utilised without structural alteration and so an alternative solution needed to be found.

With the new rooftop location for plant posing a few issues, Big Foot Technical worked closely with the contractors to design a suitable solution. The 1960s roof had not been designed to support plant and so the permissive loads on the roof were limited to a UDL of less than 4kN/m². Another challenge was that the roof is due to be re-roofed at a future date, therefore any frame supplied had to provide adequate stability and clearance for re-roofing.

A custom design was therefore required for the project with Big Foot Technical’s highly skilled engineers, using industry-leading software, including 3D CAD and ANSYS FEA, to create a

solution that would support the chillers and AHUs, provide the required clearance and could maintain an imposed UDL of less than 4kN/m2.

“This was a complex project due to the weak roof. Initially it was thought that the plant loads would need to be taken back to the main structural beams but, working with the contractors, Big Foot Technical was able to design a solution that could be supported by the roof whilst being secure, below the UDL and at a lower cost than initial options” explains Sam Birch, Big Foot Systems. “The client is very pleased with the end result and we are delighted to have been able to provide a high quality, cost effective solution.”

HD Custom Frames are project specific, non-penetrative support frames for large, heavy, irregular shaped or unevenly loaded plant. With the aid of technical surveyors, a highly skilled engineering team and use of engineering tools such as ANSYS (FEA/CFD) etc. Big Foot Systems can design and manufacture complete one-off solutions.


Solutions include frames similar to a standard LD product but utilising larger and longer sectional bars; a custom arrangement of HD Cubes or HD Beams; or, for more complex applications, a frame can be designed and fabricated specifically for the project requirements. At this level, complex engineering tools for non-standard components can be explored.

HD Beams are a non-penetrative support solution for chillers, AHUs, packaged plant, generators, pipes and steels. They are a robust but flexible solution where space may be limited, or there is a requirement to position directly over existing structural roof beams, and weight is evenly distributed across the specified quantity of HD Beams. They are also height adjustable to maintain a level system on roof falls up to 5 degrees.

Offering specifiers a comprehensive range of freestanding systems, Big Foot’s products are designed and manufactured by the company for a wide variety of applications, including HVAC, louvre and safe access equipment. The product portfolio provides simple, safe and secure, non-penetrative, roof support systems negating a need for time consuming and costly penetrations through the roof.

Big Foot Systems’ products and systems are quick and easy to install ensuring project cost and time clarity, thus reducing the need for complex, time-consuming and expensive detailing. Offering improved roof aesthetics, Big Foot Systems provides engineered solutions that are innovative in design, robust and repeatable. Big Foot combines market leading products and services, which include system design and on-site support. Available to install in all weathers utilising familiar componentry, all systems are designed with safety, security and simplicity in mind. Finally Big Foot Systems offers short manufacture and delivery lead times to help a project meet its schedule and stay within budget.