By Peter Aramayo, Commercial Director
As a country, we’re fortunate to have a great number of beautiful and historic buildings on our streets. However, we have a duty to ensure that these structures remain standing for future generations to enjoy, maintaining their functionality and preserving our country’s heritage. Undertaking repair or improvement works, often centuries after they were originally built, can be a challenge - this is where Civil Engineering and façade retention comes into play.
Often used on listed buildings, façade retention involves the perimeter or façade of the building being temporarily supported, while the layout of the structure behind is updated, or changed entirely to better suit modern-day needs.
Unsurprisingly, façade retention schemes can be hugely complex, requiring careful consideration of where the existing structure, the temporary steelwork and the new, permanent works all meet. Ensuring that all loads and deflections are accounted for in the engineered design, that there are no clashes between the various project phases and the structural integrity of the façade is monitored and protected throughout construction can present contractors and engineers with a major headache.
Here, BIM and digital engineering can have a big role to play. Attempting to design a façade retention scheme using 2D methods can be a time-consuming process. Adopting a BIM workflow allows the temporary works design to be fully incorporated within the projects Revit model, ensuring full co-ordination with the existing façade. Repetitive tasks can be automated in conjunction with an improved clash detection process. This way of working assists Engineers in determining the most efficient system design, reducing the weight of supporting steelwork, resulting in project cost and programme savings.
With the correct 3D scanning equipment, digital engineering teams can also take a detailed scan of the whole existing building and façade, input this into their chosen BIM software and then design the temporary propping works around the 3D building model, ensuring high levels of accuracy and detail.
The benefits of BIM can be especially felt on city centre projects, where densely populated and busy urban locations can provide an added challenge. Here, the 3D environment allows teams to model and consider not only the individual building in question, but also the context of the wider site, including roads, other buildings and live infrastructure assets. This allows for improved visibility of the whole location and context of the project, helping to more efficiently identify any potential design or construction challenges (e.g. existing structure clashes) or areas of concern, prior to getting on to site.
While some people may assume that the temporary works aspect of a project is completed once the building façade is successfully propped, this is not necessarily the case. With the retention framework representing such a significant part of the project’s enabling works, it’s vital to ensure that the propping system continues to protect and preserve the structural integrity of the building and façade - both from a health and safety and a heritage perspective. With such projects involving the partial or total demolition of the remaining structure behind the retained façade and the commencement of heavy construction works, intense vibrations are largely unavoidable. However, if not correctly managed, the effect of these vibrations on the façade’s structural integrity could be disastrous.
To proactively avoid such a situation, structural monitoring solutions can be incredibly useful and valuable on propping projects. This technology will monitor a structure’s behaviour and performance in real time, identifying any changes such as load, rotation, displacement, strain, fatigue, vibration and deflection. The project’s Engineering team have direct access to this data, giving them the ability to react to any potential structural issues quickly, safely and efficiently.
We have extensive experience in designing, supplying and installing the necessary steel temporary propping systems required on façade retention projects. With a wide range of temporary propping systems available to hire in conjunction with our engineering, digital and structural monitoring capabilities we can provide a bespoke solution to meet your individual project requirements, assuring that your façade is in safe hands.