Paul McDevitt, Managing Director of TÜV SÜD Building Advisory Service, a data management and analytics business, which ensures that building owners, managers and occupiers can access the information they need to make fully informed decisions.

Authorities across the world are now beginning to regulate on the scope and intervals for façade inspection. Insurance will also require building owners to show that the relevant maintenance needs have been met. Failure to maintain the building façade properly may result in increased insurance premiums, difficulty in obtaining insurance renewals, or the termination of insurance cover. In the UK, the imminent Building Safety Bill and the new Building Safety Regulator will also require compliance, through the annual production of the Safety Case. This will directly impact on the owners, and managers if high rise residential buildings (18m or six storeys).  It is therefore vital that those responsible for a building’s maintenance and upkeep can demonstrate to insurers and regulators that all reasonable steps have been taken by implementing appropriate risk management procedures. This should include periodic façade inspection.

Periodic façade inspection will help to detect potential issues and underlying problems with a facade early on, such as cracks, corrosion and flaking. It will also help to identify the level of defect deterioration and minimise the risk of any compromised facades exposing safety risks.

Façade inspection is therefore an integral part of building survey as it helps to verify the integrity of the building structure and ensures safety. Not only is façade inspection vital to support building operators and owners of large high-rise buildings, it can also be used to help construction companies ensure the quality of façades and monitor the progress and quality of their construction projects.

The degree of façade inspection and maintenance that is required will depend on the materials used and its intended life. In the UK, the Building Research Establishment (BRE) divides the necessary frequency of inspection into three categories.

• Routine – continuous regular observations that should be undertaken by the user as part of the occupancy of the building.
• General – visual inspections of main elements.
• Detailed – a full inspection of the façade by a suitably qualified person.

However, conventional façade inspection usually requires roof access and involves the use of gondolas, all of which is time, labour and cost intensive. It is also highly disruptive for occupants, and dangerous for inspectors due to the difficulty of accessing high-rise buildings.

As economical and effective façade maintenance is therefore now a prime consideration within the overall building design process, existing façade maintenance systems cannot be diverted to dedicate time to more detailed survey work that could be easily completed by drones. Likewise, employers must ensure, so far as is reasonably practicable, the health, safety and welfare of their employees and to ensure that those affected by their activities are not exposed to risk. This includes potential hazards such as falling from height or operatives becoming trapped in the manned platforms. Using drones takes way these additional risks for the detailed surveying of facades.

Smart inspection

Smart façade inspection using digital twin technology can automate and improve façade inspection quality, as well as save costs and minimise safety risks. This innovative approach to façade inspection uses automated drones and artificial intelligence (AI) to check for deteriorating materials and underlying problems with building façades. As it is equipped with a smart piloting system, the drone ensures both operational safety and high-quality inspection. High-resolution visual and thermal cameras can accurately scan the exterior of buildings, with thermal cameras being particularly effective for the detection of any hidden defects, capturing potential facade failure points.

An advanced AI model will also ensure that compliant inspection reports, which meet the highest industry standards, are delivered. This is achieved by using a drone to capture images along the façade of the building. AI can then be used to assist human inspectors with data analysis. Raw data, collected by the drone, is fed into the AI platform, so that the algorithms can be used to maintain privacy by detecting and masking people that have inadvertently been photographed by the drone. At the same time, they identify façade defects, classifying them by type (cracks, decolouration, corrosion, sealant deterioration etc) and severity, as well as give recommendations for repair. As AI is not infallible, it is vital that a human inspector reviews the results and uses engineering judgement, giving feedback that can be used to continually improve the AI algorithm.

This means that façade inspection can be conducted in a fraction of the time and cost, as compared to the traditional methods of inspection. The resulting 3D model of the building façade is also helpful in better understanding the building’s structure and will also automatically update any detected defects. Inspection reports are also able to make use of an intuitive 3D model, so that the state of the façade can be visualised, and any necessary repairs tracked and managed. This is because the façade inspection software constructs a 3D model of the building façade, which helps to better understand the building structure and automatically locate and detect defects on the building. As repairs and follow-ups can be seamlessly managed through the drone platform, along the lifecycle of a building, efficiency is improved, and costs saved.