An engineer for all seasons

Monika Rogers, senior structural engineer at Perega discusses engineers' responses to that Great British topic - the weather.

Erratic weather is increasingly becoming the norm, as climate change continues to upset the meteorological balance. In the UK alone, we’ve seen a significant increase in rainfall and, consequently, flooding. Only recently, the country endured a torrential downpour, which amounted to half a month’s worth of rain in a mere 24 hours. 

It’s all having a profound impact on society and is changing the way we plan, design, and build in urban and rural settings, to futureproof our assets against increasingly hostile weather conditions. 

Of course, civil and structural engineers have a significant role to play in the delivery of buildings and infrastructure specifically developed to handle hotter, drier summers and cooler, wetter winters. 

Not only that, the profession is simultaneously committed to the massive task of reducing the construction sector’s substantial carbon footprint. Both The Institution of Structural Engineering and The Institution of Civil Engineers have made it very clear regarding the responsibility we engineers have to leave the world in a better place than we found it. 

So you see, it's very much a combined case of adaptation and mitigation. But what’s currently being done nationwide to realise a climate-capable built environment? Here, I'd like to take the opportunity to explore some of the things we're doing to achieve this goal. 

After the Flood

Flooding can have catastrophic consequences, with population displacement and service disruption causing considerable socioeconomic havoc, and it's becoming a more frequent problem in the UK. It’s predicted that, by 2050, one in six UK homes could be at risk, leading to greater investment in robust defence systems.

The recently greenlit South-East Cardiff flood defence scheme is a fine example of the measures currently being taken. Set to safeguard almost 2,000 properties across the city against the onslaught of extreme weather, it also presents an opportunity for the civil engineering community to showcase its skills in this area, assisting with the construction of 150,000 tonnes of rock barrier, sheet piling, and rock protection for the Lamby Way Bridge. 

The significance of large-scale projects like this is undeniable, yet there are smaller-scale solutions that also pack a punch when it comes to flood prevention. Take Sustainable Urban Drainage Systems (SuDs). Mandatory in all new developments since the start of 2023, SuDs provide some protection, helping to manage peak runoff after rainfall to prevent flooding, mimicking natural drainage with geocellular tanks, and controlling surface water at the source. 

SuDs can also play an important role in the drive towards net zero, converting run-off grey water into a useful and sustainable resource, providing hydration for municipal parks, agriculture, and even increasingly popular green roof systems, helping to boost the natural environment, and lower emissions. 

Play in the sunshine

Global warming presents yet another challenge for engineers with overheating in urban areas increasingly becoming a concern, creating a 'heat island effect', which can have a significant impact on public health and wellbeing. 

Of course, advanced HVAC systems exist, however, they come at a substantial carbon cost, prompting specifiers to look at ways in which to cool buildings by enhancing their structures, particularly the façade. 

On the most basic level, ventilated facades provide the best solution. Curbing heat absorption during high temperatures, redirecting solar radiation into shaded areas, creating a cooling 'air wash’ through the intermediate cavity, between the exterior glass and the facade.

Looking beyond their core function, ventilated façades have evolved into high-tech, high-performance systems that deliver a variety of benefits. This includes window-specific shading systems, such as solar control glass incorporated into glazed facades, or external shadings, including canopies and awning roofs. These enhancements achieve cooler interiors during prolonged hot and sunny spells, whilst reducing energy bills and emissions. 

Fit for the Future

Retrofitting presents a significant challenge here, especially when it comes to adapting heritage stock, with many historic assets out of compliance with current energy standards and green regulations. 

However, this is where engineers can play a greater role, providing recommendations and consultancy to help squeeze the most sustainability out of the building’s existing fabric, whilst maintaining structural integrity.

It’s well known that repurposing existing frames if they’re in a good state of repair, is far more ecologically friendly than demolition and reconstruction. From here, these existing structures can then be futureproofed with the latest features, fixtures, and fittings to make them resilient to an era of erratic climatic fluctuation. 

Fortunately, the Government is a vocal advocate of retrofitting and there’s little doubt that it will become the default, alternative approach to simply demolishing perfectly good properties. 

So, with the rising prominence of climate adaptation and retrofitting strategies, structural and civil engineers emerge as vital catalysts, poised to offer expertise for the creation of sustainable infrastructure.