Changing weather across the globe is altering how engineers design buildings. 

Climate change has far-reaching effects on all aspects of our daily lives. While warming and rising sea levels are the most talked about side effects, extreme weather conditions resulting from the shift also has an effect on the way engineers design buildings. 

Civil and structural engineers that spend their days designing structures and buildings don't just take into account normal loads like people or furniture into their design, rather they also take into account things like snow, ice, wind, and, in rare cases rain loads.

These different load conditions brought about by an area's local weather conditions affect various aspects of a building's design, from the support structure to the materials used in construction. 

Those loads we just mentioned are purely structural, but changes in temperatures can also lead to increased corrosion, decreased strength, and all sorts of other material degradation to the existing structures.

As climate change takes place in many regions, the initial assumptions and design traits that engineers created the structures around are becoming invalid, and the structures cannot handle this. 

The impact of changing weather on building design

While there is still a debate around what is causing the climate change, there is no doubt that global temperatures are rising. Between 2002 and 2008, temperatures rose .8 degrees Celsius.

On average, according to Climate.org, the world temperature rises about 0.36 ºF (0.2 ºC) every decade. That may not sound like a lot, but it is estimated that a sustained global thermal rise of 2.7ºF (1.5ºC) is enough to put millions of people at risk of famine, heat waves, and poverty. 

All this change in temperature is already disrupting the weather patterns in various regions across the world. Certain areas are getting higher amounts of precipitation, which in reference to structure design, can increase erosion and increase the frequency and magnitude of expansion in different types of soils, like expansive clays. 

Certain areas are getting longer, more frequent heat waves, which is decreasing the relative thermal capability of insulation in buildings, meaning air conditioning systems must run for longer. 

A lot of building design today in a category you likely know of, referred to as 'green building' or green construction, green architecture, etc. This type of construction addresses many of the concerns related to climate and weather change.

Notably, though, much of green building practices are aimed at mitigating the effects that the construction industry and buildings themselves have on furthering climate change.

This means using things like well-sourced materials, utilising passive ventilation, and laying out the structure in a way that the environmental conditions can aid in the heating and cooling of the internal structure.

Thermal effects

System designs like passive cooling and heating will help mitigate many of the thermal effects that climate change is bringing, but it will most likely not suffice.  

In order to fully grasp what is changing about building design, it is best to look at the extremes. The areas of the world where climate change is forcing the hand of local engineers and designers the most. It is these areas where engineering for climate change is not just a preference or a choice, it is a necessity of the design process. 

In New Orleans for example, most of the city sits below sea level. For years the city was protected by levees and dams that held the rising seas back. However, Hurricane Katrina in 2005 knocked out many of the city's barriers. Engineers have had to proactively consider what the future of the city may hold. 

Example of a large structure built with a raised foundation. Source: Shustov/Wikimedia

The city is highly vulnerable to strong storms, even more so in the age of far more extreme storms brought about by rising temperatures. Engineers have to design structures higher off the ground, with buffer regions in the foundation against the fear of floods.

Levees built to handle loads far exceeding what one might consider normal has been put in place, simply to prepare for the future of storms and weather. 

It is in this glimpse of extreme reality that we can gain perspective on the growing scope of modern structural engineering.

Structural engineering is no longer a matter of making sure the building stands under standard loading conditions, rather it is also a game of predicting what extremes the structure may face over its proposed lifetime and determining whether designing for those loads now is worth it. 

Some areas are becoming off limits for construction

The discussion around how structural and building design is being forced to change would not be complete if we did not talk about places where structural design can no longer happen or rather, is no longer economically feasible.

Flood plains are becoming larger and larger with the increased probability of storm, that is why modern cities are running out of space. Flood plains may seem like a viable building space to an untrained eye, after all, they are dry 99% of the time.

However, when cities do expand into these flood plains, catastrophic disaster to housing and businesses simply becomes a when, rather than an if. 

But it is not just the flood plains that are growing in size and making building unviable or impossible in that region, it is also areas of extreme drought.

Building a structure is not the whole picture. After it is built, you also have to support it with the necessary infrastructures like water and sewage. Extremely drought-stricken areas make this harder.

Engineers have to figure out where they are going to source the water for the expected occupants in a building's design, and now, more regions are off limits because water simply cannot be economically sourced. 

Increased storms bring increased structural design

When engineers are going through calculations for different weather-dependent loading conditions – like wind, rain and snow – they often design based around conditions suited for 50-year or 100-year storms.

This terminology does not mean that the storms happen at these determined intervals, rather, these are just the probability of the storms happening in that interval. In actuality, they can happen more frequently – and thanks to climate change, they are indeed happening more frequently.

Designing for a 50-year storm or a 100-year storm can mean significantly increased costs in the building design and construction phase.

Engineers and developers are now faced with changing loading conditions due to climate change and are being forced to take a more conservative approach in their processes, designing for higher loads than what standards might infer, simply because it is highly likely that climate change will soon change what the standard design loads indicate as standard.

What the future for structural design might bring

When you grasp the full scope of a structural engineer's job and how design is dependent upon weather loading conditions of a structure, you can understand how climate change will likely shape and transform the current building design process. 

We have only mentioned a few different aspects of how structural engineers are having to grapple with the effects of climate change. However, engineers are increasingly having to consider frequent fires in their design.

This is causing them to rethink their choice in materials, shifting to much-less flammable supplies. 

Engineers are also having to consider the infrastructure needed to support different aspects of a building, things like electricity and storm drains.

Frequent high-power storms are likely to cause more frequent power outages, which means that building support systems can be left lifeless for far longer periods. Should the developers design their buildings with on-site generators or power banks? These are the questions that they have to tackle. 

Water management an unseen necessity

In terms of storm drains though, water management is an unseen necessity of good building design. As storms get bigger, drainage becomes an even bigger hurdle that engineers have to design for during their structural design.

The water has to be managed somehow, and in many cases, this simply means more drains, bigger pipes, and ultimately, more construction expenses. 

The strategies that engineers are developing for adapting building construction and design to the effects of climate change are fairly simple in theory.

However, when you account for all of the little changes that have to be made and considered in the design process, it ultimately equates to a far harder line of work than it was in the past. 

Change is likely to make structural design more expensive, while a simultaneous rise in poverty could create a perfect storm. The buildings get more expensive to build and the population becomes less able to build them.