Do I need a structural engineer and what do they do?

If you’re undertaking any kind of home renovation or building project you may have come across the term structural engineer. But what is a structural engineer and why do you need one? Howard Clarke of Plan Structures Ltd talks us through it.

Tell us about what you do

In a nutshell, my job is to ensure that a building is structurally sound. The architect will design the building, and my job is about creating and maintaining its strength and stability.

So you prevent our homes from falling down?

It’s a bit like the skeleton in the human body. The foundations, walls, beams and columns are the bones supporting the entire weight of the building. Take an existing house and remove one of the supports, like a wall or a chimney breast, and you alter its structural integrity. Potentially, you are weakening the whole thing. My role is to calculate what measures need to be put in place to mitigate that.

“It’s all about balance. If you add something in, take something away, or change it significantly, you must offset that change.” – Howard

What might cause a building to move or collapse?

Your house is vulnerable to lots of stress, especially as it’s exposed to everything the elements can throw at it. In the UK, earthquakes and hurricanes are rare events and your house is unlikely to collapse. But all buildings are designed to move slightly, we just don’t usually feel it. High winds are the main cause of instability (one of the engineer’s biggest concerns!) which can lead to cracking. This is why most modern buildings are engineered to withstand severe gales and even hurricanes. Other environmental factors include the kind of ground your house rests on and whether there are large trees nearby which could cause movement.

What kind of work do you advise on?

New buildings of course, but any extension to your home, upwards or sideways, is likely to drive a need for additional support. I will calculate the load that a structural beam is required to support for example. Similarly, a loft conversion will place more load on the existing structure of your home and may impact the roof and floor joists etc. I can work out how we build a conversion that is strong and safe. This is when you need a structural engineer. Removing an internal wall Creating an open plan space in your home by removing or altering internal load-bearing walls or swapping bricks for glass, also means removing some of the building’s supporting structure. It’s part of my job to determine how the architect’s designs can be realised while retaining stability, strength and rigidity. Most of my projects are residential alterations, extensions and conversions. But I’ve worked on new builds, schools and offices, underpinning projects and advising on adding solar panels.

When does the structural engineer get involved in a project?

It depends. Often, I’ll come in after the architect has done the designs and planning permission has been granted. At that point, I will examine the plans and calculate the structural or load-bearing implications. It’s always useful to be involved from the beginning and work with the architect on the designs, to ensure that the plans will work in practice. Then I’ll undertake the complex calculations required to make the building strong and solid. Architect and structural engineer as a team In an ideal world, all construction projects would be collaborative affairs. The architect and structural engineer would work in synergy to design a building that looks great, is fundamentally robust and can be constructed to a high standard by a good builder.

Do I need a structural engineer and will you need to come and see my house?

When you decide to make changes to an existing building, you don’t know what you’re going to find when you start to peel back the layers. Your architect will probably advise if they think you need a structural engineer. No one has x-ray vision, but by visiting the property I can get a much better sense of the structural nature of the building. Plus, talking to the owners can be valuable as they know their house best; the odd remark or detail mentioned might tell me something really useful. Like ‘when we drilled into this wall this happened.’ It helps to reduce uncertainty. And it’s often helpful for you to hear it straight from the horse’s mouth. I will explain why your extension is going to need that huge beam, the implications of replacing a wall with glass doors or taking out a chimney.   The information contained in this article is for general informational purposes only, does not constitute professional advice and does not necessarily reflect the official policy or position of any company or organisation. Readers should always seek professional advice before undertaking any action based on the information contained in this article. The author makes no representations or warranties of any kind, express or implied, about the completeness, accuracy, reliability, or suitability of the information, products, services, or related graphics contained in the article for any purpose.