What is a Structural engineer? do I need one?
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Do I need a structural engineer?

When you start a building project you’ll be presented with a long list of professionals you need to engage in order to complete it. There are some on there that you’ll be used to seeing: builders, decorators, electricians, plumbers, etc. There might also be some that you hadn’t realised were so important. One of those is a structural engineer.

But what exactly is a structural engineer, what do they do and why would you need one?

What is a structural engineer?

Specialising in the structure of buildings, structural engineers design, plan and supervise the construction of permanent structures like buildings. They can also be used in projects like public monuments (statues, fountains, etc.).

The structural engineer will consult with any architectural designer or building contractor in many aspects of the building of a structure. For instance, they will often calculate loads, define the specifications of the project, and determine the best materials/structural systems that should be used during construction (i.e. should wood or concrete be used).

There are other very important safety duties that the structural engineer will undertake during a project too. They will assess the building’s safety, durability and strength. This will help them to determine the building’s structural integrity and whether it’s safe for habitation/use.

When would you need a structural engineer?

There are several reasons why you might need the services of a structural engineer. Here’s a quick list of the potential scenarios and when you might need them.


Home improvements are one of the common reasons why structural engineers are needed. Any work on your home could impact the stability of your building. The engineer will, therefore, produce a structural drawing of your building with calculations that can be used by other professionals throughout the project to complete their work.

The work completed by the structural engineer might also need to be provided in order to show that the renovations are adhering to building regulations. If your renovations are particularly large enough, then your structural engineer’s drawings might be required to obtain planning permission.

There might be some cases when the structural engineer isn’t required. However, for most renovations, you will probably be required to hire a structured engineer. Examples of what renovations you will need a structural engineer for include:

* Adding an extension to a property.
* Installing renewable power sources (i.e. solar panels) to a property.
* Modifying any doors and windows throughout the property.
* Converting a loft/basement for habitation or other use.
* Modifying or removing an internal wall.
* Underpinning any floors.
* Modifying or removing a chimney breast.

This list is not exhaustive, there are other projects where they might be required, but the vast majority of structural engineer services London are rendered for these tasks.

However, as a general rule, if your project will make any changes to the structure of the building where you will require approval from building control or planning permission, you’ll have to use the services of a structural engineer.

Structural inspections

Not all work that is carried out by a structural engineer is for adding or modifying properties. Sometimes they’re called in when there’s no new work planned but there might be problems with the structure of a property.

There might be numerous problems that would need the assessment of a structural engineer. This includes when there are signs of subsidence. These signs include the movement/cracking of walls and where there are visible signs of sagging in the ceilings or rooflines.

If this is the case, the structural engineer will be called in to carry out an inspection on the property. They will then advise on what is going on and what is probably going to be required to make the property structurally sound again.

You might also require the services of a structural engineer when a chartered surveyor has identified issues in the structure of the property. They will advise that a more detailed investigation will be needed and this would need to be carried out by the structural engineer.

Finally, you might just decide to call in a structural engineer when you notice new cracks in your building or if there are other concerns. In this role, they will visit the property, inspect the damage and identify the cause and treatment required.

Expert witness

There are also times when you might need a structural engineer to act as a witness for a property dispute. This is often the case when there is a disagreement with a third-party (i.e. neighbour) over a structural matter connected to your property.

The structural engineer will inspect the situation and provide an unbiased view of the current situation. They will then write an independent report and offer advice on the options available to you.

You can use these expert witness reports to make your case and these can be used by lawyers (if necessary) to come up with some agreement.

How much will I need for a structural engineer?

The cost of hiring a structural engineer for a project is a complex question. There are many factors that can impact the overall cost. Some of those factors include the type of project you’re completing, the size of the project and the location of the project.

There are also varying prices between those who offer structural engineer services London-wide.

For those who are looking to build an extension, the cost of the work is probably going to be around £750 to £1500, depending on the factors listed above. This would include VAT. This cost would include all aspects of the service including the site visit, the production of calculations and any drawings/plans/reports that were developed as a result of the work.


The work of a structural engineer is very important and varied. If you’re making any changes to your home where you’re directly making alterations to the physical structure, you’re probably going to need a structural engineer.

They will work tirelessly to ensure that your property remains safe and all building work still adheres to building regulations in your area.

Searching for ‘structural engineer services London’? Give us a call and our professional team can help you out today.