When it comes to big home projects, you often find yourself confronted with a list of professionals that leaves you scratching your head. One of the biggest offenders is the structural engineer. Just what exactly do they do, and why do you need one?

Let’s find out…

What Is A Structural Engineer?

A structural engineer is an engineer that specialises in building structure. They will design, plan, and oversee the construction of structures such as buildings.

A structural engineer will often act as a consultant to an architect or building contractor, calculating loads, defining the spec of the project, and which materials and structural systems to use during construction, such as steel, concrete, or wood.

The structural engineer will assess the safety, strength, and durability of the building or structure to determine its structural integrity.

When would I need one?

There are several occasions when you might need to enlist the services of a structural engineer.

For Renovations

When you’re making home improvements that involve the stability of a building you will probably need a structural engineer. This engineer will provide structural drawings and calculations which will be used by your building contractor and architect during the renovation work.

This information may also need to be provided to Building Control in order to comply with Building Regulations or, depending on the scale of the renovation, to Planning Officials in order to obtain planning permission. 

Whether or not you’ll need a structural engineer for your renovation will depend upon the nature of the project. Those which often require the services of a structural engineer include:

  • Building an extension

  • Modifying doors and windows

  • Fitting solar panels

  • Loft conversions

  • Removing or modifying internal walls

  • Underpinning floors

  • Removing a chimney breast

This is not an exhaustive list however. As a general rule anything which changes the structure of the property will need building control approval and to obtain this you’ll need technical information from a structural engineer.


For Structural Inspections

Structural engineers are not just needed for property renovations. If there is a problem with the structure of your property – from signs of subsidence such as movement or cracking walls or sagging ceilings or roofline – you may need a structural engineer to carry out an inspection.

It could also be that a chartered surveyor you have appointed to conduct a survey of the property you want to buy identifies structural issues and advises you to have a more detailed investigation of the issue from a structural engineer.

Alternatively, you may notice cracks or other causes of concern in your property and decide to instruct a structural engineer to assess the damage, identifying possible causes and treatment.

For an Expert Witness

You may also need to enlist the services of a structural engineer if you find yourself in a disagreement with another party over a structural matter related to your home. A structural engineer can provide an unbiased view, in the form of an independent report and advice on your options.


Two Examples of Where Architects and Structural Engineers Work Together:

If you were planning a large house extension in your rear garden, the architect will create the drawings and specify where the supporting steel joist will be placed, but the structural engineer will calculate the size of the joist and this will be based on the weight of the structure above the joist and the length of the opening it covers. If the architect cannot specify a joist that fits in with the design by the architect, they work together to create a solution, this could be, for example, adding an extra supporting wall or pillar or using different materials.

If your extension was located on ground that slopes away from the house, the architect will specify where the foundations are to be located but the structural engineer will decide how deep they should go. 1.2 metres is the norm, but for ground that slopes away or soft soil, 2 metres could be specified. In extreme circumstances, the structural engineer may decide that piling deep into the ground is the only way to ensure a sound foundation.

How much does a structural engineer cost?

The price of your structural engineer depends on three things:

  • The size of your project

  • The type of project

  • The location of your engineer

For any project like an extension, you’re likely to be looking at costs ranging from £750-£1500 (incl. VAT). This should cover your site visit, production of calculations, and the drawings / plans produced in the end.

How can A9 Engineering help?


Our in-depth industrial experience enables us to provide Building Structural Design Consultancy Services to the clients. Our range of services is widely acclaimed by our clients for its key features such as timeliness, prompt service and economical rates. Our experience is varied and it ranges from beam design of domestic property to multi-storey building design, from ground investigation to foundation design, from retaining wall design to house extension, loft conversion. Our structures are sturdily constructed in compliance with set industrially approved standards. In addition to this, these services are available at leading market prices.


BlogAlan Green