When you do NOT need a structural engineer

Structural engineers are often associated with any building work, but the reality is more nuanced. There are situations where engineering input adds little value — and we find that being honest and clear about this builds trust with our clients and helps them to make better decisions.

Situations where engineering adds little value

Structural input is generally unnecessary where works do not affect loadbearing elements or alter how loads are transferred through a building.

Typical examples include:

• Internal finishes and refurbishment that do not alter structure

• Like-for-like replacement of non-structural elements

• Minor openings within non-loadbearing partitions

• Installation of fixtures that do not materially increase loads

In these cases, the risk is low and structural design is unlikely to be required.

Specific example

We are occasionally approached for involvement on projects when we are not actually required, and we will explain to the potential client why this is the case. We were recently asked to visit a property to advise on the removal of in-built wardrobes within a property. Since it is unlikely that this is a structural element we recommended that they appoint an experienced and competent builder to inspect instead.

Minor works examples

Many small projects fall into this category, particularly domestic or light commercial works.

Examples often include:

• Replacing windows or doors within existing openings (as long as lintels are already present),

• Kitchen or bathroom refurbishments without structural alteration,

• Installing lightweight rooftop equipment within typical allowances,

• Non-structural external works, such as small garden retaining walls or patio works.

The key question is always whether the structure is being changed — not simply whether building work is occurring.

Building control thresholds explained

The Building Regulations requires justification where structural elements are altered, added or their loading changes. For example, this would apply if the work affects:

• Loadbearing walls,

• Beams, columns or floors,

• Foundations,

• Roof structure,

• Significant new loads.

Where these elements are present, building control will likely request structural calculations. It is much better for your project if we are involved upfront, rather than leaving our involvement until Building Control request evidence of adequacy. It is far more difficult for us to validate works that are already underway than it would have been to have designed it properly initially. There is also often a delay to the scheme whilst we gain an understanding of what has already been carried out, what we need to design, and then the time involved in actually preparing the design.

Specific example

In some instances, it is not clear to those involved in building alterations whether a wall is actually loadbearing to structure above, particularly if the wall in question is formed with timber studwork. A common misconception is that a timber stud wall cannot be loadbearing, whereas the truth is that it can, just ask the Tudors!

This can lead to situations where the builder or the Building Control Officer may require confirmation whether the wall removal requires replacement structure. When this is not determined until construction stage the builder cannot progress until it is resolved.

Grey areas — where advice still helps

Some projects sit between clearly structural and clearly non-structural, such as;

• Removing walls where loadbearing status is uncertain,

• Installing heavier plant, equipment or PV panels,

• Alterations within older or undocumented buildings,

• Changes of use that alter loading assumptions.

In these situations, a short review can prevent incorrect assumptions and avoid delays later.

The risk of assuming you don’t need a Structural Engineer

The main risk is not cost, it is incorrect assumptions.

Misidentifying loadbearing elements, underestimating loads or overlooking stability can lead to redesign, programme delays or remedial works. A brief professional review early is often cheaper than resolving issues during construction.

A simple decision checklist

You may not need a structural engineer if:

• No loadbearing elements are being altered

• No significant new loads are introduced

• The structural system remains unchanged

• Building control has not requested structural information

You should seek advice if there is uncertainty on any of the above.

In practice, many enquiries involve confirming whether engineering input is required rather than delivering full design and early clarification helps projects move forward with confidence and avoids unnecessary work.

When we are approached with a request to assist on a project, we would ask for information that would allow us to envisage what we would undertake and provide to the client. Doing so allows us to determine what amount of time might be involved, and therefore what fee should be charged.

If you have a project that you would like us to advise you with, we would ask you to send us;

• any drawings of the proposal that you might have,

• any photographs of the area in question,

• any specific requirements that you might have (such as which parts of the structure require design, any concerns that you may have for the existing building or ground, etc)

• the exact project location

• any timescale requirement or limitations.

  
  

Once we have reviewed the above information we would provide you with a detailed quotation that explains what we would provide, when we would provide it, and how much it would cost. We also make a point of highlighting any elements or parts of the scheme that we have not included for, to ensure that you understand what you are going to receive.

Please contact us if you have a project that may require structural input and we will be happy to provide some initial outline advice without cost.