Most people only ever need to hire a structural engineer once or twice in their life, which means most people have no idea what actually separates a good one from a bad one until it’s too late. That’s not a criticism, by the way. It’s just not the kind of thing anyone teaches you.

We get the same questions from clients over and over: what does a structural engineer actually do that an architect doesn’t? Does “chartered” actually mean anything? And how do you tell the difference between someone who’s genuinely good and someone who just has a nice-looking website?

Here’s what we’ve learned from being on the other side of that decision, project after project.

What a structural engineer actually does (and doesn’t)

An architect designs how a building looks and works as a space. A structural engineer works out how it stays standing. Those two things overlap more than people expect, especially on anything involving knocking through walls, extending upward, or building on tricky ground, but they’re not the same job, and one can’t really substitute for the other.

A good structural engineer will look at your existing building, understand what’s currently holding it up, and work out exactly what needs to change to support your new plans safely, without over-engineering it into something needlessly expensive. That last part matters more than people think. Under-engineering is dangerous. Over-engineering just quietly costs you money for no benefit.

Builders, for what it’s worth, are not a substitute either, however experienced they are. A builder who’s “done loads of these” is working from experience and instinct. An engineer is working from calculation. Most of the time those two things agree. Occasionally they don’t, and that’s exactly the situation you want caught on paper before the wall comes down, not after.

Does “Chartered” actually matter?

Yes, and here’s the honest reason why: chartered status through the Institution of Structural Engineers (IStructE) or the Institution of Civil Engineers (ICE) means someone has been independently assessed against a professional standard, not just self-declared as competent. It also usually means they’re required to carry proper professional indemnity insurance and stay current with their continuing professional development.

None of that guarantees you’ll like working with them. But it does mean there’s a real, external standard behind the qualification, rather than just a job title someone gave themselves.

If you’re comparing quotes and one engineer is noticeably cheaper than the rest, it’s worth asking directly whether they’re chartered, and if not, why not. Sometimes there’s a perfectly reasonable answer. Sometimes there isn’t.

Questions worth asking before you hire anyone

A few we’d suggest asking, because the answers tell you a lot:

• Have you worked on a project like mine before, specifically in this area or on this type of building?
• Will you visit the site yourself, or send someone else?
• What’s included in your fee, and what would trigger extra charges?
• How do you handle it if Building Control comes back with questions on your design?
• Can I see an example of a similar project you’ve done?

Anyone who gets defensive about these, rather than just answering them, is telling you something.

Local knowledge is worth more than people assume

This one surprises people. A structural engineer who works regularly in your area will already know things that would otherwise take extra investigation: what the ground conditions are typically like nearby, how the local council’s building control team tends to interpret certain regulations, and what’s likely to come up on a Victorian terrace versus a 1960s semi versus a new-build plot.

That familiarity doesn’t replace a proper site visit and calculation, but it does mean fewer surprises, and often a faster, smoother process from first call to signed-off design.

Don’t just chase the cheapest quote

We say this as gently as we can: the cheapest quote is sometimes cheap because something’s been left out, not because someone’s simply more efficient. A thin structural report that doesn’t actually address the tricky part of your project isn’t a bargain, it’s a problem you’ve paid to postpone.

What you’re really paying for is judgement: knowing which parts of a project genuinely need close attention, and which don’t. That’s not something you can easily compare on a spreadsheet, but it’s the thing that actually determines whether your project goes smoothly or turns into a headache six weeks in.

A few signs you’re dealing with someone good

• They ask you questions before quoting, rather than pricing blind off a phone call
• They’re upfront about what they don’t yet know until they’ve seen the site
• They can explain their reasoning in plain English, not just jargon
• They’re not the only person who’s ever seen your kind of project

Where we fit into this

We’re a chartered structural engineering practice working across Peterborough, London and the surrounding areas, and we’ve built our reputation on exactly the things above: turning up, doing the calculations properly, and explaining what we find in a way that actually makes sense. If you’re at the stage of comparing engineers for an upcoming project, we’re always happy to have an honest conversation about whether we’re the right fit, before any commitment is made.

Frequently asked questions

Do I need a structural engineer or an architect first?

It depends on the project, but for anything involving structural changes, it’s often worth speaking to both early on. A good architect will usually tell you when structural input is needed.

Can I use a structural engineer who isn’t local to me?

You can, and sometimes it’s unavoidable for specialist projects, but expect it to take slightly longer for site visits and for them to need more time to get familiar with local ground conditions and council requirements.

How do I check if someone is actually chartered?

Both IStructE and ICE have public member directories you can search directly on their websites, so you don’t have to just take someone’s word for it.