Need to know how much does a structural engineer cost for your loft conversion, extension or demolition project? You're in the right place.

In this price guide, discover:

• Average structural engineer costs

• What affects prices

• Why hiring a certified structural engineer keeps your build safe and avoids costly repairs later down the line

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Structural engineer costs

The average structural engineer cost is £1,000 for a basic residential project and £5,000 for a complex residential project.

Meanwhile, the average hourly rate for structural engineers is £100–£200.

So far, so simple. But here's the thing to know about structural engineer prices. The more complex the structure, the more time and in-depth knowledge the tradesperson will need.

Let's look at structural engineer costs in more depth to give you a clearer picture. But first, what does a structural engineer do?

What does a structural engineer do?

Structural engineers wear many hats, including:

• Residential or commercial: From houses and flats, to offices, shops, bridges and even factories

• Safety: Ensuring the safety of all involved with every project

• Structure and support: Checking plans, suggesting changes, and recommending the most suitable materials

• Planning permission and regulations: Submit planning permission for all jobs they are involved in and ensure that building regulations are complied with

• Structural inspections: Conducting an inspection to ensure the building is structurally sound before a homeowner purchases a new property

• Removals: Assist with removing walls, floors and doorways by assessing whether extra support is needed to maintain the safety and security of a building

Cost of structural engineer by project

Let's look at the four most common jobs a structural engineer can help with and the costs involved:

1. Structural engineer inspection cost

It can be useful to hire a structural engineer to inspect a new property before putting in an offer if there's cause for concern, such as cracks:

• What the engineer looks at: Structural condition, cracks, movement, and potential safety concerns

• What's included: A site inspection which normally takes two to three hours, depending on the size of the property

• Cost: The average cost of a structural engineer inspection is £300

2. Structural engineer report cost

Following a building inspection, a structural engineer will compile a building report (also known as a structural survey). But what's in a structural engineer's report, and how much does a structural engineer's report cost?:

• What the engineer looks at: This in-depth report looks at the different parts of a structure, their condition and any recommendations for repairs

• What's included: A written report detailing findings (such as problems with load-bearing walls or foundations) and recommended remedial work

• Cost: The average structural engineer report cost is £700, plus the cost of the site visit (£300)

3. Structural engineer costs for RSJ calculation

RSJs or rolled steel joists are beams designed to support loads in any building, in particular doors or when removing load-bearing walls (a common job when creating open-plan living spaces):

• What the engineer looks at: The loads the beam needs to support and how they will be distributed through the structure

• What's included: Structural calculations, beam specifications, and documentation for Building Regulations approval

• Cost: The average structural engineer's cost for an RSJ calculation is £200

4. Cost of structural engineer for load-bearing walls

If you are considering removing a load-bearing wall or are unsure whether a wall is load-bearing, you'll want a structural engineer to take a look:

• What the engineer looks at: Whether the wall is load-bearing and how its removal will affect the structure

• What's included: A structural assessment to confirm whether a wall is load-bearing, specify the steel beam required, and sign off drawings for building regs

• Cost: The average cost of a structural engineer for load-bearing walls is £400

5. Structural engineer costs for extensions

You'll almost always need a structural engineer during the planning stage of an extension:

• What the engineer looks at: Removal of load-bearing walls, installing steel beams, or digging new foundations

• What's included: Site visit, calculations, drawings, and building regs sign-off

• Cost: A structural engineer's cost for a loft conversion typically starts at around £1,000 for a standard single-storey extension, but can increase threefold for a larger, double-storey build

To get a clearer picture of how much a structural engineer costs for a house extension, try our cost calculator below for an instant estimate.

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Factors affecting structural engineer costs

Structural engineer prices will vary widely from job to job. The most important factors when determining costs are as follows:

• Complexity of a project: Larger jobs, such as house extensions will cost a lot more than smaller projects, such as removing a window

• Size of current property: A structural engineer's calculations to check whether a small flat is structurally sound will be much quicker and therefore cheaper than checking a large home

• Project type: As structural engineers cover a wide range of jobs, each project will vary in cost. For example, an assessment of a structure will usually be cheaper than the planning and implementation of a large renovation

How long does a structural engineer take?

Most structural engineering work is completed within one to three weeks, from the first visit to the report delivery. This boils down to:

• Site inspection: Two to four hours

• Written calculations or report: Typically follow within five to ten working days

That said, more complex design work for extensions or loft conversions can take longer – factor in three to four weeks if you're on a planning timeline.

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Do I need a structural engineer?

You must hire a structural engineer if you're making any changes to your property that alter the structural integrity, such as removing walls, adding extensions, or converting a loft.

Structural engineers are highly trained professionals who assist with:

• Safety issues, such as checking how viable or secure a structure will be

• Suggest changes to ensure a project is structurally sound

• Helping with choosing the correct materials for your building designs

Structural engineers cost checklist

• Get at least three quotes from structural engineers to compare costs

• Check what's included (site visit & survey?)

• Ask how long it will take (a site visit can take on average two to four hours)

• Scope out availability early doors (the best structural engineers will often get booked up in advance)

• Check if their work comes with a guarantee and if they are insured

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Up to £1000. Eligibility criteria and T&C’s apply.

Find certified structural engineers near you

To find certified structural engineers in your area and get a personalised structural engineer cost, request a quote, download our Checkatrade app, or search your postcode.

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• Checked - Every Checkatrade member must pass up to 12 checks and commit to upholding the Checkatrade Standard

• Guaranteed - Jobs booked through Checkatrade are covered up to £1,000 (T&Cs apply)

• Reviewed - Over 6.2 million verified reviews from real jobs have been published on Checkatrade on everything from communication, tidiness, timekeeping, and quality of work

Your building project may require several different skills, but at Checkatrade, we've got you covered. Find checked and reviewed plumbers, electricians, plasterers, carpenters, and more, all in one handy place, all committed to quality and a job done right.

FAQs

How much does a structural engineer cost per hour?

The average hourly rate for structural engineers is £100–£200. However, most smaller jobs, such as a load-bearing wall assessment or an RSJ calculation, are charged at a fixed fee rather than hourly.

Do I need a structural engineer to remove a wall?

Yes, if the wall is load-bearing, you'll need a structural engineer. A structural engineer will specify the steel beam needed and provide drawings for building regulations sign-off. You can't safely remove a load-bearing wall without this.

How much does a structural engineer cost for a loft conversion?

A structural engineer cost for a loft conversion all depends on the complexity and size. But as a general steer, the average cost for an inspection is £300 plus the report cost of £700. They'll check whether the existing floor joists need strengthening, specify any new steelwork, and produce drawings for building regulations.

What does a structural engineer report include?

A structural engineer's report covers the condition of the structure, any areas of concern (such as cracks, movement, or damp), recommendations for repairs or further investigation, and calculations for proposed work. The average structural engineer report cost is £700, plus the cost of the site visit (£300).

What's the difference between an architect and a structural engineer?

An architect focuses on the design and layout of your home improvement project, creating plans that show how the finished space will look and function. A structural engineer focuses on safety and stability, assessing load-bearing walls, foundations, and structural changes to make sure the building remains safe and compliant. For larger projects, you may need both professionals.

Is a structural engineer the same as a surveyor?

A surveyor (such as for a homebuyer survey) assesses the general condition of a property and flags potential issues. A structural engineer goes deeper by carrying out a detailed analysis of structural elements and providing certified calculations and drawings. For any structural works, you need an engineer, not just a surveyor.

How long does a structural engineer report take?

The site visit usually takes two to four hours. The written report or calculations follow within five to ten working days, though complex projects can take longer.

Always check turnaround times when getting quotes from chartered surveyors, especially if you're on a planning deadline.

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