How Much Does a Knock Through / Structural Wall Removal Cost in the UK? Complete Guide (2026)

A knock through—also known as removing a structural wall to create an open-plan space—is one of the most popular home renovations in the UK. It is typically done to combine kitchens and dining rooms, living rooms and hallways, or to create a modern open-plan layout.

However, because structural walls are load-bearing, this is not a simple demolition job. It usually involves steelwork (RSJs), structural calculations, building control approval, and professional installation.

So how much does a knock through cost in the UK in 2026?

Average Knock Through Costs in the UK

The cost of removing a structural wall depends mainly on wall size, load-bearing requirements, and access.

Typical UK costs are:

• Small structural wall removal: £1,500 – £3,000
• Standard single wall knock through: £2,500 – £5,500
• Large open-plan structural removal: £5,000 – £10,000+
• Complex multi-wall or beam installation: £8,000 – £15,000+

For most UK homes, a typical knock through project costs between £3,000 and £7,000.

What Is Included in a Knock Through?

A proper structural wall removal is more than just knocking down bricks. A full professional job usually includes:

• Structural engineer survey and calculations
• Installation of RSJ steel beam(s)
• Acrow props and temporary supports
• Wall demolition and waste removal
• Making good (plastering, finishing, patching)
• Building control inspections and approval

In many cases, electrical or plumbing rerouting may also be required.

RSJ (Steel Beam) Installation Costs

The RSJ is the most important structural component of a knock through.

Typical costs:

• Small RSJ installation: £800 – £1,500
• Standard RSJ for internal wall: £1,200 – £2,500
• Large steel beam installation: £2,500 – £5,000+

Costs increase depending on beam length, load requirements, and whether cranes or lifting equipment are needed.

Structural Engineer Costs

A structural engineer is required for nearly all load-bearing wall removals.

Typical costs:

• Basic structural survey: £250 – £500
• Full calculations and drawings: £400 – £900
• Complex structural design: £800 – £1,500+

These calculations are essential for building control approval and safe installation.

Building Control Costs

You must notify your local authority or use an approved building control process for structural changes.

Typical costs:

• Building control application: £200 – £900
• Inspections during works: included or additional depending on council
• Completion certificate: included upon sign-off

Without this, selling your property later can become difficult or require retrospective approval.

Labour Costs for Knock Through Work

Labour is a major part of the total cost and depends on complexity.

Typical labour costs:

• Simple wall removal (non-structural elements): £500 – £1,000
• Structural wall removal labour: £1,500 – £4,000
• Complex structural alterations: £4,000 – £8,000+

This includes demolition, installation of supports, and finishing work.

Waste Removal and Making Good

Once the wall is removed, there is always finishing work required.

Typical costs:

• Waste removal (skip hire): £200 – £500
• Plastering and making good: £300 – £1,200
• Floor and ceiling repairs: £200 – £1,500

If you are creating a fully open-plan kitchen, finishing costs can increase further.

What Affects Knock Through Costs?

Several key factors influence the final price.

1. Whether the Wall Is Load-Bearing

Non-structural walls are cheap to remove. Load-bearing walls require steel beams and engineering input.

2. Size and Span of the Opening

Wider openings require larger steel beams and more complex support systems.

3. Property Type and Age

Older properties often require additional reinforcement, unexpected structural fixes, or more complex beam designs.

4. Access to the Property

Restricted access increases labour time and waste removal costs.

5. Electrical and Plumbing Work

If services run through the wall, relocation adds extra cost.

Do You Need Planning Permission for a Knock Through?

In most cases, you do not need planning permission for internal structural alterations.

However, you will always need:

• Building control approval
• Structural engineer sign-off

Planning permission may be required if:

• The property is listed
• External structural changes are involved
• You are altering the building’s external appearance

Always check with your local authority before starting work.

How Long Does a Knock Through Take?

Typical timelines:

• Simple structural wall removal: 2–3 days
• Standard knock through with RSJ: 3–5 days
• Full open-plan kitchen conversion: 1–2 weeks

Additional time may be required for plastering and finishing.

Does a Knock Through Add Value to a Property?

Yes—when done well, a knock through can significantly improve property value and buyer appeal.

Benefits include:

• Modern open-plan living space
• Improved natural light
• Better flow between rooms
• Increased perceived space

In many UK homes, open-plan layouts are a major selling point.

Ways to Save Money on a Knock Through

To reduce costs:

• Combine multiple works into one structural job
• Keep services (plumbing/electrics) in place where possible
• Get multiple structural quotes
• Avoid unnecessary widening of openings
• Plan finishes separately to control budget

Knock Through Cost Calculator

The most accurate way to estimate your project is with a personalised breakdown based on:

• Wall type (load-bearing or non-structural)
• Size of opening required
• Structural engineer requirements
• RSJ specification
• Finishing and making-good work

Pricing Penguin’s AI-powered cost calculator uses real UK structural project data to generate instant, tailored knock through cost estimates for your property.

Final Thoughts

A knock through is one of the most impactful home improvements available, transforming dated layouts into modern open-plan living spaces.

In 2026, most UK structural wall removals cost between £3,000 and £7,000, with complex projects reaching £10,000–£15,000+.

When planned correctly with proper structural input, it is a highly effective way to increase both lifestyle quality and property appeal.