Wall Construction Types, What You Need To Know!

How to Identify Common Wall Types and Their Typical Thicknesses

Understanding the type and thickness of your home’s walls is essential, whether you’re planning renovations, installing insulation, or just curious about your property’s construction.

At Surveying Cymru, we conduct property surveys and we’re often asked:

“How thick should my house walls be?” or “Is this a cavity wall or solid wall?”

This guide covers the most common wall construction types found in UK homes and gives you tips on how to identify each one, along with the typical wall thickness for each style.

Cavity Walls

Cavity walls are among the most common wall types in UK houses built from the 1930s onward. These walls are made up of two masonry layers (known as “skins”) separated by a hollow space or cavity.

The outer and inner walls are usually brick or concrete block, tied together using wall ties. The cavity can either be empty (in older properties) or filled with insulation.

Key Features:

• Seen in post-1930s homes
• Two layers with a visible gap between
• May include cavity wall insulation

Typically, the wall thickness would measure 220mm to 320mm, depending on materials and insulation.

Timber Frame Walls

Timber framed wall construction is a lightweight system where the structural load is carried by a frame made of small timber studs. These walls are then clad internally with plasterboard and externally with materials like brick, render, or weatherboarding.

Timber frame homes became more popular in the UK from the 1960s onward, particularly in newer developments and energy-efficient builds.

Key Features:

• Quick to construct
• Often used in modern housing estates
• May sound more hollow when tapped

Typically, the wall thickness would measure 100mm to 200mm, though modern builds may be thicker depending on insulation layers.

System-Built Walls

System-built homes were popular in the UK between the 1940s and 1970s, especially during post-war housing booms. These walls were constructed using pre-cast concrete panels or poured solid concrete, sometimes with a metal or timber frame.

You may also hear them referred to as non-traditional construction.

Key Features:

• Often seen in post-war housing
• May be concrete panels or cladding
• May require specialist survey methods

Typically, the wall thickness would measure 200mm to 300mm, depending on the system used.

Solid Brick Walls

Solid brick walls are common in homes built before the 1930s, particularly Victorian and Edwardian properties. These walls consist of a single solid structure, either two layers of brick without a cavity or a concrete block with an outer facing of brick.

One way to identify a solid brick wall is by looking at the brick pattern on the exterior. If you see a mix of brick ends (headers) and longer sides (stretchers), it’s a strong indication of solid brick construction.

Key Features:

• Found in pre-1930s homes
• No cavity between wall layers
• Distinctive brick bond patterns

Typically, the wall thickness would measure 100mm to 250mm, depending on materials and mortar depth.

Solid Stone Walls

Solid stone walls are typically found in older properties, especially rural cottages and traditional terraced houses built before 1900. Common types of stone include sandstone, granite, or whinstone.

These walls are often very thick, with natural variation due to the irregularity of stone sizes and building techniques.

Key Features:

• Uneven or irregular appearance
• Found in period homes and heritage buildings
• Often very thick and solid

Typically, the wall thickness would measure 400mm to 600mm, depending on stone type and local building style.

How to Tell What Wall Construction Type You Have

Here are a few ways to identify your wall type:

• Tap the wall: A hollow sound may suggest timber frame
• Check the brick pattern: Mixed header and stretcher layout = solid brick
• Measure the depth of window/door reveals: Thicker reveals may suggest solid stone or cavity wall
• Review construction date: Homes built after 1930 are more likely to have cavity walls
• Use thermal imaging: Can reveal cold bridging or voids in insulation

Still unsure? A professional property survey can confirm your wall type and help you plan insulation or renovation works properly.

📞 Need expert help identifying your wall type? Contact Surveying Cymru today for friendly, impartial advice.

Why Wall Thickness Matters

Knowing your wall type and thickness isn’t just for curiosity,  it has practical implications:

• Insulation suitability: Not all insulation types work for every wall
• Damp risk: Solid walls are more prone to moisture problems without ventilation
• Structural limitations: Some wall types can’t support extensions or certain fixings
• Home value: Wall performance affects EPC ratings and resale potential

If you’re planning to sell, insulate, renovate, or improve energy efficiency, understanding your wall construction is the first step.