Subsidence – Warning Signs When Buying a House

Subsidence is one of the most common concerns raised by property buyers. While not every crack indicates a structural problem, it is important to understand the warning signs that may suggest movement within a building.

As a Chartered Surveyor and RICS Registered Valuer, I regularly inspect properties where buyers are worried about possible subsidence. In many cases the movement is historic or cosmetic, but occasionally further investigation is required.

What is Subsidence?

Subsidence occurs when the ground beneath a building moves or compresses causing the foundations to shift. This movement can lead to structural cracking or distortion of the property.

Subsidence can be caused by a range of factors including clay soils shrinking during dry weather, leaking drains, factors extracting moisture from the soil or poorly constructed foundations.

Common Signs of Subsidence

Some of the most common indicators of possible subsidence include:

• Diagonal cracks around doors or windows
• Cracks in walls that are serious
• Doors or windows sticking or not closing properly
• Sloping floors or distorted walls
• External cracks in brickwork
• Cracks that are wider at the top than the bottom

However it is important to remember that not all cracks indicate structural movement. Many cracks are caused by normal thermal movement, differential movement, minor settlement, etc.

Properties More Susceptible to Subsidence

Certain types of properties may be more prone to subsidence including:

• Victorian and Edwardian houses with shallow foundations
• Properties built on clay soils
• Houses located near factors with potential to cause ground movement including trees
• Properties where drainage issues are present

In areas such as Dorset and Hampshire, clay soils can expand and contract significantly depending on moisture levels which may result in seasonal movement.

When Should You Obtain a Property Survey?

If you are buying a property and notice cracks or other signs of possible movement, it is advisable to obtain a professional survey before proceeding with the purchase.

A RICS Level 2 Home Survey can identify visible structural concerns and highlight whether further investigation may be required.

For older or altered properties a more detailed RICS Building Survey may be recommended.

Learn more about RICS Level 2 Home Surveys
Learn more about RICS Building Surveys

Professional Advice from a Chartered Surveyor

A professional survey helps property buyers understand the condition of a building before purchase and can identify potential structural issues such as subsidence, dampness or structural defects.

Castle Surveyors are independent RICS Chartered Surveyors providing property surveys and valuations across Dorset and Hampshire including Bournemouth, Poole, southampton, Verwood, Ringwood, Wimborne, Hedge End, Romsey, Lyndhurst, Hythe, New Milton, Highcliffe on Sea, Ferndown, Southbourne, Totton, Christchurch and the New Forest.

Call 0800 246 1002 for advice about a property survey before purchasing a home.