Understanding Subsidence: The Role of an RICS Surveyor in Diagnosing and Managing Property Risk
Subsidence, the gradual sinking of the ground causing a building’s foundations to shift or collapse, is a serious concern for property owners. It can lead to significant structural damage and decrease the value of a property. Recognizing the signs of subsidence and understanding the role of an RICS (Royal Institution of Chartered Surveyors) surveyor in diagnosing and managing this risk is crucial for maintaining the safety and integrity of your property. This blog post delves into what subsidence is, how it’s identified, and the critical role RICS surveyors play in this process.
What is Subsidence?
Subsidence is most commonly caused by changes in the soil beneath a building’s foundations. Several factors can contribute to these changes:
- Clay shrinkage: This occurs when clay-heavy soil loses moisture, often due to prolonged dry spells, leading to soil contraction.
- Water leakage: Broken pipes can wash away or soften soil, removing the support for building foundations.
- Tree root growth: Large trees near buildings can absorb significant amounts of water from the soil, causing it to shrink.
- Previous mining activities: Old mines can collapse, causing the ground above them to sink.
Signs of Subsidence
The symptoms of subsidence can vary, but common signs include:
- Cracks in walls, floors, or ceilings, particularly those that are diagonal and wider at the top.
- Doors and windows becoming stuck or difficult to open.
- Visible sinking of the ground around the property.
- Extensions or conservatories separating slightly from the main structure.
The Role of an RICS Surveyor in Diagnosing Subsidence
When subsidence is suspected, an RICS surveyor plays an essential role in diagnosing the issue. Here’s what their role entails:
Detailed Property Assessment
An RICS surveyor conducts a thorough inspection of the property to assess any visible signs of damage and to determine potential causes of subsidence. This involves checking for cracks, measuring their size, and observing their pattern and location. The surveyor also looks for less obvious signs such as misaligned doors and windows.
Soil and Foundation Investigations
If subsidence is suspected, further investigations may be necessary. RICS surveyors often collaborate with geotechnical engineers to examine the soil characteristics around the foundations. This might involve digging test pits or using ground-penetrating radar to understand the soil composition and moisture content.
Providing Expert Advice
Based on their findings, RICS surveyors provide detailed reports to the property owner, outlining the severity of the subsidence and its potential causes. They offer expert advice on the next steps, which might include monitoring the cracks over time to see if they worsen or recommending more immediate interventions.
Long-Term Monitoring and Management
In cases where immediate repair isn’t necessary, an RICS surveyor might set up a monitoring period to track the development of structural changes. This allows for a better assessment of whether the subsidence is ongoing or has stabilized.
Remediation Solutions
For significant subsidence issues, surveyors can advise on remediation solutions. These might include underpinning the foundations (a process where the existing foundations are extended deeper so they rest on more stable soil), removing nearby large trees, or repairing leaking drains to address the cause of soil washout.
Is There a Specific Subsidence Survey?
There is no standalone “subsidence survey” in the RICS Home Survey range. Subsidence is identified inside a standard RICS Home Survey — a Level 2 (HomeBuyer) report will flag visible signs of movement, while a Level 3 (Building Survey) inspects the structure in far greater depth and is the one to book where movement is already suspected. If you have been told a property “needs a subsidence survey”, what you actually need is a Level 3 survey carried out by a chartered surveyor.
Depending on what the surveyor finds, the investigation can extend beyond the visual inspection. Level monitoring can establish whether a floor or wall is genuinely out of true, and a drain survey is often used to rule out a leaking drain washing soil away from the foundations. Where the evidence points to active structural movement, the surveyor will normally recommend a structural engineer’s report as the next step — that report, not the home survey, is what an insurer or lender will ask to see. The RICS consumer guide to subsidence sets out the same route.
Not sure which level you need? Our guide to RICS Level 2 vs Level 3 surveys walks through the difference, and what subsidence is and how it affects your property covers the causes and warning signs in more detail.
Booking a Subsidence Survey in Derby and the East Midlands
WR Surveying are RICS-registered chartered surveyors covering Derby, Derbyshire, Nottinghamshire, Leicestershire and Staffordshire. If you have spotted diagonal cracking, sticking doors or windows, or a bay or extension that appears to be pulling away, a Level 3 Building Survey will tell you whether the movement is historic and stable or ongoing and in need of action — and what the sensible next step is before you commit to a purchase. Get in touch for a quote and we will tell you honestly which level of survey the property warrants.
Conclusion
The expertise of an RICS surveyor is invaluable when dealing with subsidence. Their ability to accurately diagnose the issue, assess risks, and advise on appropriate remedial actions helps property owners manage potential damage effectively and maintain the safety and value of their property. If you suspect subsidence in your property, consulting with an accredited RICS surveyor should be your first step towards finding a solution. Their professional assessment ensures you have all the information necessary to make informed decisions about how to best protect and repair your property.