Blogs
Can a Level 3 RICS Survey Confirm If Underpinning Has Stopped Movement?
Wednesday 8th January 2025
Carl O'Boyle BSc MRICS FCIOB MFPWS
Yes, it is expected that a Level 3 RICS Building Survey (previously known as a full structural survey) should confidently report on a property that has been underpinned due to past subsidence, provided the surveyor has access to the necessary information and carries out a thorough inspection. However, confirming the long-term stability of an underpinned property involves specific steps and considerations.
How a Surveyor Can Confirm the Condition of an Underpinned Property:
1. Visual Inspection
The surveyor will perform a detailed visual inspection of the property, looking for:
• Signs of ongoing movement, such as new or widening cracks in walls, ceilings, or floors.
• Misaligned features, like doors or windows that stick or no longer close properly.
• Distortions in structure, such as uneven floors or leaning walls.
2. Review of Documentation
The surveyor should request and review all relevant documentation related to the underpinning works, including:
• Structural engineer’s reports that detail the original cause of subsidence.
• Details of the underpinning method used (e.g., traditional mass concrete underpinning, piled underpinning, or resin injection).
• Completion certificates or warranties from the contractor or structural engineer confirming the works were carried out to an appropriate standard.
• Insurance claims or documentation if the underpinning was part of an insured event.
3. Checking the Property’s History
The surveyor may look into:
• Planning permissions or building control approvals for the underpinning work.
• Local authority records to check for known ground issues in the area (e.g., shrinkable clay soil, mining activity).
4. Monitoring for Movement
If there are concerns about ongoing movement, the surveyor may recommend:
• Crack monitoring over a period (usually 6-12 months) using tell-tale gauges or professional monitoring equipment.
• This helps determine if cracks are stable or if further movement is occurring.
5. Soil Investigations
In some cases, the surveyor may suggest:
• Soil analysis to confirm the type of ground beneath the property and assess the likelihood of future movement.
• This is especially important in areas prone to shrinkable clay or with a history of subsidence.
6. Specialist Input
If the surveyor cannot confidently conclude that the property is stable, they may recommend:
• A structural engineer’s inspection to provide a more in-depth analysis.
• The structural engineer can carry out more detailed investigations, including potential load testing or structural monitoring.
What the Level 3 Report Should Include:
• Clearly state whether there are any signs of ongoing movement.
• Provide a professional opinion on the adequacy of the underpinning based on the available documentation and inspection.
• Highlight any limitations of the survey, such as inaccessible areas or missing documentation.
• Recommend any further investigations if necessary.
• Include guidance on future maintenance, especially if the property is on shrinkable clay soil.
Key Considerations for Buyers:
Even if the underpinning appears to be effective and the property is stable:
• Insurance: Ensure that the property is insurable, as some insurers are hesitant to cover properties with a history of subsidence, even if they’ve been underpinned.
• Future resale: Be aware that a history of underpinning may affect future marketability, and you may need to provide potential buyers with clear evidence of stability.
Conclusion
A Level 3 RICS survey can confidently report on an underpinned property if the surveyor conducts a thorough inspection, reviews relevant documentation, and finds no evidence of ongoing movement. However, if critical information is missing or there are concerns about stability, the surveyor should recommend further investigations by a structural engineer.
