Subsidence, cracks and the bigger picture: What I’m seeing on the ground

Inspired by a Financial Times article by Anna Tyzack.

From properties requiring underpinning to cracked finishes, mature trees and hidden leasehold liabilities, why good property due diligence starts before the survey.

A recent article in the Financial Times, Is Britain sliding into a subsidence crisis?, brought into focus an issue that has increasingly caught my attention during property searches with clients.

I am encountering properties marketed on a cash-only basis because of subsidence concerns, sometimes with survey reports, structural assessments and estimates for underpinning already available from the selling agent. I am also seeing cracks and other signs of possible movement in properties of very different ages and types.

Of the ten properties I viewed with clients during the past couple of weeks, two required underpinning, while another two had visible cracking that I would have wanted investigated further.

That is a snapshot of my own experience, not a representative survey of the London property market. Nor does cracking automatically indicate subsidence. But it illustrates why I believe buyers need to look beyond a property's presentation and ask the right questions before committing their money.

For me, this is about more than spotting a potential defect. It is about understanding the property, its surroundings, its responsibilities and the financial implications of what might be discovered.

Why subsidence deserves attention

Subsidence occurs when the ground beneath a building moves downwards, potentially causing its foundations to move and the structure above to distort.

In areas with shrinkable clay soils, prolonged dry weather can cause the ground to lose moisture and contract. Trees and large shrubs can contribute by drawing water from the soil. Defective drains and other ground conditions can also play a part.

London and the Southeast contain extensive areas of clay-rich ground and many older properties with foundations that may be more vulnerable to changes in ground conditions. However, being built on London clay does not, by itself, mean a property has a subsidence problem. The foundations, soil, drainage, vegetation, building history and evidence of actual movement all matter.

The financial implications are becoming harder to ignore. According to the Association of British Insurers (ABI), domestic subsidence payouts reached a record £307 million in 2025, up 10% on the previous year.

The ABI subsequently reported that insurers paid £72 million in domestic subsidence claims during the second quarter of 2026, with the average claim reaching a record £20,000.

These figures underline the scale of the financial exposure. They do not mean that every property with a crack is suffering from subsidence, or that every home on clay is at imminent risk.

Sources: ABI, 2025 property insurance payouts and ABI, subsidence claims in the second quarter of 2026.

What does “cash-only” really mean?

When a property is marketed as cash-only, I want to understand precisely why.

A mortgage lender may be unwilling to lend until further investigations or remedial works have been completed. Suitable buildings insurance may be difficult to obtain, or the property's history may create complications for a future buyer.

Reports and estimates supplied by the selling agent can be useful starting points. But they are not a substitute for independent advice tailored to the buyer's circumstances.

I would want to understand what the original problem was, whether its cause has been established, what investigations have been undertaken, what remedial work has been completed and whether there is evidence that the solution has been effective.

There is an important distinction between historic movement that has been properly investigated and addressed and a property where the cause remains uncertain or movement may be continuing.

The distinction can affect far more than the purchase price. It may influence mortgage availability, insurance terms, future maintenance costs, the time required to complete a purchase and the property's eventual resale prospects.

A discounted property is not necessarily a bargain if the discount fails to reflect the cost, uncertainty and risk involved. Equally, a property with a known and properly managed issue should not automatically be dismissed.

The objective is to establish what is known, what remains uncertain and what that means for the decision to buy.

Even a new-build deserves scrutiny

One property I viewed recently was an architecturally designed new-build with an impressive specification: an A-rated EPC, triple glazing, solar panels and a mechanical ventilation with heat recovery system.

On paper, it had much to recommend it. Yet there were details I felt warranted closer examination.

The house extended over three floors and had resin-poured flooring on both the ground and top floors. The ground-floor finish was visibly cracked in several places, to the point where it detracted from the appearance of the room. Similar cracking was present upstairs, alongside noticeable cracks in sections of the external render.

These observations do not, on their own, establish a structural problem. Cracking can have a range of causes, including the materials used, installation, the underlying substrate, drying or subsequent movement.

But I would not simply have accepted the finishes at face value.

Had my clients wished to proceed, I would have wanted to establish whether the cracking had been investigated, whether the flooring and render had been installed in accordance with the relevant specifications and whether any further assessment was warranted.

The lesson is straightforward: a modern design, excellent energy efficiency and advanced technology do not guarantee that every aspect of a building's construction or finish is performing as expected.

Every property deserves to be assessed on its actual condition, rather than its age, appearance or specification alone.

Trees, gardens and the clues beyond the building

On a viewing in Camberwell, I was reminded how important the surrounding environment can be.

The property was part of a development of four-storey Victorian-style homes on Camberwell Grove, one of the area's particularly desirable residential roads. Although the property itself was newly built, several front gardens contained large, established trees.

At the property I was viewing, the front boundary wall was split and cracked, the path was uneven and the tree was leaning.

I am not an arboricultural specialist and would not presume to diagnose the cause of the cracking or attribute it to the tree without further investigation. But the combination of a damaged wall, uneven paving and a substantial tree prompted several questions.

Who was responsible for maintaining the tree? Was there a regular maintenance programme? Had anyone investigated the condition of the wall and path? Were there any known drainage or ground-movement issues?

On shrinkable clay soils, certain trees can contribute to ground drying and increase the potential for movement. Roots can also affect paving, walls and drainage infrastructure. The significance of any particular tree depends on factors including its species, size, water demand, distance from the building, soil conditions and the foundations involved.

This is not an argument against trees. I am very much in favour of greener streets and better urban environments. It is an argument for thoughtful planting, suitable species selection and proper long-term management.

Nor is removing a tree automatically the answer. On shrinkable clay, the removal of an established tree can alter ground conditions as moisture levels recover. In some circumstances, the resulting expansion of the soil, known as heave, can affect foundations.

The appropriate response depends on the circumstances. Where there is a genuine concern, advice from suitably qualified arboricultural and structural professionals can help establish what is happening and what, if anything, needs to be done.

For a buyer, the point is to notice the wider context and ask the questions before it becomes their responsibility to resolve the problem.

The wider picture for leasehold buyers

A similar principle applies to leasehold properties.

I advised on a leasehold purchase within a larger development surrounded by mature trees. The trees contributed significantly to the character of the grounds, but I also considered their size and proximity to gardens and brick walls and the potential implications for maintenance over time.

If a tree requires specialist work, a boundary wall needs repair, or an investigation identifies a structural or drainage problem affecting communal areas, who pays?

The answer depends on the lease, the ownership and management arrangements, the nature of the work and the applicable service-charge provisions. Costs may be shared between leaseholders, but this should never be assumed without examining the relevant documents.

For a buyer, I would want to understand the maintenance responsibilities, review the available service-charge information and ask whether there is a known history of structural movement, drainage issues or significant expenditure on communal grounds.

This does not mean every development with mature trees carries a problem. It means that buying a flat involves assessing more than the four walls of the individual property.

The condition and financial health of the wider development can matter just as much as the condition of the flat itself.

My CLASP approach to property finding

These examples illustrate why I look beyond whether a property appeals to my client at first sight.

My CLASP approach provides a framework for assessing the property as a whole.

Condition - What is the visible condition of the building, its finishes, boundary walls, paths, drainage and surrounding structures? Are there cracks, distortion or other signs that warrant further investigation?

Location - What is happening in the wider street and neighbourhood? Consider ground conditions, mature trees, neighbouring buildings, the surrounding environment and the potential implications for maintenance and future ownership.

Attributes - Does the property have the features that genuinely matter to the client? That might include a south-facing garden, natural light, period character, outdoor space, privacy or a layout that works for everyday life.

Size - Is the property the right size, with sufficient living space, bedrooms, storage and garden or communal facilities for the client's needs, both now and in the foreseeable future?

Price - Does the asking price reflect the property's condition, its setting, any known risks and the potential cost of future maintenance or remedial work?

The order in which these factors matter will vary from client to client. But Condition and Price must be considered together.

A property may look attractive on paper, yet its apparent value can change considerably if further investigations reveal structural concerns, expensive communal repairs or unresolved maintenance responsibilities.

Equally, a potential issue does not automatically make a property a poor purchase. The question is whether the issue can be understood, investigated and properly accounted for in the buying decision.

Knowing when to bring in the experts

My role as an independent property consultant is not to diagnose subsidence, assess a tree's structural safety or replace the work of a building surveyor or structural engineer.

It is to help clients recognise when something warrants closer attention, understand why it matters and establish what needs to happen next.

Depending on the circumstances, that may mean commissioning a suitably qualified building surveyor, seeking a structural engineer's opinion, investigating potentially defective drains or obtaining advice from an arboricultural specialist.

These professionals have different roles. A building survey can identify defects and recommend further investigation. A structural engineer can assess particular structural concerns. A drainage investigation may help establish whether leaking or defective drains are contributing to ground problems. An arboricultural specialist can advise on a tree's condition and management.

The right appointment depends on the evidence and the questions that need answering.

Early investigation can help a buyer make a better-informed decision, whether that means proceeding, seeking further information, renegotiating or deciding that the uncertainty is too great.

It is far better to establish what is known and what remains unresolved before committing to a purchase than to discover afterwards that an important question was never asked.

Subsidence does not automatically mean underpinning

Underpinning is an established method of strengthening or extending foundations where the circumstances require it. But it is not the automatic answer to every case of ground movement.

Depending on the cause, soil conditions, building and foundations, specialist engineers may consider other approaches. These can include piling, ground improvement, localised stabilisation or other engineered remediation methods.

Some techniques may reduce excavation or disruption in suitable circumstances. Others may be inappropriate for a particular property. The choice should follow investigation and professional assessment, not a general assumption that one method is cheaper, quicker or better than another.

Tree management may also form part of a solution where vegetation is contributing to the problem, but it must be considered carefully because changing or removing vegetation can itself affect ground conditions.

For a prospective buyer, the important point is not to select a repair method from an article. It is to establish whether a problem exists, what is causing it, what options are appropriate and what the implications are for cost, insurance, finance and future ownership.

A concerning crack should prompt sensible investigation, not an automatic assumption that a property needs major structural work.

Buying well means seeing the whole picture

The recent reporting on subsidence is a useful reminder that property condition deserves serious attention, particularly in London and the Southeast.

But it is not a reason to become suspicious of every crack, every mature tree or every older property.

The real task is to distinguish an attractive home with manageable maintenance requirements from one where there are unanswered questions about its condition, surroundings or future costs.

Good due diligence starts before a formal survey is commissioned. It starts with observation, asking the right questions and understanding how the building fits into its wider environment.

That means looking at the garden as well as the kitchen, the boundary wall as well as the reception room and the communal grounds as well as the individual flat.

A property is more than the bricks and mortar within its boundaries. Its surroundings, responsibilities and long-term maintenance all form part of the buying decision.

At Adore Property, I help clients look beyond the obvious, ask better questions and make property decisions with greater clarity and confidence.

If you are considering buying a home and would value an experienced, independent perspective on its condition, location and longer-term implications, I would be pleased to discuss how I can help. Where a property needs technical investigation, I can help identify the questions that need answering and the appropriate specialist input.

If you are preparing to sell, understanding potential buyer concerns before marketing can also help you decide what to investigate, what to address and how best to present the property.

And if you need to sell one home while securing the next, my SYNCHRONISED-MOVE™ service brings both sides of the move together, helping you make coordinated decisions rather than treating the sale and purchase as unrelated transactions.

Good property decisions begin with good questions.

Please get in touch for a confidential conversation.