Buying a property with a history of subsidence

If there’s one word that strikes fear into homebuyers up and down the country, it’s subsidence. But what exactly does this mean, and is it wise to proceed with the purchase of an afflicted property?

But let’s go back a step first. Before you go ahead with the purchase of any property, we highly recommend that you have an independent survey carried out to alert you of any problems with the building. After all, you are about to make a major financial commitment and need to know that your investment is safe. A survey should be part of your due diligence process, empowering you to make the right decision based on all the necessary factual information. You know what they say – better safe than sorry. Here’s an informative blog we recently wrote on that exact topic.

At Cosey Homes, we have a highly skilled team of Chartered Surveyors, structural engineers and building engineers at our disposal who conduct a range of property surveys to identify serious building defects, and that includes structural movement. If subsidence is suspected, our specific structural inspections can be used to further investigate and clarify the seriousness of the issue and provide specialist professional building advice.

What is subsidence?

In basic terms, we talk of subsidence when the ground on which a building stands begins to sink. When the soil beneath the foundations becomes weak and unable to support the building properly, a downward movement can occur. This can lead to structural damage that can jeopardise the integrity of the entire building. In the worst-case scenario, the structure could ultimately collapse.

In practice, subsidence issues can be dealt with effectively with professional intervention, especially if the signs are spotted early enough.

What causes the ground to become unstable?

There are several known factors that may cause subsidence. The moisture content of the soil plays a major part in this. Clay-rich soil, for example, naturally swells in the winter when the weather is wet and shrink in the summer when the weather is drier. Gravel and sand, on the other hand, may be washed away as a result of long periods of wet weather or long-term damage to pipes underground. Both shifts can affect the integrity of the building on top.

Moisture levels in the ground are also affected by trees and shrubs. They naturally absorb water through their roots, leaving the soil drier and thus more susceptible to shrinkage. Clay soils are particularly affected, especially in combination with ‘thirsty’ trees such as willow, oak, poplar or elm trees. These types of trees should always be planted at a safe distance from the building, and preferably not at all in a normal sized garden. By way of example, a mature willow tree draws 220-450 litres of water per day from the ground around it. No wonder that the minimum recommended distance from the house is 40 metres.

Other causes of subsidence can include construction work close to the house, leaking underground pipework, ongoing traffic vibrations and a history of mining in the area.

How do you detect subsidence?

As already mentioned above, the sooner subsidence is diagnosed in a building, the easier it is to remedy the problem. Classic tell-tale signs of structural movement to look out for are cracks in walls or ceilings that appear suddenly:

• Cracks that are wider than harmless surface cracks (approx. > 3mm)
• Cracks around window and doors, or at the joint between the main building and a newer extension
• Cracks that run diagonally down the wall, being wider at the top than at the bottom
• Cracks that are visible both on internal and external walls
• Uneven floors and skirting boards with gaps underneath

For more information about cracks in walls, take a look at this recent blog post.

At Cosey Homes, our experienced surveyors know how to tell the difference between settlement cracks that are perfectly normal and harmless, and cracks that are an indication of structural movement having occurred. Our professional observations and recommendations for action will be clearly documented in your survey report.

Should you buy a house afflicted by subsidence?

The big question is what to do when the property you have your heart set on turns out to have subsidence issues, either past or present. Should you buy it regardless, and if so at what price? Should you run a mile the other way? Ultimately, only you can make that decision, but we are here to support you with all the relevant factual information and our professional advice to enable you to act with confidence.

With that in mind, we recommend the following course of action:

• A full RICS Building Survey should be conducted to identify the nature and severity of any structure issues with the property you are thinking of buying. The survey report will include our recommendations for remedial actions and cost estimates.
• Consult your mortgage lender as soon as possible. Lending criteria vary between providers, and while some may be satisfied with additional checks, others may refuse to lend on properties with a history of subsidence altogether.
• Obtain clear written evidence from the seller that any history subsidence issues have been resolved, including details of work carried out (monitoring, underpinning etc) and when the work was completed.
• Look into home insurance cover for properties with a history of subsidence. Most standard home insurers will charge much higher premiums for affected properties or reject them out of hand. Niche insurance providers do exist – do your homework.

Should you ask for a discount on the agreed price?

 The sale price agreed between the seller and buyer is always ‘subject to survey and contract’. Any new information emerging as a result of the survey that has a material impact on the value of the property will therefore have a bearing on the agreed price. If subsidence has been identified as an ongoing concern or past problem, there is little doubt that the value of the property will be affected as a result. As a buyer, you therefore have every right to approach the seller to review the situation.

This is where a RICS Building Survey can be worth its weight in gold. Armed with detailed professional advice about the structural condition of the property, you are in the best possible situation to make an informed decision, whether that decision is to do nothing and proceed with the purchase as planned, ask the seller to fix the problem before contracts are exchanged, renegotiate the purchase price, or pull out of the transaction altogether.

For friendly expert advice about your next property purchase, or to discuss your surveying requirements with our team and obtain an instant survey quote, please contact Cosey Homes today.