In building terms subsidence is uneven downwards movement of a structure’s foundation. In the South East and London regions most subsidence problems are caused by either tree root exacerbated clay shrinkage or a leaking drain or sometimes even a combination of both. Over 75% of subsidence insurance claims in the South East and London involve tree root exacerbated clay shrinkage.

If you believe your property is suffering from subsidence but you are unsure, some of your options going forward are explained below.

How can Hamblin Sullivan Associates help?

At Hamblin Sullivan Associates we have unrivalled experience in this specialised field of surveying and engineering having inspected thousands of properties with subsidence related problems. We have also been involved in subsidence diagnosis from both sides of the fence having worked for the major loss adjusting firms and as directly appointed external consultants. We are also often called upon by the insurance industry and other surveying/engineering firms for advice in this specialist field.

In over 80% of cases, due to our experience in this field, we are able to diagnose the cause of the damage without the use of time consuming and expensive site investigations and, in our experience, in the vast majority of cases the cause of the damage is not subsidence. Correct diagnosis at the beginning is extremely important as a misdiagnosis of subsidence could blight your property for years. Quite often where subsidence is the probable cause of the damage we can even recommend appropriate mitigation measures and repairs so you avoid having to make a subsidence insurance claim. This is particularly beneficial when the cause is straightforward and the damage is fairly slight i.e. up to 5mm cracks. We only charge a single fee regardless of our recommendation so our advice is always completely unbiased. When the cause is not directly related to subsidence we will also confirm the cause of the damage and recommend an appropriate repair.

If you have already submitted a subsidence claim and you have concerns about the loss adjuster’s diagnosis or how the claim is progressing then contact us and for a single fee we can provide an Independent Engineering Appraisal Report to offer a second opinion.

Also if you are not sure about the repairs that are being proposed to your property or are not satisfied with how the works are progressing then our specialist surveyors can take the stress away from you and project manage the works on your behalf through to completion. We will liaise with the loss adjuster for you and our fees should be covered under the terms of your policy.

We are also party wall specialists so if your claim involves party wall works and you would prefer to appoint an independent party wall surveyor or if your neighbour would like advice on the party wall process then feel free to contact us.


Heave is the opposite of subsidence – the upwards movement of a foundation. This is quite rare and usually occurs where clay soils below foundations rehydrate ‘swell’ following the removal of a nearby tree. Depending on the extent of the heave underpinning may sometimes be necessary. Should you suspect your property is suffering from heave we can also advise you in this respect as well. Your options in this respect are similar to those described above in relation to subsidence.

We will be pleased to discuss your concerns and requirements over the phone before we are formally instructed and should you decide to instruct us we will usually provide you with an emailed copy of the report within 24hrs of the inspection.

We hope we can be of assistance.

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