Let me say at the outset, this is going to cost money. There will inevitably be a serious excess, so you will have to pay the initial part of a claim. The majority of UK house insurance policies now impose a ?1,000 excess but you might shop around for less. It's best to have some money put to one side!
Second, your claim is very likely to take many months to complete. There is a substantial list of exclusions. Here is a typical list. If one or more of these apply, you might well be without any help from the insurance company.
No outside walls, patios, decks, terraces, gates, paths, drives etc. are covered if none of your main buildings or outbuildings are damaged.
Subsidence as a result of coastal erosion.
Any disturbance of solid floor slabs unless the house's foundations under exterior walls are also damaged by the same cause
Bedding down of newly erected buildings or newly made-up ground settling.
Thankfully there are the extras that are included in standard cover. This is where you actually get some cover against accidental damage with your standard perils.
Underground service pipes and cables. Apart from wear and tear, you are pretty well covered for any damage you are responsible for as the property owner.
Glass and sanitary fittings. Again you are covered against accidental damage to your built in ceramic hobs, bathroom fixtures and all windows in the building. Beware, that there is a clause further on into the policy that will restrict what you are allowed to claim for. Each item is treated as an individual item, not as part of a set. Thus, if your wash basin is accidentally damaged, don't expect the company to pay out for a complete new bathroom suite!
Stand-By Accommodation. This can be a very important benefit if it becomes dangerous or impossible to stay in your home. The insurance company will pay for alternative accommodation. This might be a local hotel or maybe the extra costs to friends and family if they can give you a roof over your head. At least one major online insurance company will also pay for your pets to go into boarding kennels if necessary. Cover might also offer either payment of rent or loss of rent due if you are a landlord. There is a limit, a sum insured which is normally around 20% of the total value of the property as specified in the policy.
By the way, if you sell your property, the person who buys it can enjoy the benefit of the cover up to the completion date provided they have no policy of their own in force at the time.
BASIS OF SETTLEMENT - All good policies will offer 'reinstatement'. That is, in effect, 'new for old'. The property will be repaired with new materials and should the entire structure be beyond economical repair, it will be rebuilt using new materials and no contribution from you (except any excess). The latest building regulations might mean increased rebuilding expenses. Sadly, if only part of the building is damaged and restored, the remainder of the building might then come under new building regs and this expense would be down to you. Demolishing, debris removal, shoring up and so on will all be covered as are reasonable architects and surveyors fees, legal costs and fees for plans, estimates and so on.
In all instances the insurance companies like to be in control of the matter so if you notice cracks in your home, report it to them immediately. If you go and instruct your own surveyor they might well recommend drastic measures to prop up your house that might not be required. You would find yourself in dispute with the insurance company.
There are many issues that will arise following a subsidence claim. Owing to the length of time that these claims can take, things such as trying to sell your home, trying to change your insurer and so on can all raise problems. It would take a whole volume to answer them all. One that is worth mentioning is that if you have changed insurance companies, the previous insurers might be required to contribute to your claim under the A.B.I. Domestic Subsidence Agreement. This prevents disputes between insurers as to who pays for what. It should not affect you at all.
We'll finish by considering what happens when an underground pipe has leaked and this has led to movement and thus subsidence? What insured peril should apply and what excess will you have to pay? It is in your interests to show that the claim should be dealt with by the the underground services peril. That way you do not have to pay the large excess of a subsidence claim. It is all down to what insurers call the 'proximate cause'. You need to be able to show that the proximate cause of the subsidence is the leaking or broken pipe.