It lacks the excitement of looking at plans or the satisfaction of designing your new living space, but arranging insurance is one of the bread-and-butter jobs you need to have sorted out before signing up with the contractor for your basement conversion.

Obviously, you need to be insured during the building work phase, so the first job is to phone your insurer and tell them what you are planning. Bear in mind that the insurer doesn’t insure your building – they insure the risk of something happening to your building. This subtle but crucial difference means that as soon as you start doing any work on the structure, many insurers suspend the insurance. The current insurer will want to know all the details of the project, including plans, costs and timescale, and will want to be assured that the company you are using specialises in this kind of work and is properly insured themselves.

If Your Regular Insurer Says No

Don’t, under any circumstances, be tempted to wing it. Don’t forget it’s not just your house – if there is any problem with a neighbour’s property and they decide, rightly or wrongly, that it’s your fault, then they may bring a claim against you.

If you are using a professional basement conversion company, they will be able to point you in the direction of brokers who can arrange cover for the duration of the works, which will insure you against all the risks that might arise.

A reputable company about to start a basement conversion in London will have public liability insurance – this covers them if they accidentally cause injury or damage to a third party, such as a neighbour. They should be willing to supply proof of this as part of the contract documentation. Surveyors, architects and others working on the project need professional indemnity insurance – this covers them against design faults or other errors.

And don’t be tempted to skimp on the amount you are covered for. Think of the worst possible scenario and get cover for it.

JCT Contracts

Your contractor may have their own insurance covering both themselves and the building during the works, up to the point they complete the job and hand the gleaming new basement over to you. However, if you are using the standard JCT building contract, you may find that it requires you and the main contractor to be jointly insured.

Party Wall Insurance

With basement conversions, many people consider taking out specific insurance for the party wall, although a comprehensive building project policy may include this already. This type of insurance specifically insures against damage to a neighbour’s property caused by work affecting the party wall.

If you have a neighbour who is very worried about your conversion and the effect on their property, they may feel less anxious if they know that you are full insured against any adverse effects and are using a reputable company that is similarly covered.