Basement works, exceptional basements at fixed prices in the London Area

We typically design a basement to have at least 2.7 metres of finished headroom, more than your average London basement company would typically propose. We feel it is important to preserve the perspective of room size and height from the existing floors above so the new space doesn’t appear confined in comparison.

If you have a period house, it is also likely you will have a step down to the rear part of the ground floor. We will ensure this step does not continue in the basement floor, giving you more flexibility with room layout and providing even more headroom at the front of the property.

Waterproofing technology has come on leaps and bounds since the early cementious tanking systems were used to 'block out' the natural passage of water. Most modern conversions use a plastic cavity membrane system that allows the moisture to run uninterrupted behind the membrane into a sump beneath the floor, which is then pumped away into the drainage system. This means that no differential pressure is created either in the structure or across the membrane, and also that a vapour barrier as well as a water barrier is created between the earth and the structure.

For large structural projects detailed plans and specifications are a must as these enable us to provide accurate timescales and costs. They are also required for planning permission and for the engineer to work from.

Planning permission is usually required for large structural alterations or additions to existing buildings, and the erection of new buildings. Planning permission is not required for all types of works, as some works are classed as 'permitted development'. In the first instance, your council planning officer will be able to advise you as to which controls your work will be subject to. If we are contracted to undertake all pre-works arrangements for you, we will look after these issues and obtain all relevant permissions on your behalf.

If your house is more than 170 years old or of special architectural or historical significance it may be Listed which means you will also require Listed Building Consent in order to carry out works. Such buildings are described as being either Grade I, Grade II* or Grade II in significance. This Listing potentially covers both the external and internal aspects of the structure. We will be able to advise you and seek the relevant permissions on your behalf. OLBC has expertise in these areas and we are a particularly good choice for your project if you have any specific concerns with regard to the safeguarding of any material of your property, or require any advice on sensitive restoration or conservation work.

If you have not already commissioned plans or engineering, we would encourage you to come direct to us for the entire ‘pre-works’ package. Not only can we offer you a cost-effective end-to-end service, we can free you of the responsibility of introducing professionals who may not have worked together before and may not share the same working approach. With our complete service the responsibility for delivering your project to site rests with our professionals who are experienced at working together to arrange basement excavation projects.

The 'pre-works' element which is necessary to complete before work begins onsite will generally take from 3 to 4 months. In this time, we need to survey the site, agree plans for the basis of the new basement space, create a full quotation and specification, acquire planning permission, engineering, Party Wall awards, apply for street license and notify Building Control.

When on site the basic rule of thumb is to allow 16 weeks in the digging phase and around the same again for the structural and complete fit-out. There are many factors that can influence this average timescale, and you will be kept fully informed both before and during the project as to the timescale.

If you are just excavating a basement in a house with suspended timber floors in most cases it is feasible to live in the house. If we are undertaking works beyond the basement, we usually recommend that the client vacate the premises. This has a positive effect on coat and duration, and is much nicer for the client. If we are only working underneath the house, it is highly likely that we can work with you in place. In this case we will seal any gaps in your ground floor to minimise the occurrence of dust, and keep all work areas screened off with our hoardings. Any work noise will be limited to our normal working hours. It would be unrealistic to suggest you wouldn’t notice we were there, but you should be able to continue using your ground floor as usual so disturbance should be minimal.