Simplifying the process

Why should I build a basement?
It is an effective way of gaining more space without the cost and hassle of moving home, and can add significant value to your property.

What can be achieved?
What is possible is determined by the amount of land that you have and your budget. We can extend an existing basement or create a completely new space. The new area is entirely waterproofed and with careful planning we will ensure that as much natural light as possible is allowed into the basement. We also design the basement with at least 2.4 metres of head height, which helps make it feel comfortable and spacious. The new space can be used for anything you choose. We have experience installing bedrooms, bathrooms, kitchens, utility rooms, sitting rooms, cinemas, game rooms, studies, wine cellars, gymnasia and even swimming pools. Most of the basements we build are single storey but we have successfully added up to three underground levels to houses and excavated down to 10 metres.

How much will it cost?
The cost will depend on your precise requirements and specifications. As a rule of thumb, structural costs are generally £1,700-£2,500 per m² and fit-out costs are around £750-£800 per m².

Will I need planning permission?
Most new basements, where the size of the new construction is significant and/or where there will be visual changes to the outside of the house, will require planning. If you have not employed an architect then we are happy to take you through the planning stage.

What about party wall awards?
If your building is next to or close to a boundary or party wall, then one or more party wall awards may be required. We can help negotiate this.

How long will it take?
Generally planning permission will be required and this will usually take 2-3 months to obtain. Following this, your decision on any other design points, and the processing of party wall agreements, work can commence on site. For the conversion of an existing small basement space, allow several weeks on site. For a large basement, allow six months on site.

How does a basement construction compare to a loft conversion?
Typically, loft conversions will be slightly cheaper than a basement construction in terms of the overall £/ft², however there are many advantages of basement conversions over loft conversions:

  • Your loft conversion is likely to be considerably smaller than the full potential of your basement construction(the basement can go under your whole home and even your garden, whereas the loft conversion is normally restricted to your current roof area).
  • Your basement conversion can have full ceiling heights throughout, whereas the loft conversion may suffer from sloping ceilings and you may lose some of the space to eaves.
  • For certain types of building, planning permission may be easier to achieve for basement conversions than for loft extensions as there may be less impact on the external appearance of the property.

Is there much disruption involved?
As with any construction work, there will be some noise and debris. This is reduced through covering of exposed areas and only working during normal office hours. Our ability to tunnel under the property means that you are able to remain in residence with minimum disruption.

Will the new basement be dry?
Yes. We use a drained cavity layer with a sump and pump system, which ensures that your basement remains dry.

Do I have a choice of fittings and finishes?
Yes. As part of the design phase we will endeavour to agree a specification for all of these items up-front. We have an in-house interior designer and experienced fit-out teams who will ensure that your new basement is exquisitely finished.

Can Basement Force assist with other types of construction?
Yes. Although our specific expertise lies in basement construction. We will consider other work, for example side return extensions and whole house refurbishments including a significant amount of underground work.

What assurances do I have?
All work is guaranteed by Basement Force. Additionally, as a member of ASUC, the Association of Specialist Underpinning Contractors, we can provide a 12-year insurance backed guarantee on all our work which can be passed to any subsequent owner of the property.