Converting or Creating a Basement? Here’s the Steps Involved

If you’re looking to extend your home, and building outwards or upwards isn’t an option, some homeowners may look downwards for that all important extra space.  If you’re lucky enough to have an existing basement or cellar then there will be fewer obstacles than for those starting from scratch, but all the same it’s a sound investment in terms of adding value and space to your property.

Below are some of the typical steps to follow if you’re thinking of embarking on a basement project.


Speak to an architectural specialist and discuss your wishes for the project.  You’ll be given indications of both costs involved and time scale for completion, and then a formal quote for the structural and finishing aspects of the job.

Plans and Design

A full survey of the property will need to be carried out, and designs for the proposed build will be created.  When you agree a design, you will need to apply for planning permission which can take anything up to eight weeks to be approved.  Meanwhile your architect or builder (a specialist in basements is best) will arrange a Party Wall surveyor to approach the neighbouring properties in order to achieve a Party Wall award.  Once these are obtained your builders will have a clearer idea of timeframe for each phase of the build. A suitable renovation insurance policy should be purchased in order to cover every eventuality.

The Build

If excavation is required this will be done by digging and removing the soil beneath the property with underpinning work carried out by adding reinforced concrete, timber or steel beams to support the structure of the house above, all under the guidance of a structural engineer.  The structure will be waterproofed and any manholes and drains will be relocated.

The Finish

The fit-out of your new basement will involve all the trades!  Electrics, plumbing, carpentry and joinery will all have to be carried out in accordance with Building regulations. Once all of this has been signed off, you can have a builders clean carried out and get ready for choosing your colour scheme!  After that, just add furniture!