Plan a Basement Extension- A Step by Step Guide

A basement extension is a great way of utilising hidden but currently unused or ignored spaces.

Many properties have a ‘basic’ basement so one of the first things to establish is whether you need to add to this in terms of size, convert it for a different use, or both. Alternatively, basements can be created from scratch, provided that there is scope for significant excavation and underpinning of walls. Which one of these you are going for will significantly affect the cost and scope of the project.

For the purposes of this guide, we will assume there is an existing basement and that you want to convert it into a useable space and may want to make it bigger.

Step 1 – Carry out a viability study

You should look at the following things:

– Access levels for builders/contractors/deliveries
– Disruption/noise impact on neighbours
– Structural state of the existing property
– Planning permission requirements (if any)
– Local ground conditions and soil types
– Drainage characteristics and flood danger/history
– How flat or otherwise is the existing basement floor
– Ventilation needs
– Fire escape/building regulation requirements
– Plumbing and electrics.

It may take some time to collect all the relevant information but it is worth doing before getting too far into the project.

Step 2 – Assuming the project remains viable, create a basic brief

This brief should include:

– What you want to use the new space for. It could be a home gym, a library, a home theatre room, or even a bar
– How big do you need the space to be? Is the existing space sufficient or do you want to add to it by, perhaps, extending under the garden
– How do you want to get in/out? Do you need a new staircase or external access?
– Does the floor need to be dropped to increase headroom?
– How much natural light do you need? What type of windows or skylights would be most useful?
– Is it important that the extension/conversion adds significant value to the property? If so, then bear in mind that a high-spec, well-lit, habitable basement space with its own access points will add more value than a simple converted cellar that is still dark and damp with low headroom.

Having this brief will make it easier for you to explain your requirements to the professionals.

Step 3 – Find an expert

Assuming that this project is too large for you to do yourself, you might at this stage wish to approach a company that specialises in basement conversions/extensions.

Expert basement specialist in London

basement specialist in London will be able to guide you through the process and also provide a wealth of experience and expertise. Why not contact an ASUC registered basement specialist in London, such as Noble Structures, today? As a specialist, we know how much these projects typically cost and how common they are in your area. As a leading basement specialist in London, we will also utilise local tradespeople and contractors with whom we have worked before.