Basement Conversions FAQs

Do I need an existing basement?

No! We can convert existing basements into habitable spaces, but the majority of our work involves excavating and building the basement itself. We have extensive experience doing this, and offer a range of guarantees on our work and materials.

Can I still live in the house while building the conversion?

Yes – your house will still be habitable and other than a little noise and the exterior covers, there will be no changes to your living arrangements at all.

Will the basement be damp?

No – we install membranes and completely tank your basement to ensure that it’s dry and comfortable. We may need to install a water pump to keep it dry and prevent water ingress.

Will the basement be dark?

No – we add a range of natural lighting options including light wells, light tunnels, and windows. These let natural light into the basement so it feels like any other room in the house.

Do I need planning permission for a basement conversion?

In almost all instances, you will need to gain planning permission. We partner with a number of RIBA qualified architects to help you with designs and submit your planning application.



Will I need a party wall agreement?

In most instances, yes. This helps to protect you and your neighbours in case of accidental damage, and outlines the expectations so your neighbours know exactly what is happening.

Can the basement conversion be built beyond the footprint of the house?

Yes. While it’s subject to planning permission and other restrictions, we may be able to build beyond the footprint of the house and extend into your garden to create a larger basement.

How long does it take to build a basement conversion?

The duration of the project depends on the type of conversion, type of ground, and complexity of the project. Most conversions are completed in around 12-40 weeks, but our team will provide you with a definite schedule when they have completed the plans and necessary surveys.

ANY QUESTIONS? CALL 020 3174 1241
Case Studies

Loft Conversions Add a Fifth to Property Values

Loft conversions are one of the best ways to make your home more spacious – an intelligently-designed conversion can add as much as 30% more living space to your home without extending the footprint of your house. As with all home improvements, conversions also increase the value and sale-ability of your home. A study by […]

quote mark

The client wanted to make extensive improvements to her home in Wandsworth, including a loft conversion, a kitchen extension, and alterations to her existing lounge and one of the existing bedrooms. All of the work took around 12 weeks and they were extremely happy with the results.  


Avian Construction Ltd

Peterden House
1A Leighton Rd
West Ealing
W13 9EL

020 3174 1241