Extensions, Basement and Cellar Conversion Specialists

General Building & Extensions
New & Existing Basement & Cellar Conversions.
Waterproofing, Underpinning & Surveys
Serving Cheltenham, Gloucester, Cotswolds, Gloucestershire, Bristol & the South West.

Our Services

Here's what we can do for you


We don’t just build down but can also create a fantastic extension to your home.

John Newton Products

A market leader for damp proofing and structural waterproofing solutions.

New Build Basements

Dig down to create a great new living area suitable for a variety of uses.


Strengthen unsafe foundations to support further building or to combat subsidence.

Basement Conversions

Convert that damp, dusty cellar into a vibrant living space.

Survey Service

At CellarTech we offer a full survey service helping to identify and issues or problems.

Why CellarTech?

If you live in the Gloucestershire area and are considering a new basement or cellar, converting or extending an existing basement, underpinning work or an extension of any description, then you should be talking to Cellar Tech!

Over the years we have built an excellent reputation in the local community and industry at large for providing the highest quality work, quickly and efficiently and at a competitive price. Unlike many firms we undertake to deal with every part of the job for you, from the initial planning and survey, through project management and construction to the final decorating and clean up.

All our work and the materials we use are backed by a 30 year guarantee. In addition we use John Newton waterproof membranes, recognised as the best in the industry. If you need convincing of the quality of our work take a look at our Gallery and read some of our Testimonials.

Whether you are considering a new or converted basement, need underpinning or want an extension, give us a call on 01452 619871 or 07718 793967 to find out how we can help you.

About Us

Our Work

Areas We Cover

Our Testimonials

We have used Cellartech on many occasions now to help us with below ground solutions. From the design stages through to the installation Ian and his team have done a great job. Do not hesitate to contact Cellartech if you are after a new installation or have an existing issue with damp.

Mr Jason G

Site Manager, GTB Homes Limited

Ian and his team were a hard-working, experienced, friendly bunch.  They always turned up on time, worked hard and left the site cleaned up at the end of the day.  Ian worked hard to ensure that the build kept within our timescales and amazingly pretty much within budget.  Our experience went very smoothly with no major issues, but if we had any issues or questions Ian was always on hand to offer his advice and come up with a solution.  Ian even helped us to set up a temporary kitchen for use while the build was taking place (complete with old sink and running water!).  We’re really pleased with our finished extension and would definitely recommend Cellartech as a reliable, competitive building company.

Bobbie D

Ian is hard working, efficient, reliable and a tidy worker. He has completed work for us on many occasions and we have never been disappointed. His work ethic is second to none and we would highly recommend him.

Mr Malcolm W

Contact Us

We welcome any enquiry - small or large.

01452 619871
07718 793967


The Black Containers, Rear of Bullens Manor Farm, High Street, Upton St Leonards, Gloucester GL4 8DL

Contact Us