Our Services

basement suspended concrete slab supported through brackets to the waterproofed walls


We are an award-winning London basement conversions company with 35 years of experience. We build every type of basement from retrofit basements to new build basement construction. All basement conversions include a 10-year insurance-backed guarantee.

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Building Construction workers making a specialist cladding system with a drill


MJ Rooney offers a wide range of building construction services and will achieve the most technical and complex of building construction projects. Our building construction projects range between small local extensions and multi-million football stadiums.

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Civil Engineering project for grand designs with an engineer and a team of groundworkers building steel sheet piled temporary works.

Civil Engineering

MJ Rooney offers a wide range of Civil Engineering Projects from small local underpinning to large infrastructure schemes. We design and build our Civil Engineering Projects with cutting-edge technologies to deliver quality, speed and efficiency.

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About MJ Rooney

We are a family-run construction company that has been building London basement conversions and civil engineering projects for 35 years. MJ Rooney has an amazing team of in-house architects, engineers, and construction managers. We have the best team to deliver your basement conversions.

As members of ASUC and the PCA, we are regularly audited by independent experts to ensure we hit the highest technical, and health & safety standards. We make a computer 3D model and simulation of the build. This help us to solve design issues before we even start on site. It is also useful to sequence every London basement conversion project and civil engineering project perfectly.

MJ Rooney has won many construction awards like Construction News ‘Contractor of the year’, the CN “Digital Contractor of the Year” and Ground Engineering Contractor of the Year.

Our construction company specialist waterproofing in-house team will design and install it all wrapped up in a 10-year insurance-backed guarantee.

We deliver quality with a passion to every London basement conversion, building construction, and civil engineering project.


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Recent Case Studies

Permeable Car Parking and Roads.

Tunnelling below the City of London

Waterproofing Historic Prison.

"MJ Rooney is one of London's best Basement waterproofing Contractor. All of our basement waterproofing services are installed in-house with our highly trained basement waterproofing team. All basement waterproofing is designed by our CSSW surveyors with Professional Indemnity insurance. The basement waterproofing installation is also covered by 10-year insurance-backed guarantees for complete peace of mind."