SX Basement Construction London is reviewed for full basement dig-outs and conversions under terraced properties, with reviewers describing the company managing planning applications, party wall agreements, structural calculations and liaison with Thames Water and building control on the client's behalf. Recurring jobs include underpinning carried out in alternate bays, waterproofing and tanking membrane replacement with new sump pumps and drainage runs to fix persistent damp, and lightwells added to bring natural light into the finished space. Reviewers note that digs typically take longer than a quick job but say the team kept them updated and were upfront when timelines slipped, with no unexpected additions to the final bill. Finished basements are described as dry and usable as extra living space. As a groundworks and excavation specialist in London, SX Basement Construction London holds a 5-star average from 37 Google reviews.
Reviews
5.0 / 5 · 37 totalbeen meaning to write this for a few weeks now. SX did our basement dig out and conversion and the whole thing was way less painful than i was expecting. we went in pretty blind, didnt really know what permissions we needed or how any of it worked, and they walked us through it from the start. paperwork, drawings, council stuff, all sorted by them which was the main reason we picked them over two other quotes. the build itself took longer than the original estimate but not by loads, and they were upfront when things slipped which i appreciated more than a fake timeline. site was kept reasonable, no shouting at 7am, no rubbish piling up on the pavement for weeks. finished basement is dry, properly lit, feels like part of the house not a damp box underneath it. price was fair for what it actually involved once you see the scope
had a basement conversion done under our victorian terrace and these lot handled pretty much everything. planning docs, structural calcs, party wall stuff, the actual build. saved me from having to coordinate like five different people which was the main reason i picked them over other quotes i got around London. the dig took a while obviously but they kept me updated on where things were at and never had to chase them down for answers. waterproofing and drainage all sorted, new staircase put in, the space is basically a full extra floor now. ceiling height came out better than i expected tbh, thought it would feel cramped but its not. one thing worth mentioning is they dealt with thames water and building control directly so i didnt have to sit on hold with anyone. price wasnt cheap but basements never are and there were no surprise additions to the bill halfway through. been using the space as a home office since they finished and its comfortable year round
Our terraced property had practically zero storage and no room to extend outward, so going underground was really the only option we had left. The planning side of it was what worried us most because we'd heard horror stories about party wall agreements and structural surveys dragging on for months. SX Basement Construction sorted all of that out and kept things moving at a reasonable pace. They handled the permissions, lined up the structural engineer, and basically managed the paperwork so we didn't have to chase multiple people ourselves. The actual dig and build took a while, which we expected given the depth and the fact that neighbours were close on both sides, but there weren't any major hold-ups. What we ended up with is a full additional floor under the house - dry, bright with the lightwell they suggested, and properly finished. Went from having nowhere to put anything to having more usable space than the ground floor.
Had this ongoing damp issue in the basement for like 2 years maybe longer. Walls were literally crumbling in spots and nothing was fixing it properly. They came in figured it out. It was a waterproofing failure from the original build and redid the tanking system completely! Bone dry now even after all that rain last month which is wild!!! X
I would highly recommend SIX for their basement construction services. They managed the entire project from excavation to the final fit out with great efficiency and professionalism for us.
Our basement construction project went perfectly. The team managed the job professionally and the finish is flawless.
Massive shout out to the team handling our basement excavation London. Fast,safe,and the results are incredible. Basement builder London legends-thank you!