Basement specialists, not generalists
IG Building is a London construction company that has made below-ground work its specialism — because basements done properly demand a team that does them all year round.
Who we are
IG Building is a trusted London basement contractor. Over the years we have delivered general building, renovation and structural projects across the capital — and found that the work we do best, and enjoy most, happens below ground.
Today we are London basement specialists, focused entirely on basement construction: excavations and dig-outs, sequenced underpinning, reinforced concrete structures, certified waterproofing and full basement conversions. Our project list includes a double-storey basement in Earl's Court, dig-outs in Fulham and Chiswick, and structural and waterproofing works across west, north and central London.
Below-ground work rewards method and punishes shortcuts. That shapes how we run every site: strict sequencing, engineer's inspections at every stage, tidy sites and honest communication with clients and neighbours alike.
Accreditations & assurance
Certified Delta Membranes contractor
Trained and certified to install Delta cavity drain waterproofing systems — with manufacturer-backed guarantees.
Certified Wykamol contractor
Certified installer of Wykamol waterproofing and damp-proofing systems for below-ground structures.
Engineer-led delivery
Every structural scheme is built to a structural engineer's design and inspected stage by stage with building control.
Fully insured
Comprehensive insurance cover for structural below-ground works. Documentation available on request.
How we run a project
One team carries your project from the first site visit to handover. You get a single point of contact, a clear itemised quote, and a build that follows the engineer's drawings — not improvisation. Where a project needs planning consent or a party wall agreement, we work alongside your architect, engineer and surveyor as one delivery team.
Planning a basement project? Let's talk about it.
A free, no-obligation site visit and quote. We'll tell you honestly what's possible under your property — and what it will cost.