Basement excavation monitoring
Movement monitoring of neighbouring buildings and retaining structures through basement dig-down, underpinning, raft pour and waterproofing, reported within 24 hours of every visit.
The bulk of our London monitoring
Basement excavations are the most common reason we are appointed in London. We baseline the affected and adjoining structures, monitor through dig-down, underpinning, raft pour and waterproofing, then reduce frequency through the superstructure and fit-out.
Methods
Prism targets on the adjoining buildings are read with 1-second total stations from a stable control network, typically to ±1mm. Where specified we add precise levelling, crack monitoring on neighbouring walls and tilt sensors on retaining structures.
Across London
We cover all 32 boroughs, with most basement work in Westminster, Kensington and Chelsea, Camden, Hammersmith and Fulham, Wandsworth and Richmond. Where a party wall award is in place, see party wall monitoring.
How it works
Specification
Work to the monitoring requirements in the Basement Impact Assessment, party wall award or engineer's specification.
Baseline
Install targets and take two baseline surveys before any works begin.
Through the dig
Weekly readings through excavation and underpinning, reducing through superstructure and fit-out.
Who we work with
Structural engineers
Monitoring specified in a Basement Impact Assessment or temporary works design.
Basement contractors
Clean data to keep works moving and defend against claims.
Party wall surveyors
Reports ready to go straight into the award file.
What clients say
Read our reviews on Google★★★★★
We was looking for a local company to survey our setting out on our new build project and came across THS, We are VERY happy with the service they provided, Tom visited the site and was very helpful and professional. providing a detailed description and was very thorough. we will defiantly be using THS in the near future.
★★★★★
I contacted Tom to carry out a Topographic survey, and cannot recommend them enough. Nothing was to much, and I was kept up to date with everything as it happened! Great company to deal with and reasonably priced.
★★★★★
Superb service, quick turnaround and extremely helpful! I wouldn't hesitate to use THS Concepts again if I need to in the future!
Basement excavation monitoring: common questions
Do London boroughs require basement monitoring?
Many London boroughs require a Basement Impact Assessment, which often specifies movement monitoring of neighbouring buildings. Party wall awards commonly require it too.
How long does basement monitoring run?
Typically 6 to 18 months, from before enabling works until the structure is complete and movement has stabilised.
What triggers are typical?
They are set by the structural engineer. Around 5mm amber and 10mm red for total movement is common on residential basements, with tighter values for sensitive buildings.
Related services
- Setting out
Gridlines, foundations, piles and roads set out on site.
- Measured building surveys
Floor plans, elevations and sections of existing buildings.
Tell us about your site
Send a location, a rough brief and your deadline. We reply with a fixed quote within 24 hours.