What Is a Structural Monitoring Survey?
A structural monitoring survey (building movement monitoring) is a specialised surveying technique that measures movement, deformation, and structural integrity of buildings and infrastructure over time. Reflective targets and prisms are installed on the structure; robotic total stations measure positional changes to ±few mm accuracy.
| Aspect | Details | | --- | --- | | Purpose | Track displacement, strain, vibrations, crack widening, and settlement | | How it works | Targets/prisms installed on structure; robotic total stations measure changes | | Accuracy | ±Few millimetres | | Types | Manual (periodic visits) or Automated (24/7 real-time with alerts) |
When It's Needed
- Adjacent construction: basement excavations, piling, demolition, tunnelling
- Party Wall Act 1996: extensive works affecting adjoining properties (basements, underpinning)
- Visible defects: widening cracks, leaning walls, uneven floors suggesting subsidence
- Planning conditions: Westminster, Camden, Kensington & Chelsea often require monitoring for basement impact assessments
- Critical infrastructure: bridges, historic buildings, high-rises, rail-adjacent works
- Underpinning and basement works: pre- and post-works monitoring of adjacent structures
Deliverables
- Detailed report with CAD drawings, heatmaps, graphs, and photographs
- Spreadsheet data showing movement values (positive/negative displacement)
- Baseline readings plus ongoing comparison data showing trends over time
- Real-time alerts via SMS/email if tolerance thresholds are breached (automated systems)
- Methodology statement and equipment calibration records
Costs in London (2025)
| Service | Price (ex VAT) | | --- | --- | | Initial installation inspection | £75 per visit | | Standard monitoring visit and report | £295–£450 per visit | | Precision monitoring (mini prism, 0.01" instrument) | £630+ per visit | | Automated 24/7 monitoring | Bespoke quote (site-dependent) |
Total project cost depends on frequency (weekly/monthly), duration, and number of targets.
London Coverage
We provide structural monitoring surveys throughout all of London — North, South, East, West London and the M25 area — plus the South East (Surrey, Sussex, Kent, Essex, Hertfordshire).
Turnaround Time
| Phase | Timeline | | --- | --- | | Mobilisation | Fast — often within days | | Initial report | 1–3 working days after first visit | | Ongoing reports | After each monitoring visit (same day or next day) | | Real-time systems | Instant alerts when movement detected |
Frequently Asked Questions
Q: What is the difference between manual and automated monitoring?
Manual monitoring involves periodic surveyor visits at agreed intervals (weekly, monthly). Automated monitoring uses permanent sensors with 24/7 real-time data and instant alerts when thresholds are breached. Automated is more expensive but provides continuous protection.
Q: When do I need structural monitoring?
You typically need monitoring when planning conditions require it (especially basement works in Westminster, Camden, Kensington & Chelsea), when Party Wall awards specify monitoring, or when visible defects suggest subsidence or structural movement.
Q: How long does monitoring typically continue?
Monitoring typically runs for the duration of the adjacent works plus a post-works period. Basement projects often require 6–12 months of monitoring. Confirm the programme with your structural engineer.
Q: What accuracy can I expect?
Modern robotic total stations achieve ±1–2mm accuracy for target-based monitoring. Precision monitoring with mini prisms can achieve ±0.01" (sub-millimetre) accuracy.