How Long Does A Basement Monitoring Survey Take
Basement monitoring surveys run throughout the construction phase — from before works begin until after completion. This guide covers typical timescales for basement monitoring.
Baseline Survey Duration
A baseline condition survey typically takes 1-2 days on site depending on the number of adjacent properties and the complexity of the structures.
Factors Affecting Baseline Duration
Number of adjacent properties — More properties means more survey time.
Property size — Larger properties take longer to survey.
Access restrictions — Limited access extends survey time.
Property condition — Properties with existing cracks or movement need more detailed documentation.
Ongoing Monitoring Duration
Ongoing monitoring runs throughout the construction phase. Typical basement projects in London run for 12-18 months from start of excavation to completion.
Monitoring Frequency
Monitoring frequency depends on the construction phase and planning requirements:
Weekly — During active excavation and structural works.
Fortnightly — During less active construction phases.
Monthly — During fit-out and completion phases.
Reporting Frequency
Weekly reports — During critical construction phases.
Monthly reports — During less active phases.
Alert notifications — As required when trigger levels are approached.
Final Report Duration
The final monitoring report is produced after construction is complete. Typically takes 2-4 weeks after the final monitoring visit.
Planning Application Timelines
Some planning authorities specify minimum monitoring periods:
Westminster — Often requires monitoring throughout construction with monthly reporting.
Kensington and Chelsea — Similar requirements to Westminster.
Other London boroughs — Requirements vary; check with your planning officer.
When to Start Basement Monitoring
Before Works Begin
Baseline survey should be completed before any works begin. This establishes the pre-works condition and provides the reference data for all subsequent monitoring.
After Party Wall Awards
Monitoring typically commences after party wall awards are in place, though baseline surveys can be completed before awards if access is agreed.
Before Excavation
Final monitoring targets should be installed and initial readings taken before excavation commences.
Typical Basement Monitoring Timeline
| Phase | Duration | Monitoring Frequency | |---|---|---| | Pre-works baseline | 1-2 days | One-off survey | | Excavation | 3-6 months | Weekly | | Structural works | 3-6 months | Weekly/fortnightly | | Fit-out | 3-6 months | Monthly | | Post-completion | 1-3 months | Monthly |
London Coverage
icelabz provides basement monitoring surveys across all London boroughs.