FAQs
Construction Monitoring in New York
to Readily Maintain DOB Compliance
Frequently Asked Questions
When is construction monitoring required in NYC?
NYC DOB requires construction monitoring when excavation, demolition, or foundation work occurs near occupied or landmark structures. A licensed PE determines the scope based on proximity and project type.
What standards do you use to measure safe vibration levels?
We apply USBM RI 8507 and OSMRE criteria, limiting particle velocity to 0.25 in/sec at frequencies below 40 Hz and 2.0 in/sec at frequencies between 40 and 100 Hz.
How quickly can Liberty mobilize for a new project?
We prioritize rapid mobilization to meet NYC DOB timelines. Once a monitoring plan is approved, our team can typically deploy equipment and begin monitoring within a few business days.
Who receives the weekly monitoring reports?
Reports are distributed to the general contractor, property owner, and any other parties named in the monitoring plan. DOB submission copies are provided when required by the approved project filing.
What happens when a vibration threshold is exceeded?
All parties receive immediate written notification. Construction activities must stop until our PE reviews the data, identifies the cause, and approves remediation measures before work resumes.
Is a pre-construction survey legally required?
It is required or strongly recommended under NYC Building Code 3309 for work near occupied structures. A certified survey also substantially reduces contractor liability regardless of formal DOB requirements.
