Construction monitoring in New York City
Excavation, demolition and pile work can move or shake the buildings next door. Grant Engineering documents those buildings before work starts and monitors them while it proceeds, so the project team knows right away when a limit is reached.
What we provide
- Monitoring plans that set out what is monitored, where, how often, the limits that apply, and what happens when one is exceeded
- Pre-construction surveys of neighboring buildings, with a photographic record of existing conditions
- Vibration monitoring with automated monitors that send alerts when a limit is exceeded
- Crack monitoring of existing cracks in walls and foundations
- Tilt monitoring of walls and structures
- Optical monitoring of movement and settlement
- Noise monitoring
Who we work for
- Developers and contractors who need monitoring for their own project
- Owners of neighboring buildings who want their own independent readings
- Engineers and other monitoring firms who need plans, installation or reporting support
Common questions
When is monitoring required?
The Building Code requires it for most excavation, underpinning and foundation work next to existing buildings, and for some demolition next to attached buildings. Historic structures get added protection, described below. The approved drawings say what applies to your project. Send them to us and we will tell you what is needed.
What are the limits next to a landmark?
For historic structures, DOB's Technical Policy and Procedure Notice 10/88 applies. It covers designated landmarks, buildings in historic districts and National Register properties that adjoin the site or are within 90 feet of it. It limits peak particle velocity to 0.5 inches per second and movement of the historic building to 1/4 inch, and it calls for telltales across existing cracks and a seismograph at the nearest historic structure.
What are the limits for other buildings?
The engineer who prepares the monitoring plan sets them for the site, usually on the support of excavation drawings or a dedicated monitoring plan.
What happens when a limit is exceeded?
The monitor sends an alert to the project team. If the stop-work limit is reached, the work causing it stops until the engineer has reviewed the readings.
Can you start quickly?
Call us with the address and the drawings that set the monitoring requirements. We will tell you what is needed and when we can install.
Code references
DOB Technical Policy and Procedure Notice 10/88, Procedures for the Avoidance of Damage to Historic Structures Resulting from Adjacent Construction. NYC Building Code Chapter 33, Section 3309, Protection of Adjoining Property. Chapter 18, Soils and Foundations.