Sensitive site requiring both digital and traditional survey techniques
Given the sensitive nature of the site, CADS took a variety of approaches in order to accurately measure and record the required survey information. Externally and internally in a number of vacant buildings, 3D laser scanners were used to measure and photograph the buildings/rooms. This approach was unsuitable where buildings were still occupied, so traditional hand measurements were used to avoid potential disruption to patients and staff.
The survey took a total of two weeks on-site, with up to five surveyors on-site at any one time.
Approximately 600 scans were taken in total once a control network was established on-site, which involved taking the coordinates of the natural and artificial targets and linking these with the targets within the scans.
LOD3 model of historic building facade
Once back in the office, the scans were registered to produce a point cloud of the site and buildings. Using this point cloud, the LOD3 3D Revit® model was created of the original historic building facades that were being retained. While internally a LOD2 model was adopted as more extensive development was being undertaken.
Approximately 8 weeks were spent modeling the site, often with multiple surveyors working on the model simultaneously. Along with the model, traditional 2D CAD plans were also produced, constructed from both hand measurements taken on-site, and information extracted from the point cloud.
Simon Jones Head of Estates Strategy & Major Capital Dev North East London NHS Foundation Trust
We employed CADS Survey team on this complex and sensitive project because of their technical knowledge and professionalism. The project required the integration of laser captured point cloud data and hand measured data to create the 3D model and CADS delivered this within the agreed timescale and budget.
While we had to allow an additional 30% in the budget for the delivery of the 3D model over the 2D drawings, this has delivered significant value to this project, particularly where we have been able to make fully informed design decisions not only on the location of buildings but also on the impact on the facade and view.
CADS took a very consultative approach to the project, fine tuning the specification for the model to ensure we were able to swiftly integrate it into our design process once it was released and we have been delighted with the result.