Case study //

3D Digital Twin – Roof Inspection of ‘The Narrow’

Category: Asset Inspection

Client: Thompsons (Sigma Group)

Date: March/April 2021

Summary: Detailed aerial inspection and generation of a Digital Twin 3D model of Gordon Ramsey’s ‘The Narrow’ restaurant, allowing safe remote inspection, focussed access planning and detailed condition reporting.

HexCam was appointed by Thompsons (part of the Sigma Group) to carry out a high resolution aerial survey of Gordon Ramsey’s ‘The Narrow’ restaurant as part of a major refurbishment and relaunch as ‘Bread Street Kitchen & Bar’. The aim of the survey was to provide a detailed 3D model or ‘Digital Twin’ that would allow surveyors to remotely identify areas of concern and to pinpoint where focussed physical access (scaffolding or MEWP) might be needed.

The site is immediately adjacent to the River Thames at the entrance to the Limehouse Basin and in the shadow of neighbouring tall residential apartment buildings (Chinnocks Wharf). To build the 3D model views of the roof areas were needed from all angles meaning that the drone needed to fly extremely close to Chinnocks Wharf. Close coordination with residents and sharp visual observation skills were needed to capture all imagery in a safe manner.

Aerial and ground images were combined with ground laser scan (TLS) data to produce a highly detailed ‘Digital Twin’ 3D model of the building presented to our client using the ‘Twinspect’ inspection platform provided by our carefully selected partners at Twinsity.

The Twinspect platform allows building surveyors to carry out a detailed remote inspection, annotating and reporting directly on the Digital Twin but supported by, and with access at all times, to the original high resolution images.

Example 3D Model ‘Twinspect’ Deliverable

An example of the surveyor’s ‘dashboard’ view is shown above:

This view shows all of the surveyor’s inspection annotations on the left, the annotated 3D model in the centre and the original high resolution imagery on the right. The surveyor can navigate or ‘fly’ around the model in 3D space to carry out a detailed desktop inspection.

Clicking on an annotation in the 3D model view will show the surveyor’s comments and recommendations as well as quickly displaying all of the original high resolution images that include the point of interest.

Because all annotations are linked in 3D space to the fully georeferenced model, there is no risk of a surveyor identifying and reporting the same anomaly twice as can happen when simply reviewing multiple, near identical images presented in folders.

The Digital Twin can be used to accurately measure distances and areas on the building (for example for detailed physical access planning and BoQ take-offs) and, once fully annotated, traditional PDF condition reports can also be generated. The model can be shared with different teams, with different access rights, to communicate results and recommendations and to produce measured building survey drawings.


Image showing zoomed in section of 3d model image.