Survey to BIM of the Old War Office, 57 Whitehall

Survey to BIM of the Old War Office, 57 Whitehall

About This Project

Murphy Surveys were engaged by Westminster Development Services Ltd (WDSL) to undertake a comprehensive survey of the Old War Office, 57 Whitehall, London. At over 50,000 square metres, and formerly a working office for the Ministry of Defence, the building is now vacant and will undergo a major redevelopment over the coming months and years.
 
The building was built at the start of the 20th Century and was once the office of Sir Winston Churchill, thus bearing witness to events of the utmost importance during both World Wars. The building is of particular heritage and cultural significance and this must be retained during its renovation. As a result, the survey was undertaken for the purposes of heritage preservation, as well as for design, redevelopment and engineering needs.
 
In order to capture as comprehensive a record of the site as possible, Terrestrial Laser Scanning was utilised as a means of data capture, along with High Dynamic Range imagery of the site. This allowed for an array of deliverables to be produced, which will be used by various stakeholders and contractors throughout the duration of the redevelopment. Currently the information provided is serving the basis for the design team and lead architect, as well as assisting Historic England, structural engineers, MEP consultants, and heritage advisors.
 

Laser Scanning

‘Coloured’ pointcloud data incl. imagery overlay

‘Coloured’ pointcloud data incl. imagery overlay

  • A 3D point cloud dataset was acquired using terrestrial laser scanners in all accessible areas of the site. All scan setups were connected/linked in 3D space to within a tolerance of ±10mm using a comprehensive control network; traversed using high-order Leica Total Stations and aligned to an Ordnance Survey Grid Datum.
  • Scans were performed at high-resolutions in order to capture a suitably high level of detail on ornate period structures as a means of heritage recording. The captured level of detail means that, if necessary, an accurate reproduction of any period feature could be produced.
  • In total, over 3800 scans were performed internally and externally, including HDR Panoramic Imagery taken at each scan location. The latest generation Leica P30/40 series laser scanners were used which has acquired a very ‘clean’ point cloud dataset for use in 3D modelling and 2D CAD plan production.

 

Photographic Record

Screenshots from 360° panoramic image

Screenshots from 360° panoramic image

  • The latest NCTech iStar camera system was utilised to capture High Dynamic Range panoramic imagery at each scan location. Images were subsequently processed into 50MP panoramas, openable using flash player in any standard web browser.
  • A sitemap for each floor/area of the site was created allowing the user to navigate between images. Much in the same way as Google Streetview this provides the user with a form of a virtual tour of the site, as well as a heritage record.
  • The imagery dataset has also been ‘hosted’ online by Murphy Surveys to allow for contractors, Historic England, heritage advisors and other stakeholders to view the imagery over the internet without the need to transfer the large file datasets, in this case over 35GB of images.
  • This form of virtual 360° imagery allows for contractors to remotely inspect the site and visualise its contents, features and conditions
    without physically having to attend the site.
  • The photographic record also provides a timestamped record of all site conditions and contents at the time of handover from the MoD to the new building owners.

 

Two-Dimensional CAD Drawings

External Old War Office Elevation Plan

External Old War Office Elevation Plan

  • A variety of CAD plans were required in order to cover all elements of the redevelopment. These included standard topographical and utility survey plans, as well as Streetscene elevations of all surrounding building elevations drafted to give the building context in its environment and to allow for accurate analysis by right-of-light consultants.
  • Old War Office elevations, floor plans, sectional elevations and roof plan were required to provide accurate measurement information for the redesign and subsequent engineering works.
  • High-detailed CAD drawings (1:10 scale) of significant internal elevations and ornate reflected ceiling plans were required to provide an accurately measured record of features in the high-importance rooms of the building.
  • Plans were drawn to a very high-level of detail in order to accurately represent ornate mouldings, panelling, architraves, fireplaces and other period features.

 

Autodesk Revit BIM Model

  • A Parametric Model was produced to include the architectural and key structural elements of all 1100 rooms within the building.
  • The model consists of searchable database information and contains intelligent parameter based objects.
  • The project scope identified the intent of the information desired and as a result a variety of approaches were needed to ensure these were met.

 

Level of Detail

Due to the nature of the building and its previous usage, different LOD’s were prescribed throughout. The exterior façades maintained a high level, as did those of cultural or historical interest.
 

3D Meshing of Heritage Features

One of the key inclusions was meeting the need for English Heritage. High detailed inclusions of plasterwork were scanned and then processed to produce native Revit families throughout the model.

Client

Westminster Development Services Ltd (WDSL)

Survey Type

Laser Scanning; Photographic Record; Two-dimensional CAD Drawings; Autodesk Revit BIM Model

Area

50,000 sq mtrs +

Category

Case Studies, Laser Scanning & BIM, Survey & Engineering