The Old War Office, UK

The multiple projects at the site over a six-year period formed a number of challenges:

• The initial laser-scan survey was undertaken whilst the property was still partially occupied by the Ministry of Defence (MoD). Numerous measures were implemented for security purposes such as full escorts whilst on site and image editing for the redaction of sensitive information.
• The initial BIM / Revit model was produced to a basic specification for initial structural design only. Additional details, such as the heritage artefacts, were progressively added to the model over several iterations which causes many technical challenges within Revit software.
• Due to the size of the site and complexity of the models, the singular model file became too heavy to be used as an effective design tool. Efforts were made to split the model into various files and work sets to ensure the usability of the model deliverables.
• During demolition works, to ensure changes on site were reflected in the Revit model, Murphy Geospatial maintained a permanent presence on site to provide the client with near ‘live’ updates to the model and ad-hoc geospatial information to suit the asset owners requirements.
• A dilapidation imagery survey was required by the main strip-out contractor as evidence of defects prior to their involvement on site. This presented a challenge of ensuring that all features and surfaces were covered by the photography, resolved using a 360 panoramic camera to ensure full coverage and an online interface that all stakeholders could access and use.
• Verification against design of the ‘pavilion’ proved challenging due to the highly irregular shape and form of the pavilion structure (see right-hand image below of the pavilion ceiling). 3D laser scanning was utilised to capture the as-built structure and a 3D analysis undertaken in Navisworks to assess the accuracy of the build compared to the complex 3D shapes within the design model.