Projects

BIM smooths the way for City of London refurb

12 November 2018 | By Stephen Cousins

  • Client: Skanska
  • Lead Contractor: Skanska UK, Lead designer: John Robertson Architects
  • BIM Tools: ArchiCAD, Revit, Solibri, Navisworks

A design team, led by John Robertson Architects, has been appointed to redevelop an existing office building in the City of London, to provide 40,000 sq ft of offices over eight levels and 3,000 sq ft of retail use at ground level.

The team proposed to retain and extend the existing structural frame and upgrade internal and external fabric and services to meet standards set out in the British Council for Offices’ (BCO) Guide to Specification 2014, BREEAM Excellent and WELL building standards.

Ambitions for BIM were set out in the developer’s BIM Execution Plan and agreed at contract stage with the consultants, which were tasked with creating 3D BIM models in ArchiCAD and Revit from 2D record drawings and 3D point cloud survey data provided by the client. 

“BIM doesn’t lend itself naturally to refurbishment projects as the structural frame is often inaccessible at the early stages of the project, or printed record information is often inaccurate,” says Agnieszka Szedzianis, BIM coordinator at JRA. “We have learned as a practice that early exposure of the structural frame is important when working with existing buildings, to reduce coordination risks down the line.”

JRA took initial responsibility for creating the federated BIM model and used Solibri Model Viewer to detect clashes between “idealised” structure and “surveyed” fabric, highlighting where further survey information was required.

“Having access to highly detailed point-cloud survey information allowed us to identify differences between our ‘idealised’ model and the surveyed building fabric,” says Imogen Chapman, project architect. “We were subsequently able to highlight issues and address them at the design stage before they became a problem to overcome on site, which could lead to delays.”

Early instruction of the soft-strip demolition works enabled the structural frame to be exposed and the “idealised” BIM model to be verified. Once this exercise was complete, a specialist MEP team was appointed to complete detailed services design within the verified 3D BIM environment. 

Once on board, the client’s facilities management team were able to confirm the level of information they wanted embedded in the BIM model, including specification codes, structural properties, fire ratings and a unique component ID.

“Private clients often have their own standards for BIM, which can make it difficult for us to adopt a single approach or standard within the practice,” explains Agnieszka. “However, as this was approximate to BIM Level 2 we used it as an opportunity to trial the government’s Publicly Available Standards and then simply removed unwanted data from the final BIM model.”

BIM software was also used to generate 3D visualisations and AVR simulations of the building for prospective tenants. To find out more about the building visit www.51moorgate.com