News

Digital ‘golden thread’ for high-rise resi to cost £40m-£80m

12 June 2019

The government is estimating that it will cost landlords and the industry between £40m and £80m to comply with providing a “golden thread” of information and key datasets for new and existing buildings of 18m (six storeys) or more.

The government is looking to mandate the use of BIM on high-rise residential projects as part of a raft of tighter measures to improve safety in higher risk residential buildings. BIM would form a  golden thread of information to improve accountability for decision making and provide information that can be passed over to the landlord.

The government estimates that it will cost between £42,000 and £64,000 for residential high-rise projects in design and construction to adopt Level 2 BIM and meet the new legislation.

Even existing buildings – built before the new legislation – will have to comply and draw up digital data using laser scans, which is estimated will cost up to £30,000.

The Ministry of Housing, Communities and Local Government set out its intentions in a consultation released last week on a new regulatory framework to implement the recommendations set out in the Hackitt Review in the wake of the Grenfell fire in June 2017.

It says in the consultation; “We have modelled costs for meeting the golden thread requirements during design and construction that do not already use Building Information Modelling (BIM) Level 2 and a Common Data Environment (CDE). For affected 18 metres and above residential buildings we expect the unit cost of digitalising information to be £42,000-£64,000.”

“Firms that already comply with BIM Level 2 standards and use a CDE will not see additional costs during the new build process to ensure all gateway documents are digital.”

It points out that dutyholders (for buildings constructed before regulations came into force) will have to gather information required by legislation to meet licencing and safety case requirements. This information must be held digitally and can be gathered in two ways depending on the level of documentation available.

It has also costed this process. Based on assumptions that buildings that currently have inaccurate plans will carry out a 2D CAD plan and evaluation drawing, this will cost between £10,000 and £19,000 per building.

For those starting with no digitised information the cost will be double that. The consultation says: “Buildings that lack most or all of their building information will carry out laser scanning and photogrammetry to create a 3D BIM model, costing in total £16,500-£30,000 per building.

“This information would be updated annually at a cost of £400-£600 per annum, to ensure plans are kept up to date.”

Costs for maintaining the golden thread during occupation will also run into thousands.

Under the proposed regulatory regime under consultation building information will have to be kept up to date once the building is completed or full plans have been digitalised.

The consultation says: “We have costed two alternative ways buildings owners could comply with the golden thread requirements. The first is maintaining a CDE via BIM, estimated to cost around £15,800-£16,700 per annum per building. The second option freezes the BIM model in time and stores the building structure in a cloud server. The estimated annual cost of this option is £1,000 for cloud storage and a one-off transfer cost of £3,000 when the construction is finished.”

For major refurbishment works it says that the golden thread requirements for carrying out major refurbishments are not fundamentally different from the requirements for new builds. “BIM Level 2 standards will have to be used, and documents required for gateways two and three will have to be digital to be compatible for golden thread.

“As with new builds, the majority of refurbishment projects are expected to use BIM Level 2 and a CDE already, so they will not see additional costs. However, a small number are not, and these firms will have a total cost of complying for a refurbishment of £17,000-£27,000 per building. The costs differ from new build because refurbishments are shorter projects and therefore have lower license costs and less data entry.”

The costs of creating and maintaining an up-to-date dataset are £550-£1,170. All buildings with a key dataset will be required to keep this up to date as elements of the building change. This will cost £170-£260 per building.

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