Opinion

Why the golden thread is not sewn up in the building safety plans

26 April 2020

‘Referencing BIM Level 1 alongside Common Data Environments and Construction Operations Building Information Exchange (COBie) is a mess.’ Richard Waterhouse, NBS

Richard Waterhouse, chief executive officer of NBS, calls on the Ministry of Housing, Communities & Local Government to raise its digital ambitions in the forthcoming Building Safety Bill.

Early in April, housing secretary Robert Jenrick announced a series of measures comprising what he called “the biggest change in building safety for a generation”.

This is the government’s response to the Building a Safer Future consultation. While it gives some clarity to the future direction of building regulations for housing above 18 metres, confusion over the digital requirements for both existing and new housing stock remain, with no definition of the “golden thread” data requirements. There is also a nasty surprise in the supporting economic assessment and real confusion around the rationale for the use of outdated BIM Level 1 as the basis for information capture.

Let’s be clear – referencing BIM Level 1 alongside Common Data Environments and Construction Operations Building Information Exchange (COBie) is a mess. BIM Level 1 is to be used in the costing estimates for both new projects and existing housing that falls into the scope of the new regulations. 2D CAD is noted as being the expected baseline for information as a cost-effective way of capturing the data from surveys, and there appears to be an assumption that COBie will then magically appear from these plans. Good luck with that!

Obsolete technology

For new buildings, the documents also reference Level 1. It’s worth noting that in our annual BIM surveys, NBS has been tracking the implementation of the government’s target to get the industry using BIM Level 2 over the last 10 years.

The 2019 NBS BIM Report found that 80% of respondents were using BIM with 72% of respondents using BIM on housing, although only 41% or respondents reported delivering outputs to COBie. Clearly, setting the base as BIM Level 1 is simply madness and risks a jump back to the start of the decade.

So what is meant by BIM Level 1? It was very loosely scoped over 10 years ago and since then, almost all of the reference documents have been superseded. BIM Level 1 is out of date and even at the time, was very poorly defined. Basing the new regulatory system on BIM Level 1 is a recipe for chaos and confusion.

Holding position

So why would this reference be used? There are two possible reasons:

The first is that this is a holding position. The documents indicate that the golden thread data requirements will be defined later and should give us the baseline for information requirements on buildings. The logical starting point has to be the international BIM standard BS EN ISO 19650:2. Hopefully they will also clarify the BIM terminology and ensure that the required data can be tested digitally. The second reason may be the volume of work and skills required to survey the existing building stock.

Let’s look at the data:

There are around 11,000 existing buildings that will fall into the scope of the new requirements and these buildings will need to be assessed to gain the Building Registration Certificate. That is 11,000 measured building surveys with data about the types of systems and equipment that needs to be held within the as-yet undefined golden thread.

The costings indicate that around 2,000 buildings a year could be surveyed (using the top end annual cost estimate of £30m and a median estimated cost per building of £15,000).

This estimate seems a low figure for buildings where we need an accurate set of plans, a detailed understanding of the structural and both passive and active fire systems and a full review of the associated risks. Does this include invasive surveys to understand how the building has actually been built?

So has the baseline been set to keep the costs down (a risky view when we are trying to drive up safety) and do we have enough people with the skills to be able to capture the data in a consistent format that can then be tested by a regulator and assessed as safe? Our surveying colleagues could be quite busy in the future!

Potential lost opportunity

The final version of the Building Safety Bill will need to be much clearer over the data requirements for both existing and new buildings. The inclusion of references to BIM Level 1 is a mistake and should not be acceptable to either the industry or to those affected by the Grenfell disaster.

If this really is intended to be the information baseline, then we will all have lost a massive opportunity to lift the construction industry into the digital age and to ensure that residents live in safe housing.