The uptake of building information modelling ("BIM") generally, and recognition of its application to sustainability specifically, is gathering pace. NBS recently published in their "10th Annual BIM Report, 2020", the results of their survey of construction professionals, which indicate that 73% of the industry now uses BIM (as compared to 13% back in 2011).
In the fourth piece in our series on sustainable construction, we outline some of the ways in which BIM can be harnessed to achieve greener buildings.
Capitalising on efficiencies
Before the advancement of technology and digitalisation of models, each member of a client's professional team would have to undertake various iterations of their 2D working drawings in response to updates to the project. The cost of developing and reworking design in this traditional manner is expensive, both in terms of the fees payable by a developer client to its professional team for their time and the opportunity cost of not being able to use that time to collaborate and innovate.
The ability to aggregate and store data in one centralised source and then easily tweak factors in the model to determine the impact of a given change, facilitates a quicker, more transparent approach to altering design. The ease by which design can be amended and manipulated offers the potential to foster blue sky thinking, including more sustainable design options, on construction projects.
Logistical opportunities
Developers and their team can also look to use BIM as a planning tool. According to a briefing paper published by the Building Research Establishment ("BRE"), around 10% of UK emissions are associated with the manufacture and transport of construction materials and the construction process.1 If BIM is used to programme when materials will be required on-site, the number of deliveries (and the associated fuel emissions produced by delivery vehicles) can be consolidated and/or reduced.
To counteract overordering construction materials, BIM can be used to quantify the units of each integrant part so that a realistic order can be placed. This would: reduce construction costs as superfluous spare parts would not be ordered; scale down the quantum of natural resources being extracted and used to produce materials that do not end up being used and may end up as landfill; and, shrink the levels of embodied carbon generated to construct a built asset.
Clash detection
A key benefit associated with BIM is that of "clash detection". Once a set of consultants' individual models are federated (i.e. combined), clashes can be identified. The operational cost of remedying clashes at an early design stage of a project is manifestly cheaper than when construction works have already begun.
Of course, clash detection remains important once construction works have started. Consequent delays to the programme will potentially result in additional operational costs and a prolonged period of construction for which there will be an increased toll on the environment. Therefore, BIM remains a vital tool throughout the construction phase.
Can demolishing a building become more circular?
If a model is built to illustrate how a building is constructed, then equally, that model can be used to determine the most sustainable way to demolish that building. The model can log the composition of the building giving the owner greater opportunities to either recycle the component parts as new products or reuse the demolished/waste materials as part of new construction projects.
Analysing the data stored within BIM models to determine how materials can be repurposed or recycled ahead of demolition should lead the industry away from a "purchase-use-dispose" mentality. Viewing the life span of construction materials from a more cyclical perspective is integral to the deceleration of consumption of raw materials and the stockpiling of materials at landfill sites – as we discussed in last week's post.
Management of the built asset
BIM creates a centralised data storage system which permits a facility and/or asset manager to gauge the performance of a building. This, in turn, will allow the management team to take a proactive approach to ensure that the building is operating as efficiently as possible. The BIM process should also invite cross-disciplinary discussions between construction/design teams and the facility/asset management teams. Experience can be shared and design updated through BIM to build an asset that will be more environmentally friendly to operate.
Learning from past data
It would be short-sighted to view the utility of BIM as expiring on the demolition of the building for which the model was originally produced. The BIM model can provide a rich data source following a building's demolition.
The information collated and stored within the model in respect of energy efficiency, materials/products used, etc., can be synthesised and used to inform the planning stage of future developments. Equally, the insights obtained from a sustainability perspective from one construction project are transferable to another.
Adoption of BIM and the integrity of the BIM model
There is an abundance of opportunities and synergies to exploit between BIM and a more sustainable built environment. However, the value derived from BIM is contingent on the quality of the material inputted by the project team.
As more and more clients mandate use of BIM, supply chains will need to build up their BIM competencies in order to tender competitively. The initial financial outlay to acquire BIM infrastructure/software, and likely upskilling required, will only be worthwhile if a proactive and committed approach to integrating BIM on a project is taken from the outset.
For construction lawyers this means scrutinising the contractual mechanisms by which BIM is integrated into construction contracts to ensure they reflect both what the client wants to achieve and how BIM-related responsibilities are delineated between the parties.
As more stakeholders prioritise sustainability as a key objective and start to use BIM to help achieve net zero, the need for nuanced and technical drafting is set to increase. The current move from a national standard towards the new international BIM standard (ISO 19650 series), presents fresh opportunities, especially for developer clients and their project team, to really engage with BIM and harness what it has to offer to help achieve ambitious sustainability targets.
Author: Lauren Hutchison
- https://www.bre.co.uk/filelibrary/Briefing%20papers/98660-Sustainable-Refurb-Briefing-Paper.pdf
