THINK PIECE
BIM and improved carbon performance Does it happen?
Energy Mix
Capital Carbon
Operational Carbon (carbon when infrastructure /facility/product in use)
Whole Life Cost
Life Cycle Analysis
Quality
Longevity and Durability
Trade-offs
Scenarios
Optioneering
CEEQUAL
Building Information Modelling
Collaboration
Coordination
One Change
Risk Awareness
Risk Avoidance
Risk Mitigation
(embodied in a product /embedded during construction)
Energy mix
Conflict Resolution
Stakeholder Engagement
Introduction URS’ major infrastructure clients are looking to embed Building Information Modelling (or BIM) as a tool to assist in the feasibility, design, construction and maintenance of their assets. Improvements in carbon performance are reputed and expected to be a key outcome from deploying BIM, but is that the case? URS has prepared this short think piece to discuss the links between BIM and carbon performance and set out ways in which this relationship can be manifest through our experience and results working on buildings and major infrastructure projects to date.
Policy, regulatory and procedural drivers The following is taken from the UK Government’s BIM Task Group website: The Government Construction Strategy was published by the Cabinet Office on 31 May 2011. The report announced the Government’s intention to require: collaborative 3D BIM (with all project and asset information, documentation and data being electronic) on its projects by 2016. Essentially the UK Government has embarked with industry on a four year programme for sector modernisation with the key objective of: reducing capital cost and the carbon burden from the construction and operation of the built environment by 20%. Central to these ambitions is the adoption of information rich Building Information Modelling (BIM) technologies, process and collaborative behaviours that will unlock new more efficient ways of working at all stages of the project life-cycle. [Accessed 20.09.2013: http://www.bimtaskgroup.org/] Working closely with various Government and Industry groups, URS are at the forefront of BIM development and delivery within the UK. URS were active in the development of the 2011 UK Government BIM Strategy, and we were credited for our contribution to this publication. This document was the first Government document to highlight the need for BIM following the publication of the Government Construction Strategy. All major infrastructure providers in the UK are preparing to comply with this requirement and establish or further embed BIM as a collaborative tool across the life cycle of assets.
A report for the Government Construction Client Group Building Information Modelling (BIM) Working Party Strategy Paper
March 2011
Building Information Modelling (BIM) Working Party Strategy
What’s out there?
Carbon as a BIM attribute
Is BIM and carbon performance central to the main civil engineering sustainable assessment process, CEEQUAL? While CEEQUAL sees carbon as a key performance indicator, the link with BIM and carbon performance is not yet explicit – this is expected to change at future CEEQUAL revisions. With carbon foot-printing and performance being a subset of life cycle analysis, our discussion covers the following issues, which include quality, big data, whole life costs and materials and operational considerations. The final quarter of 2014 shows that there is a raft of online literature with plenty of generic assumptions that BIM helps to improve carbon performance. Within the Construction Industry, built environment experience is more established and has seen tangible benefits from BIM processes for longer than that of infrastructure. With the examples that are available for buildings and energy related modelling that can be learnt from; few details and data from specific projects appear to have been chronicled, so opportunities can be realised about where carbon performance is likely to be improved through deploying BIM.
ICE thought leadership
Green economy
The Institute of Civil Engineers (ICE) has identified a place for considering carbon emissions from the construction and operation of infrastructure in the same way as CapEx and OpEx has always been incorporated (see the ICE report: Building a Sustainable Future ICE low carbon infrastructure trajectory – 2050). In this sense, Operational Carbon is that set of carbon emissions associated with the particular set of infrastructure / facility / product when in use, while Capital Carbon is those emissions embodied in a construction product or embedded during the construction process.
Thinking in those terms, carbon in relation to BIM is most readily useful where the attributes of materials and components in a design (be it Building or Infrastructure) each have an industry accepted carbon emission factor or metric associated with them. Therefore, any adjustment in material requirements and component specifications has both a financial cost and carbon cost indication. When aggregated using a BIM process, assuming that the brief and model environment have been set up correctly from the outset; any shift in the overall design model will automatically indicate the costs or savings in carbon associated with the change, empowering stakeholders with the decision-making process where carbon emissions are concerned. BIM is not about directly reducing carbon, rather it is revealing how changes to the design may reduce carbon – a process delivered with revelatory tools. URS has understood this intrinsic link between carbon and cost and deployed that learning through an innovative tool for understanding the whole life cost of alternative road refurbishment programmes: WLCO2T. WLCO2T Case Study: Use of Full Carriageway Closures for Road Pavement Maintenance – Transport Scotland, UK URS was commissioned to develop a whole life cost model and also study the safety and construction quality issues of implementing 24hour carriageway closures for road pavement maintenance. This was instead of the more traditional approaches to traffic management such as over-night closures or contraflow. URS made use of published material from previous research to develop the whole life cost model and analysed a range of maintenance schemes with different carriageway types, in different locations around Scotland. A Road User Perception Survey was carried out to understand the views of the travelling public. URS used WLCO2T to study the carbon footprint of alternative maintenance strategies, and showed that the proposed 24-hour closures mitigated the impact of works on the environment, through reduced quantities of construction material and fewer construction traffic journeys thereby generating a smaller carbon footprint. WLCO2T is readily adapted to other kinds of infrastructure and so interfacing WLCO2T with an overall BIM for a particular project would reveal where carbon and cost savings can be jointly achieved. The important point is that BIM itself does not directly reveal carbon savings, it is only where carbon is attributed to the costed elements of the BIM model, for example through WLCO2T, that the gains or savings in CapCarb and OpCarb are identified.
B uilding a
S ustainable Future ICE low carbon infrastructure trajectory - 2050
Building a Sustainable Future
Whole life costs are directly linked to product life cycles, so where a BIM process is utilised which includes the carbon attributes of its component parts, this helps in decision-making with respect to quality. There are many applications of this thinking, for example once embodied carbon is established there is a cost and quality debate
BIM for optioneering over longevity, durability and embodied energy of the component parts of any structure – this affects decisions over maintenance and refurbishment cycles / and operational benefit versus material footprint. For example, working on energy models for office buildings, brise soleil solar shading devices are often favoured as an energy conservation measure – reducing the thermal gain of the building and thereby reducing the energy spent on cooling. However, when the full life cycle of the brise soleil is considered next to the carbon emissions of ventilation and air conditioning, the picture is not always so clear cut. Careful consideration needs to be given to the material used to manufacture the proposed brise soleil. Energy is saved by avoided cooling; however the brise soleil components may be made of materials high in embodied carbon, so their carbon intensity might outweigh the benefits of reduced emissions from less cooling. While such lifecycle calculations cannot be achieved simply by switching to a BIM process, the use of BIM allows these issues to be readily revealed and addressed at the design stage. Likewise with quality, where cheaper material specifications which may have a lower embodied carbon footprint, but don’t last as long (and have to be replaced more frequently) they typically add up to a more carbon intensive (and perhaps costly) overlay solution than an option that is more durable, lasts longer and has to be maintained or refurbished less frequently – BIM shines a bright light on this old argument of quality and capital cost over operational cost. In this sense, BIM can improve carbon performance, simply by effectively making more information available for decision-making: part of the contributing factor to an improvement in performance is the ability to design with full information available as you go. In a BIM authoring tool like Autodesk Revit, the ability to get an updated report on the annual carbon footprint for the current design can be obtained on the basis that the correct object and asset information, mechanical system types and building location is provided. As a facility design is refined, the author can know the positive or negative performance impact of each decision. The power of just knowing this information is a significant factor in how BIM can improve building performance, or design performance in general.
A BIM process provides a lens for reviewing design scenarios quickly before construction begins; this can be further leveraged for a carbon impact provided there is strong interface between material / object durability, longevity and carbon attributes versus cost. With the necessary background data using processes, BIM can reveal how small adjustments impact overall scenarios, so making optioneering that much easier. Many are now familiar with the adage that with BIM you build a structure or facility twice: once virtually and once for real. One of the most important value propositions for BIM is comparing and reducing the overall carbon impacts and associated costs of numerous, and diverse design options and scenarios (i.e. total layout and footprint of infrastructure over a landscape). Design Clash resolution is a key area of savings in resources, planning, statutory permissions, and materials waste. Looking ahead to construction; when linked to GIS, BIM can optimise logistics and delivery pathways for on-site construction and materials delivery linked with handling nodes, building on time and motion impacts to minimise construction downtime and enhance safety. These operational savings are harder to link directly with carbon performance, but there is no doubt that savings in time and materials deliver enhanced carbon performance. BIM implementation is only as successful as the process in which the data is generated. Teams need workflow instructions, training, and support to ensure successful BIM execution. Generating documents such as BIM Execution Plans (BEP), Process “Quick Guides”, and data management policy helps define roadmaps for project teams and clients to follow for productivity and collaboration on large, multi-discipline projects. BIM is not a single technology or solution and as project deliverables evolve from graphical 2D drawings to rich 3D data environments this is a process potentially under pinned by a variety of technologies. The BIM community understands the importance of remaining diverse and flexible with technology, such as Autodesk and Bentley.
There are many benefits that can be realised from a BIM approach, and they do not just impact one project stakeholder: Clients, Consultants, Constructors & Sub-Contractors can all benefit from the process of a BIM enabled project and Common Data Environment (CDE).
BIM as living blueprint / live archive for learning The benefits realised by BIM related to carbon performance are a function of its value as a digital process and design archive with associated material, component and, where designed, carbon attributes. Taking a modular approach to major construction and infrastructure is more efficient with BIM and makes referencing for future projects more straightforward: the performance of objects with carbon attributes can be monitored over time while links to durability, longevity and quality issues allow performance in use to be catalogued providing much easier future access than a paper archive. The URS BIM Playbook provides the project stakeholders with an understanding of what to expect during the delivery of a project. It is for all of the project team, whether they are at the strategic and managerial or technical delivery level of a project. Collectively, all have an important part to play in delivering BIM successfully. The BIM Playbook stages are based upon the industry recognised project stages as defined within PAS11922: 2013 Specification for information management for the capital/delivery phase of construction projects using building information modelling.
Summary In summary requirements for achieving improved carbon performance with BIM includes: • Good CapCarb and OpCarb index of emissions linked to BIM attributes • Latest software from Autodesk or alternative • Advanced Modelling through industry standards, or client defined bespoke requirements together with lots of processing power and intelligent analytics to reap the rewards from this – URS advanced modelling techniques can help.
06 07 05 04 02 03 01 00
BIM Playbook
PRE-BRIEF
BRIEF
CONCEPT
DESIGN
DEFINITION
URS would expect its design teams to have a basic understanding of what BIM means…
The performance benchmarks are set by the client and any site constraints are known. The project information set can…
The anticipated project information shall communicate the initial response to the brief, aesthetic intent and…
Project Information would be coordinated to communicate the response to the brief…
Project Information shall be dimensionally correct and coordinated and can be used to verify compliance…
BUILD & COMMISSION
HANDOVER & CLOSE OUT
Information is an accurate representation of the asset before and during construction…
Information would present an accurate record of the ‘as constructed’ asset at handover…
T&DS
OPERATION An updated record of the asset at a fixed point in time incorporating any major changes made since handover…
Carbon performance benefits of using BIM on major infrastructure projects.
Use of BIM allows modelling of an investigation of different construction materials, to determine which is most effective to reduce in-use energy consumption, or embodied carbon, or waste production. Reduction of resource use results in lower carbon emissions, energy and water use and cost. BIM can be used in infrastructure projects to consider the impact of site conditions, health & safety and route planning at the design stage.
Creating the Best Digital Engineers in the World
Business as Usual
29 October 2014, Lancaster London Hotel
Topics include: An overview from Sellafield on the BIM nuclear strategy The trials and development of a Highways Agency BIM early adopter BIM for contractors BIM requirements for clients panel session BIM for asset information management
SILVER
ICE BIM 2014 GOLD
BIM is used from concept design through to post occupancy assessment. The authoring and modelling tools can be used to check the design at outline or detail stage against environmental requirements, as well as cost. BIM can help identify priorities for carbon reduction through modelling alternative options at an earlier stage of a project.
The 2014 ICE BIM Conference will see URS give a presentation on ‘The Benefits of BIM beyond 3D Collaboration and Enhanced Team Communication’. The focus will be on mixed data types and data interoperability utilising a mix of 2D and 3D data from multiple authoring applications in a single project environment across single and combined vertical and linear projects.
PLATINUM
UK Government policy requires the use of BIM across all public sector building and infrastructure projects by 2016. The use of BIM is increasing across the construction industry and is seen as a useful tool not just for building projects.
Once the infrastructure project is complete, BIM can be used to provide handover data including actual cost, actual programme and actual carbon performance. To obtain the full benefits of what BIM has to offer, the process must be used with appropriate embodied carbon data included in the material and process specification.
SPONSORS BRONZE
Benefits of using BIM include improving performance in terms of its cost, value and carbon performance. Use of BIM can allow organisations to manage their use of resources, to demonstrate value for money by reducing costs and meeting environmental objectives such as carbon performance.
Featuring expert speakers from:
HM Government BIM Working Group Sellafield Ltd Manchester City Council Network Rail URS Transport for London Cavendish Nuclear Cabinet Office Laing O’Rourke Crossrail Costain BAM Nuttall Limited Capita CH2M Hill @ICE_BIM
Registered charity number 210252. Charity registered in Scotland number SC038629.
ICE engineers
ice-bim.com
ICE BIM 2014 Business as Usual
CONTACT Robert Spencer Director – Sustainability Business Line Mobile: +44 (0)7765 242 482 robert.spencer@urs.com James Daniel Technical Director Mobile: +44 (0)7825 246 037 james.daniel@urs.com
References http://www.bimtaskgroup.org http://www.wrap.org.uk/sites/files/wrap/Resource%20efficiency%20through%20BIM%20-%20a%20Guide%20for%20BIM%20Users.pdf http://www.rics.org/uk/knowledge/bcis/about-bcis/bcis-on-bim http://www.bimtaskgroup.org/wp-content/uploads/2012/03/BIS-BIM-strategy-Report.pdf?bcsi_scan_E956BCBE8ADBC89F=0&bcsi_ scan_filename=BIS-BIM-strategy-Report.pdf http://www.openbim.org/case-studies/interoperable-carbon-information-modelling
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