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EVORA EDGE: IMPACT Case Studies

By Karen Duffin on Wednesday 20 December 2017

EVORA EDGE are using IES IMPACT tools to deliver material selection and cost analysis to their clients as part of an integrated BIM process. The following projects are just two examples of how they have been using the tools to date.

Guildford Borough Council

In 2011, Guildford Borough Council (GBC) introduced a mandate to reduce carbon dioxide emissions by 10% through the implementation of Low and Zero Carbon technologies.

To encourage sustainable growth, GBC appointed EVORA EDGE to perform a capital cost assessment to determine the additional cost to developers should this target be increased to 15% or 20%, against a 10% baseline cost.

As part of their innovative BIM:SAM (Building Information Modelling for Strategic Asset Management) approach, EVORA EDGE employed IES Virtual Environment (IESVE) software for the creation of a detailed BIM model and impact assessment.

To determine the possible built emissions rate from each asset type, the project team undertook SAP modelling for domestic properties and SBEM/DSM modelling for non-domestic properties. This provided a baseline against which CO2 reductions could be measured for any given technology.

Using the import functions within IESVE, EVORA EDGE were able to bring converted DXF drawings and existing models into the software to create a virtual mixed-use scheme. The two principal modellers involved in the project, dealing in SAP and SBEM/DSM respectively, modelled various buildings and shared their data using a federated (level 2) BIM process. The team also performed calculations in IESVE to determine carbon emissions, using the same models throughout the entire process to maintain consistency and auditability in their approach.

The IMPACT CostPlan tool within IESVE was used to calculate construction costs within the BIM model and determine whether the proposed increase in CO2 emission reductions would be cost prohibitive. This approach demonstrates 5D BIM, where cost information is intelligently linked to the 3D BIM model and project scheduling data. The BIM model and outputs remain available for future use and, by adhering to the RICS New Rules of Measurement (NRM) Order of cost estimating and cost planning for capital building works, EVORA EDGE have ensured that these outputs can be easily understood and integrated into capital cost planning and asset management even by non-engineering professionals.

Based on the final report and recommendations provided by EVORA EDGE, GBC have since proposed a 20% reduction in CO2 emissions to most new developments in its consultation documents.

“For me, one of the most exciting uses of IMPACT is being able to identify project costs through the model itself. We now have the capability, through BIM, to take an EPC or Part L model and use it for lifecycle and cost analysis, and can integrate and communicate with asset managers through these same models.”Andrew Cooper, EDGE Director/Consultant Engineer, EVORA EDGE

 

Orchard Centre - Retail Extension

EVORA EDGE provided IMPACT modelling using IESVE for this retail development in Didcot, Oxfordshire. The developer, Hammerson, commissioned the IMPACT assessment in order to achieve credits under MAT01 and increase the chance of the project attaining a ‘Very Good’ BREEAM rating.This objective is in line with Hammerson’s overarching desire to make significant reductions across all areas of its carbon footprint and better understand the embodied carbon impact of its development activities.

EVORA EDGE were appointed to undertake the IMPACT assessment while another party – Envision – undertook the BREEAM Assessment.

The first challenge for EVORA EDGE was to assess the suitability of the existing model for an IMPACT assessment. This had already been developed in IESVE for the energy strategy, to demonstrate Part L compliance and to calculate BREEAM energy credits. The building had to be modelled to a high degree of accuracy using the Dynamic Simulation Method (DSM) in ApacheSim. It was imperative to ensure that the model’s geometry was extremely accurate as discrepancies that may only have a minimal impact on the Built Emissions Rate (BER) have the potential to impact significantly on the life cycle assessment by affecting material quantities.

Using the IMPACT tool, material data was imported from the BRE library and assigned to the model, either through the model’s geometry or through a non-thermal constructions option based on quantities provided by the schemes QS and/or project managers.

The scope of the study covered the mandatory building elements detailed in BREEAM Assessor Guidance Note GN08.

The key metric for Hammerson in this study was the embodied CO2. As monitoring of embodied carbon emissions of different types of buildings is a relatively new field of research, the model was benchmarked against standards outlined in RICS’ Methodology to calculate embodied carbon of materials, 1st edition for cradle-to-gate embodied carbon emissions, to establish whether the proposed scheme had a high or low impact.

The study concluded that the environmental impact of The Orchard Centre is within an expected range, based on the nearest matching RICS benchmarks of between 750 and 935 kg CO2eq per m² for comparable buildings.

EVORA EDGE presented a number of recommendations to Hammerson, comprising both minor and major interventions. If implemented, it is estimated that these could lead to a reduction in environmental impact of between 6% and 7% - the equivalent of over 1000 tonnes of embodied CO2.

“My hope is to see greater adoption of IMPACT across the industry as part of the current BIM agenda. If you believe in BIM, naturally you want to be able to exchange models and data, so to be able to expand usability of the models to IMPACT as part of a more streamlined process is of huge benefit to our projects.”Andrew Cooper, EDGE Director/Consultant Engineer, EVORA EDGE