Appendix: Building LCA and BIM Practices in Denmark

Four LCA specialists were interviewed. The first LCA specialist (LCA-specialist-1), is an engineer at the authority and holds an MSc degree in sustainability. The specialist has been actively involved in sustainable roles since 2019. The second LCA specialist (LCA-specialist-2) has an MSc in architectural engineering and specialises in LCA and sustainability at a large engineering company. The third LCA specialist (LCA-specialist-3 holds an MSc in Architectural Engineering and works as an LCA specialist at an architectural company. The fourth LCA specialist (LCA-specialist-4) has a BEng in Architectural Engineering, is employed by an association and has extensive experience working as a sustainability expert in various companies.

As of January 2023, performing an LCA analysis has become a mandatory requirement for obtaining a building permit for most types of buildings in Denmark

BR18 (bygningsreglementet.dk)

. Additionally, a voluntary sustainable class system has been in place since 2021. There are expectations that a proposed plan to progressively reduce the allowable amount of CO2 emissions by 2029 will be implemented. Currently, the requirement entails a 10% reduction, but it is foreseen that by 2029, the requirement will entail a significant 90% reduction (LCA-specialist-1).

This mandatory requirement applies to buildings with an area exceeding 1000 square meters. For buildings with an area less than 1000 square meters, there is a demand for a declaration of compliance. Certain types of buildings, including cottages, retrofitting and transformation projects, as well as unheated buildings and structures in terrain, are exempt from LCA requirements. Infrastructure facilities are not included in the requirements, but administrators of state own roads and railway has started own initiative call InfraLCA

https://via.ritzau.dk/pressemeddelelse/ny-model-bidrager-til-fremtidens-gronne-transportsektor?publisherId=13559844&releaseId=13640511

(LCA-specialist-1).

To secure a building permit, an LCA calculation is not required. The as-built LCA declaration must be submitted as a part of the completion report before the building can be put into use. LCA calculations are in practice conducted at a minimum during the building permitting phase and before the building is occupied. However, in numerous projects, they are continuously updated throughout the design and construction phases (LCA-specialist-2).

In Denmark, it is mandatory to provide BIM (Building Information Modeling) models for state, regional, municipal, and social housing projects to the client. Nevertheless, it is neither mandatory nor feasible to submit BIM models as a prerequisite for obtaining a building permit (BIM-specialist-1).

Building LCA calculations should adhere to the standards set forth in EN 15978:2012

DS/EN 15978:2012 - Webshop Dansk Standard

, and Environmental Product Declarations (EPDs) should align with EN15804 +A1

DS/EN 15804 + A1:2013 - Webshop Dansk Standard

or +A2

DS/EN 15804:2012+A2:2019 - Webshop Dansk Standard

.

LCA calculations are initiated during the design phase, although it's worth noting that certain certifications only necessitate an as-built LCA calculation to ensure the intended environmental goals are met upon completion of the building (LCA-specialist-2).

These LCA calculations are typically carried out by architects, engineering firms, or LCA specialists, and there is a general consensus regarding the responsible party for conducting the calculations (LCA-specialist-2). There can be discussions between architects and engineers regarding whether the responsibility for LCA calculations and any necessary changes should rest with one party or be divided between them (LCA-specialist-3).

The impetus for LCA calculations often comes from government regulations, particularly since they are mandatory for all new buildings. However, it's important to note that LCA calculations were initiated before becoming a prerequisite for building permits, driven either by client demand for LCA calculations or by a desire to achieve certifications such as DGNB, Svanemærke, or similar standards (LCA-specialist-2 and LCA-specialist-3). These certifications often require the inclusion of LCA calculations as part of the documentation.

In 2023, there is a requirement for buildings over 1.000 m2 to achieve a maximum of 12.0 kg CO2 equivalents per square meter per year, with an expected progressive reduction leading up to 2029. In the same year, a voluntary low emission class imposes even stricter limits, allowing only 8.0 kg CO2 equivalents per square meter per year. It is anticipated that by 2029, the requirements will be further tightened to 7.5 kg and 5.0 kg CO2 equivalents per square meter per year for all new buildings and low emissions buildings, respectively. The assessment period for these calculations spans 50 years. For the government's LCA requirements, modules A1, A2, A3, B4, B6, C3, C4, and D are to be included. (LCA-specialist-1).

For assessing building energy consumption during operation, the mandated approach is to utilise the "SBI-anvisning 213

Bygningers energibehov (build.dk)

"/BE18 energy calculation programme

Beregningsprogrammet Be18 (build.dk)

, which is in compliance with the regulations outlined in 2018/844/EU

Energy performance of buildings directive (europa.eu)

(BIM-specialist-3). The concept uses an energy frame that includes delivered energy to the property for heating, ventilation, hot water, cooling, and potential lighting, multiplied by the relevant energy factor for each energy carrier. The factor is 0.85 for district heating, 1.8 for electrical heating, and 1.0 for all other types of heating multiplied with its efficiency.

It is important to note that while Module D should be calculated, its results should not be included in the total when determining compliance with the specified threshold.

Throughout the design phase, generic and product-type-specific Global Warming Potential (GWP) values are employed, as dictated by regulations. These values may differ from the GWP of the actual installed products and materials.

It's worth noting that the Global Warming Potential (GWP) data provided by the authorities includes some numbers from 2018 that have not been updated to reflect the most current values (BIM-specialist-3).

The authorities provide emissions data in BR18's table 7 and EPD. The table containing emissions data is available in CSV or Excel format. The authority does not provide a predefined format for emission data. In most cases, emission data from product-specific EPDs is manually transferred to LCA tools (LCA-specialist-2).

LCAByg

https://www.lcabyg.dk/en/

has been made available to the industry free of charge. It is developed by Aalborg University and supported by public funding, the future of its continuous development is currently uncertain, as questions arise regarding its funding model. LCAbyg is widely adopted in the industry across various disciplines, although several other tools are also in use. Some alternative LCA tools

https://molio.dk/nyheder-og-viden/netvaerk/contech-lab/aktiviteter/research/baeredygtige-byggeprocesser-og-digitale-vaerktojer-1

that can be utilised during both the design and construction phases include Realtime LCA

Real-Time LCA

, DesignLCA

DesignLCA

, and One Click LCA, while Null Carbon

Nullcarbon

on the other hand, is typically employed later in the design process and during the construction phase. LCA estimator

LCA estimator

is primarily intended for use during the early stages of design.

https://molio.dk/media/5fqntzmi/23w35-oversigt-over-digitale-baeredygtighedsvaerktojer-v01.pdf

Three BIM specialists were interviewed. The first BIM specialist (BIM-specialist-1) is a project manager at the authority. The specialist has studied holds an MSc degree in urban design and a BSc in architecture and has previously worked for a landscape architectural company and participated in landscape design competitions. The second BIM specialist (BIM-specialist-2) is a trained construction architect and a BIM specialist at a large engineering company. The third BIM specialist, (DK BIM-specialist-3, 2023), has an architectural education and serves as a middle manager at an architectural company.

Architects often commence their schematic design in Rhino, and in some cases, they use AutoCAD, SketchUp, or FormZ. However, the design is frequently transitioned primarily to Revit, with secondary use of ArchiCAD for design development. Among engineering companies, Revit is commonly the tool of choice, although Tekla may be used by structural engineers in certain cases Lund. For the majority of projects, Revit, ArchiCAD, or Tekla are employed for creating construction documentation from BIM. AutoCAD is still utilised to produce certain 2D drawings (BIM-specialist-2).

Molio which is a non-profit organisation, along with its predecessors, has gained wide acceptance within the sector, enjoying recognition from both public and private organisations. Over the years, Molio, has played a pivotal role in defining CAD/BIM guidelines and has significantly increased its activities in the sustainability realm. A notable proof of this commitment is LCAcollect, a cloud-based collaborative tool designed for gathering input for LCA calculations during the design and construction phases (LCA-specialist-4).

Dikon represents a consortium of major industry players, established with the primary goal of implementing Molio standards. However, Dikon has gone further by delivering specifications and defining various levels of detail within the BIM framework.

On a different front, BIM7AA was created by a group of architectural firms that recognised the need for a more streamlined classification system. They introduced BIMTypeCode, which has become widely adopted across the sector (BIM-specialist-3).

Most BIM models adhere to the guidelines set by Molio, Dikon, and BIM7AA (BIM-specialist-2 and BIM-specialist-3). Some interviewees pointed out that BIM models generated during the design phases could be quite dynamic, making them less suitable for direct use in LCA without thorough quality control (LCA-specialist-2). Design progress often varies across different disciplines, and models may contain elements that do not pertain to the building or multiple alternatives for the same building component.

In general, building parts are modelled according to Dikon's level of detail and delivery specifications. Molio is currently in the process of aligning its guidelines with ISO 19650 standards.

BIM models are created for nearly all buildings during the design phases. These models are typically generated by the various design disciplines involved, although the responsibility for updating models may vary between contractors and designers.

Denmark hosts several classification systems, yet the majority of projects classify their components according to the BIMTypeCode, a system developed by BIM7AA (BIM-specialist-3). Some companies opt for an internal naming convention and endeavour to have their system adopted by other project participants (LCA-specialist-2). However, given that projects typically have distinct organisational structures, reaching a consensus on naming conventions can pose challenges. In some instances, it may be feasible to pinpoint specific materials, such as an exact concrete recipe, but this is the exception rather than the rule (LCA-specialist-3). In most cases, only the quantity and the overall material for each building component or the sum of components are transferred.

The IFC format is commonly employed for transferring BIM models from proprietary BIM tools to Solibri Model Checker, which is utilised for quantity take-offs. On the other hand, some prefer to use plugins that leverage the internal quantity take-off tools within their BIM applications (BIM-specialist-2).

A number of plugins rely on the LCAbyg input format, which, although documented, does not serve as a universal LCA format for quantities. An ongoing GitHub project called LCAx, initiated by Kristian Kongsgaard, aims to develop an independent format for LCA results.

Given the varying methodologies employed by different tools for conducting quantity take-offs, it's important to note that the same BIM model may yield different quantity results depending on the specific tool used (BIM-specialist-3).

According to Danish LCA regulations, certain building components should only be partially included, a task not typically addressed by default quantity take-off applications. Compensating for this requirement can be accomplished through BIM, quantity take-off, and LCA applications. However, it's worth noting that this can be a complex process, as most applications used in Denmark are international and may not inherently support specific Danish national requirements (LCA-specialist-3).