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Appendix: Building LCA and BIM Practices in Norway

Building LCA in Norway

Interviewees’ background

Four LCA experts were interviewed. The first expert has 10 years of work experience with environmental management in the construction industry, such as greenhouse gas calculations of buildings and BREEAM. Special expertise in reducing greenhouse gas emissions in ambition projects with objectives within ZEB, BREEAM, and FutureBuilt. The second expert has worked with life cycle assessment (LCA), input-output analysis and material flow analysis focusing on the carbon footprint of building materials, household consumption as well as preparation of environmental product declarations (EPDs). The third expert has also worked with life cycle assessment (LCA), input-output analysis and material flow analysis with focus on carbon footprint of household consumption, municipal service production and environmental impact of buildings and water and wastewater treatment, as well as preparation of environmental product declarations (EPDs). The fourth expert has worked with reuse mapping within the construction industry and has coursework in subjects such as life cycle assessment, sustainable constructions, ecology, and renewable energy.

National building LCA regulation

Building Acts and Regulations in Norway are described in TEK 17: Regulations relating to technical requirements for construction works (Building Technology Regulations) sets in §17-1 Climate gas calculations for materials, requirement that a building LCA for materials shall be included for construction of commercial and apartment buildings (Byggtekninsk forskrift (TEK17) med veiledning, 2017). The TEK 17 guide describes the regulations on technical requirements for buildings, i.e., the minimum characteristics and what buildings must have in order to be legally erected in Norway.
The TEK17 Regulation is intended to ensure that projects are planned, designed and executed on the basis of good visual aesthetics, universal design, and in a manner that ensures that the project complies with the technical standards for safety, the environment health and energy. The requirements for climate gas calculations for materials were introduced on 1 July 2022, and one year transition period was given. This means the requirements are mandatory from 1 July 2023. These requirements apply to materials in the building. The requirement is valid for new construction and major remodelling of buildings. A major remodelling is not precisely defined in the regulations, but it entails changes or repairs that are so extensive that the entire building essentially appears to have been renewed. 
In the TEK17 Regulation chapter 17, there are requirements to what building parts that must be included in the building LCA and which parts of the life cycle are minimum required. The building LCA must at least include seven building parts according to Norwegian Standard NS 3451:2022 Bygningsdelstabell (table of building elements):
  • 215 Pile foundation
  • 216 Direct foundation
  • 22 Structural frames
  • 23 Outer walls
  • 24 Interior walls
  • 25 Floors/slabs
  • 26 Outer roofs
Other building elements, like outdoor areas and technical systems, are not included. The included life-cycle modules (according to standard EN15978) are as follows: A1-A3, A4, A5 (only waste from construction site), B2 and B4.
The requirements for building LCA were introduced 1 July 2022, and one year transition period was given after which building LCA of materials has become mandatory. The requirement is valid for new construction and “major remodelling” of buildings. A major remodelling is not precisely defined in the regulations, but it entails changes or repairs that are so extensive that the entire building essentially appears to have been renewed. The building LCA must be based on NS 3720:2018 standard (Standard Norge, 2018). According to the technical regulations (TEK) calculations shall be done for new apartment buildings and commercial buildings.

New apartment buildings

Apartment buildings are all housing buildings that are not “småhus” (small house in Norwegian). “Småhus” are defined in the guidance document for TEK17 §1-3 as single-family homes, semi-detached homes (up to four units), townhouses, and terrace homes up to three floors. This is coherent with the definition of apartment buildings in NS3457-3:2013 (Standard Norge, 2013). Low-rise block in with two floors and more than four housing units are defined as apartment buildings and not as “småhus”. This is for instance semi-detached houses with 6 and 8 units. The requirement for carbon footprint calculations is also valid for vacation homes that are not “småhus”.

New commercial buildings

TEK17 does not specify what is meant by commercial buildings. In this context commercial buildings are all building types which are not defined as housing. According to NS 3457-3:2013 (Standard Norge, 2013) this means the following buildings:
    • 2 Production and storage buildings
    • 3 Office and business buildings
    • 4 Transport and telecommunication buildings
    • 5 Accommodation, dining and service buildings
    • 6 Educations, sport and culture buildings
    • 7 Healthcare buildings
    • 8 Buildings related to national security.
    The carbon footprint calculation according to TEK17 § 17-1 shall be based on actual use of materials.
    The quantities of building materials used can be found in different ways, the most common being getting the quantities from drawings or BIM. The quantities can also be sourced from cost calculations or taken directly from invoices based on what is ordered and used in the project.
    The carbon footprint calculation does not need to be delivered with the general permission application but shall be finished before the certificate of completion is issued, together with all other documentation related to the project. The carbon account shall be verifiable and shall be shown in the case of a revision.
    This means that there are no absolute requirements for when the carbon footprint calculation should be performed, other than that it shall include actual use of materials and the calculation shall be finished upon building completion, without having to send the carbon footprint report to the planning authority.

    Limit values for the LCA

    It does not seem probable that limit values for carbon footprint of a building will be included in the regulations in the near future (<2 years). The technical regulations are not frequently updated, and the new requirements for carbon footprint calculations was introduced on July 1st. It is assumed that limit values will be introduced in the long term (+5 years), but this is highly uncertain. 

    Methodology

    Building LCA has not been common in the Norwegian construction sector. Mostly ambitious projects have done it in order to get a certification e.g., BREEAM and FutureBuilt (described later). Another driver has been requirements set in public procurement of buildings, which more and more commonly include limit values for Carbon footprint of a building. In later years, private companies, large public real estate companies, contractor trade associations in the construction industry have been important drivers for LCA in construction. This is even more increased with the EU-Taxonomy which drives especially large public companies to get a good carbon footprint to increase their competitive advantage, through certifications like BREEAM. 
    The regulations for LCA of buildings are thus less stringent than what the large actors are doing. This is driven mainly by a fear of reducing the competitiveness for smaller actors who might not have resources to follow stringent regulations.

    BREEAM-NOR

    BREEAM-NOR certification: BREEAM certifications is managed by Building Research Establishment (BRE) in the UK, the Norwegian adaption is BREEAM-NOR (Grønn byggallianse, 2023). Today BREEAM-NOR is the most used environmental certification for new buildings and major renovations in Norway. When a building is built according to BREEAM-NOR, is shows that projects have qualities beyond the minimum requirements. BREEAM-NOR shall reflect current “best practices” in Norway and be a driver for innovation for the environment and increased sustainability. In BREEAM-NOR there are nine categories that have to be taken into account.
    BREEAM-NOR 2016: (BREEAM-NOR, 2016)
    BREEAM-NOR V.6.0: This is the newest version of BREEAM.NOR and got published in February 2022 (BREEAM-NOR, 2022). In this manual Mat 01 is the criteria for climate gas calculations of materials:
    Mat 01: absolute requirements for residential buildings, offices, schools, shops, nursing homes heated and unheated basements.
    The calculation shall include building parts 22, 23, 24, 25, 26 and 28 in NS 3451:2009. Please note that building parts 21 and 49 should not be included.
    The calculation shall include modules A1–A3, A4 and B4
    All BREEAM project minimum 20% reduction (1 point Mat 01), 30% 2 points, 40% 3 points

    FutureBuilt ZERO.

    These criteria should contribute to the achievement of the national and international objective of a low-emission society by 2050 (FutureBuilt ZERO, 2021). The criteria should be both ambitious and readily understandable, aiming to support Norway’s goal of reducing greenhouse gas emissions by 50–55% by 2030 and 90–95% by 2025, compared to the 1990 level. Figure 1 illustrates the required emissions reduction by 2050.  This figure displays greenhouse gas emissions for buildings today, current practices and current best practices, as well as projected reductions in accordance with national climate goals (Resch, et al., 2020).
    In the starting point at the curve the emissions are based on nearly zero-energy building, emissions from materials are based on the top 25% performing exemplary building and has a one-site electricity generation from solar panels covering an arear equivalent to 10% of the heated usable floor area (BRA (Resch, et al., 2020). The criteria apply per heated usable floor area (BRA)^2 over a 60-years lifespan. These criteria apply to the year of planes building completion or the year it becomes operation. To make sure that the emissions from materials and energy, there are established a maximum criterion for emissions from building material and operation energy use.
    In calculation for Built Zero buildings elements 21–29 and 49 are mandatory inclusions in the Building LCA, but it is advisable to document other building elements as well, as these may be incorporated at a later stage (FutureBuilt ZERO, 2021). The calculations rules for Built ZERO mainly follow the NS 3720 method, but there are introduced some additional elements (Resch, et al., 2020).  The sum of greenhouse gas emissions associated with buildings element 21–29 and 49 calculated for life cycle modules A1-3, A5, B2-5, B6, as well as additional modules D-energy, BC-consumptions, D-reuse, B-biogenic, B-carbon, must not exceed the red FutureBuilt curve

    Powerhouse

    Powerhouse Paris Proof is a new standard for the buildings of the future, based on the Paris Agreement’s 1.5-degree target. For more information: https://www.powerhouse.no/en/
    The standard lists maximum and total CO2 emissions per square meter, including the construction phase, energy in operation, materials, and disposal. FutureBuilt’s energy positive buildings definition is used as a basis for energy production.
    Achieving the Powerhouse Paris Proof standard will require zero-emission construction sites, climate-friendly materials, recycling, and reuse as part of the solution, in addition to renewable energy production and energy efficiency.
    To be defined as Powerhouse Paris Proof, the buildings total carbon footprint (A1-C4) must be less than the carbon budget for the specific opening year of the building. The carbon footprint budget is defined by a reference building (standard construction and energy use) for 2010 multiplied with the reduction curve for 1,5-degree target by IPCC.

    System boundaries

    The calculation period has traditionally been set to 60 years in Norway, as this is the timeframe used for building cost calculations. The calculation period in the new technical regulations is now changed to 50 years to be in line with the EU taxonomy requirement through Level(s). It is probable that 50 years calculation period will be the new standard calculation period in Norway as the requirements in TEK become more widespread. Table 6 presents the life-cycle modules in the current Norwegian methodologies.
    Table 6. Life-cycle modules (according to standard EN15978) in the current Norwegian methodologies.
    Life-cycle modules
    Norway TEK17
    Norway BREEAM-NOR-v6.0
    Norway FutureBuilt ZERO
    Norway Powerhouse
    A1-A3
    X
    Mat 01
    X
    X
    A4
    X
    Mat 01
    X
    X
    A5 waste from construction
    X
     
    X
    X
    A5 energy use construction
     
    Man 03
    X
    X
    B1
     
     
    X
    (X)
    B2
    X
    (Mat 01)
    X
    X
    B3
     
     
    X
    (X)
    B4
    X
    Mat 01
    X
    X
    B5
     
     
    X
    (X)
    B6 (operational energy)
     
    Ene 01
    X
    X
    B8 (transport of users in operation)
     
    Tra 01
     
     
    C1
     
     
     
    X
    C2
     
     
     
    X
    C3
     
     
    X
    X
    C4
     
     
     
    X
    D
     
     
    X
     
     
    According to the Norwegian standard NS3720, demolition and waste treatment of existing buildings or constructions for plot preparation are allocated to the building being demolished (C1-C4) and are not included in the carbon footprint calculation of the new building. If the purpose of the calculation is to compare different plot development alternatives, and only one solution includes demolishing the existing building, the demolition should nevertheless be included.
    Waste from future demolition (C1-C4) is not required to include according to calculations in TEK17 but is usually included in other calculations according to NS 3720 (Standard Norge, 2018), and for BREEAM-NOR, FutureBuilt and Powerhouse.
    Reporting of biogenic carbon may have a large impact for the carbon footprint calculation. This is especially important for wood-based products but is also relevant for other biogenic products. Biogenic carbon is carbon accumulated in biomass through photosynthesis from carbon dioxide in air. This is again released into the atmosphere as carbon dioxide when the biomass is incinerated or decomposed. As a standard rule, the uptake and emission of biogenic carbon throughout a building materials lifetime shall sum up to zero. NS-EN 16485:2014 (Standard Norge, 2014) gives calculation rules for emissions and uptake of biogenic carbon.
    Since uptake of biogenic carbon is included in module A1 for EPDs, the sum of GWP for A1-A3 can result in a negative value as emissions are only included in module C.
    Since the carbon footprint calculation according to TEK17 §17-1 shall not include module C, the GWP values from EPDs must be corrected to not account for biogenic carbon stored in the product. This is solved by using the mandatory indicator GWP-IOBC
    GWP-IOBC Follows the principle of instantaneous oxidation of biogenic carbon, meaning it sets storage and emission of biogenic carbon to 0 in all modules.
     in EPDs from GWP Norway. In EPDs from the international EPD system the indicator GWP-GHG gives the same effect, e.g., excluding biogenic carbon stored in the product. For EPDs following the new standard EN15804+A2:2019 the indicator “GWP, total” subtracting “GWP, biogenic” could be used, with the problem that release of biogenic methane is included in GWP, biogenic, thus omitting this impact if it is significant.

    Operational energy use calculation

    The source data for greenhouse gas calculation from energy use in operation is related to heating, cooling, ventilation, hot water, and lighting. The calculation must be carried out according to either NS 3031:2014 (Standard Norge, 2014) or SN/TS 3031:2016 (Standard Norge, 2016) or be based on actual measurements for energy consumption for the building in operation. When analysing a completed building structure, greenhouse gas calculations do not include emissions related to the production, distribution, and installation of local energy production equipment in B6, this will be reported in A1-A5. If the equipment is installed after the building is put into operation, it should be reported in B4-B5. Emissions related to local energy supply (e.g., solar panels) can be obtained from EPDs, third party-verified documentation, or reputable LCA databases. After an energy supply system is chosen, specific emission factors for specific systems and selected energy products should be applied.
    According to the Norwegian standard for Building LCA two different scenarios for electricity supply should be used. Both scenarios must be presented in the result report. Both scenarios use an average baseline of consumption mix for the last three years, but scenario 1 uses Norwegian consumption mix (~24 g CO2 eq./kWh), and scenario 2 uses European (EU28+NO) Consumption mix (~110 g CO2 eq./kWh). In both scenarios the emission factor for the grid mix is calculated using a linear function to approach near-zero emission by 2050, which is then maintained at this level unit the end of the period. In addition, the result report must indicate whether an agreement for Guarantees of Origin for purchased electricity has been made.
    For calculation of energy demand at the construction site, the Norwegian grid mix is typically used, to be in line with electricity emission factors used in most EPDs.

    Level of detail in calculating and reporting building LCA

    The main challenge in general for early-stage building LCA is the level of data detail during the given phase of the project. A lot of time is spent in converting data to the “right format”, which is often done manually through material-take-off in Solibri or another IFC-reading programme. There is a risk of error when making assumptions on what materials are included in for example “wall type 1”. The model is constantly evolving in the design phase, so there is an issue to get a complete enough version of the model before it is finished – it is nevertheless important to have enough time to extract the material quantities.
    There are also challenges with setting the right emission factor for the materials. Especially in the early phases of the project assumptions must be made for “standard” material types, when it is not known what material supplier will be used. In later phases when material suppliers are chosen, EPDs can be used. 
    Uniform reference service life of the products is also a challenge, as the EPDs often declare technical service life, even though a realistic replacement of elements happens more often than the technical service life. In general, all reference values and building LCAs should use the same service life and number of replacements for the same building type. To get a better service life, the project should need to make a compelling case for why a different service life is used.

    Accepted data sources

    According to the technical regulations (TEK) generic emission factors shall have an added impact of 25% unless such added impact is already included in the emission factor. Primarily, product specific EPDs shall be used in these calculations.
    For other building LCA methods, the data sources for generic data are not clearly defined and often an EPD representing a common product in the market is used as a proxy to generic data. For concrete the Norwegian concrete association has standard emission factors for concrete of different environmental performance which are updated every few years.
     The Norwegian Green Building Council also has a Green Material Guide which gives guidelines for standard emission factors for different material types.

    EPD-databases are the main source of emission data for building LCA. The main EPD-Programmes used which have available APIs are:

    • EPD-Norway is the Norwegian EPD-Foundation and got established in 2002 by NHO and the Federation of Norwegian Construction Industries (BNL) because business and organisations demanded environmental documentation, preferable standardised according to international standards (EPD-Norge, 2023). EPD-Norway guides business in communicating the environmental performance of their products. The EPD are created based on a life cycle analysis according to ISO 14040-14044. EPD-Digi is EPD-Norway`s digital EPD database, which is made   available to the public.
    • EPD-International
    • Environdec
    • EPD-Germany
    • Ecoinvent is a not-profit association based in Switzerland, developed supporting high-quality science-based environmental assessments (ecoinvent, 2023). The ecoinvent database is used worldwide as a background database in LCA and other environmental assessments. The newest version is ecoinvent v.3.9.
    • Concrete: standard for low emission concrete NB 37
    • Green material guide, Norwegian Green Building Council

    Many EPD systems are connected to the InData platform which has a common API for EPDs from the following EPD systems,

    • Institut Bauen und Umwelt (IBU), Germany
    • The International EPD ® System, Sweden
    • The Norwegian EPD System, Norway
    • EPD Italy
    • EPD Danmark
    The EPDs are available in a common database, but there are still some inconsistencies with use regarding use of GWP indicators. GWP factors excluding biogenic carbon are not included in the digital database. For EPDs according to EN 15804+A2 the indicator “GWP total” excluding “GWP, biogenic” could be used. There is nevertheless an issue outlined earlier that biogenic methane should be included which falls under the indicator “GWP, biogenic”.

    Building LCA tools

    Four tools are mainly used for building LCA:

    • OneClickLCA: it is a software tool and platform used for life cycle assessment (LCA), environmental product declarations (EPD), and low-carbon best practice. In the programme it is possible to choose from global generic data or manufacturer specific. Third-party verified EPDs. There is constantly being added new EPDs in the platform and it`s possible to request EPDs directly from manufactures.
    • Reduzer is both software and a platform designed to facilitate emission reducing in constructions (Reduzer, 2023). This software enables the generations of design based on available information and facilitates comparisons of different design. Reduzer also offers the capability to compare results from different calculations methods of carbon footprint, where is possible to choose which method you want and make a customised calculation method.
    • LCAByg NOR is freely available tool that can used to assess the environmental performance throughout their life cycle of both new and existing buildings (LCAbyg, 2023). This tool can be used for the assessment and documentation of the environmental performance of buildings in accordance with the requirements for greenhouse gas calculations in TEK17 and BREEAM-NOR 6.0. It is original developed in Denmark, then made a Norwegian version. EBA have developed he tool with assistance from SINTEF, Grønn Byggallianse and BUILD from Aalborg University.
    • ISY Calcus is a tool which calculate both construction cost, lifecycle costs and greenhouse gas emissions all in one tool (Norconsult, 2023). ISY Calcus generates these data in a single system, this makes it possible to analyse and optimise both environmental consideration and costs in one operation. It can be used in early-stage projects, and then develop the estimate as the project progresses. The tool is developed by Norconsult.
    Primarily Solibri model viewer or other IFC reader is used to extract material quantities. OneClickLCA has a possibility to connect to BIM. Some consultants also use self-made tools through parametric design in for instance Grasshopper in Rhino to connect LCA-data to the BIM model.

    BIM practices in Norway

    Interviewees’ background

    Two experts were interviewed. The first expert has over 40 years of experience within the building and construction sector. BIM strategist with many years of experience with developing digital building design. The second expert has worked over the past 25 years with BIM, visualisation, engineering and interaction. Expertise in standards, methodology such as VDC and SCRUM, BIM, collaboration, model-based engineering and production, GIS, information management and digital tools.

    The use of BIM

    From the interviews, it seems that BIM is widely used in all design disciplines. In practice, some 3D modelling is done in all stages of the project, although different tools might be used in the schematic design phase, for instance, Sketchup. Some chose not to call it BIM because the information part sets expectations for the details which should be included in the model. Nevertheless, all seem to be using 3D modelling to some degree, even for renovation projects and when delivering traditional 2D drawings.
    There is naturally some difference in the level of detailing in different stages. For instance, different layers of a wall might not be modelled early; the wall will only be one object. The main shafts are modelled early for the technical systems, e.g., HVAC, with more detailing later in the project. However, technical disciplines use pre-defined libraries with many details for the objects being modelled.
    Maturity of the model is the main problem. The paradox is that the model is not completely mature until the design stage is finished, and therefore other methods must be used to make LCA-based decisions in the earlier stages of the building planning, e.g., the schematic design phase.
    The main tools being used are sometimes Sketchup in the early design stages. Revit for technical, architectural and structural disciplines, and also Tekla for structural engineers. Outdoor architects use the Quadri database in Revit and Novapoint.
    Consulting Engineers Association, named Rådgivende Ingenørenes Forening (RIF) in Norwegian (RIF, 2023). RIF has an Expert Group on BIM consisting of members from different consultancy companies. Their goal is to be subject experts and to be a driving force in the development of BIM use in RIF and for its members. The group is a member of important forums for BIM and digitalisation, among other buildingSMART’s cross-disciplinary user forums. The group also holds BIM courses based on buildingSMART’s curriculum.
    The BA-Network is a network which is developed to improve collaboration and data flows in construction and infrastructure projects (ba-nettverket, 2023). The network is mainly focused on transportation and infrastructure projects; however, they are also concerned with good collaboration between building and infrastructure. BA-network organises network events to disseminate knowledge and enthusiasm.
    BuildingSMART is an international nonprofit company within the Construction, Building and infrastructure industry, which develops standards to help the entire supply chain work more efficiently and facilitates collaboration among all stakeholders (buildingSMART, 2023).  To shape the future of construction, buildingSMART strives to make use of BIM, digital twins, and data collaboration standards. BuildingSmart Norway is one of the buildingSMART international 15 national chapters.

    BIM guidelines

    The main drivers in documenting BIM practices are the large public construction companies, for instance, Statsbygg (national government buildings)
    , Sykehusbygg (public hospitals)
     and Forsvarsbygg (national defence). They have their own requirements for what should be included in their BIM model, and all companies doing modelling work for these need to follow them. There are also available API plug-ins to include these BIM requirements directly in the Revit models.
    SIMBA is a collective term that describes Statsbygg`s BIM requirements (SIMBA, 2023). Statsbygg is the central advisor to the state in construction and property matters, the client for state building projects, property manager, and property developer. These requirements describe how BIM models should be made, what information they must contain and how the information is structured. To make sure that the requirements are being enforced, the BIM model must be controlled. The newest version is SIMBA 2.1.
    Based on these requirements and national practices, a Norwegian standard has been developed. NS 8360 BIM objects for construction works (Standard Norge, 2021).  This standard is also following ISO 19650 methodology. These practices are independent of the building type, and all building types are modelled.
    The information standard ISO 19650 (Standard International, 2018b) is more and more commonly adopted in the Norwegian construction sector. But the standards developed nationally still take precedence, and even these are not always followed.

    Naming conventions

    Aside from previously mentioned standards, the following standards are relevant for building classification and naming. They are all, to some degree, being used in the Norwegian construction sector.
    ISO 23386 International standard for building information modelling and other digital processes used in construction. This standard is developed to make sure that all definitions which are needed in all BIM domains can be interoperable in tools and applications.
    ISO 23387 International standard for building information modelling (BIM). Data templates for construction objects used in the life cycle of built assets – concept or principle. This standard describes the principles and structure of data templates and is in alignment with ISO 23386.
    IFC 4.3. – is the first international standard to introduce a wide range of definitions to present a construction project in a harmonised way for the building and infrastructure industry (BuildingSMART, 2023). It is an openBIM standard for buildings and infrastructure.
    EN 3457-3:2013 is the standard classification of buildings. This standard represents the initial phase in establishing a comprehensive Norwegian system for organising information related to buildings, construction and real estate.
    prEN 17473 Product data templates, for products and systems used in construction works, stored in a data dictionary framework – Part 2: Specification of Product data templates based on harmonised technical specifications under the Construction Products Regulation (CPR).
    For actual building products, considerable resources have been used to develop product data templates (PDTs) according to ISO 23386 and ISO 23387. These are being adopted by the construction industry, but there is still some pushback from the users who prefer doing it the way they have always done it.

    Quantity take-off

    The main tool being used seems to be Solibri Model Viewer, and similar IFC readers, with IFC being the main format for data transfer between disciplines. During data transfer, the person exporting to IFC format chooses what data shall be transferred. This means that some information is lost in data transfer, but this is not necessarily an issue as long as predefined requirements are set and met, and there is no need to import the IFC file back into the modelling programme.

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