The climate declaration must be submitted to achieve the building permit. If there are major changes between the plan used for the initial calculations and the realised building, the updated calculations must be delivered after the building is finished. The differences might arise from changes in plans, materials or more accurate knowledge of the products used (EPDs of products used instead of the general data).
The limit values will be taken into use as the law regarding the climate declaration will enter into force. They have not been defined yet, but the collection of the voluntary carbon footprint calculation results has been done to get an understanding of the baseline level.
Methodology
The general guidelines behind all Nordic methods are EN15978 standard and Level(s) framework, which leaves a lot of room for specification to create calculation methods. In Finland, the method for the normative calculations for building permits was first introduced in 2019. The method will be updated after agreeing on the details of the regulation, which might still change.
The results of the LCA studies of building projects are not collected systematically at the moment, but Helsinki, for example, has already introduced its limit values and received data through the building permit process. In smaller cities, the LCA calculation might not be as common. The same applies to construction companies: the bigger companies have already adapted the routine of calculating the building LCA, whereas smaller companies are not doing it as often. The factors driving the calculation of building LCA are partly preparation for the coming regulation and partly companies’ environmental strategies.
System boundaries
For the normative LCA calculation in Finland, the building and the building site are considered, but for example, the temporary premises and scaffolding are left out. The calculation is made for a 50-year period and includes modules A1-5, B4, B6, C1-4 and D1-6. Module D needs to be reported separately and is not subtracted from the carbon footprint of the other modules.
Operational energy use calculation
The energy use has to be calculated based on the energy efficiency of the building. For the emissions of different energy forms, such as electricity, district heating or fossil fuels, there is a table in the “Method for the whole life carbon assessment of buildings”. The table is based on the assumptions arising from research that the energy in Finland will gradually get decarbonised.
Level of detail in calculating and reporting building LCA
Assumptions are needed in all future modules. In Finland, the information for modules A4, A5, B4, C and D can be taken from CO2data.fi or if the information is available in EPDs, this information can be used for B4, C and D modules. For the construction operations A5 and the transports A4 and C2, the realised energy use and transports can be calculated with the emission data from the CO2data.fi or EPDs. If the general data is used, the result is also general, and the results are more accurate when the real data is used.
Accepted data sources
In Finland, the accepted data sources for the normative LCA calculations are the national emission database and verified EPDs. For the emission database, there are APIs available and active development work is continuing to make the database suitable for normative use. For the data in EPDs the digital accessibility is still very low. There are EPD databases with machine-readable EPDs and those can be accessed by API but finding automatically correct EPD is problematic as there are different product identifiers that are used in product data management in business processes. They are also exceptions at the moment and most commonly EPDs are available as pdfs.
Building LCA tools
The most common way of calculating the building’s LCA at the moment is importing the bill of quantities from a BIM model to OneClickLCA-tool. Besides this, there are a number of other tools being used. Ministry of Environment has prepared an Excel tool for the calculation purposes. The challenge with an Excel tool is to transfer all the parts of the building manually from other software.
BIM practices in Finland
Interviewees’ background
Four BIM experts were interviewed with different competence backgrounds. The first expert (BIM-specialist 1) had long experience in using IFC data for production planning, which requires quantity take-off from model and mapping quantity items with production data for, e.g., scheduling. The second specialist (BIM-specialist 2) was BIM software developer with over 20 years expertise in IFC standardisation, BIM coordination and IFC-software development. The third specialist (BIM-specialist 3) had worked over 30 years in quantity take-off and was the quantity take-of consultancy service manager. He was involved in developing and implementing BIM-based quantity take-off. The fourth specialist (BIM-specialist 4) was not a BIM-specialist but a developer of software for estimating costs and LCA of a building with a computational model that produces quantities of structures and systems by client needs of spaces or other usage information.
The use of BIM
In Finland, BIM is used widely in design and construction. Practically all multistorey residential buildings, public, commercial, and industrial buildings are modelled. Some smaller buildings and buildings outside of cities may be, in some cases, designed in 2D (BIM-specialist 2). The BIM usage in renovation is not as comprehensive as in new construction. Laser scanning is used for producing inventory models of existing buildings, fully or partially, in bigger or specific renovation projects. Inventory models are used for BIM-based design. The inventory models and BIM-based design are seldom used in typical residential building renovations.
In BIM-based design projects, all disciplines, including architectural, structural, HVAC, and electrical, models are created. Models cover the whole building, including all repetitive floors modelled separately. The level of detail of modelled structures and components is fairly well established in practice in different design phases. There is no clear level of detail (LOD) definitions for the phases, and there are some differences based on company practices and clients’ demands.
In Finland, architects are using Archicad and Revit. Structural designers mainly use Tekla Structures for general structural design and in detailing concrete and steel structures, but Revit is also used for structural design. MEP designers use mostly MagiCAD for Revit/Autocad and Cadmatic, which is often used for electrical design. Solibri Model Checker (SMC) is most used for combining and coordinating the discipline-specific models that are imported in SCM in IFC format.
Sharing the models between disciplines is based on IFC, currently in 2x3 version. Sharing models is used mostly for coordinating and clash detection by BIM coordinators (BIM-specialist 2). In construction projects, there is usually an appointed consultant for BIM coordination even though legal design coordination responsibility is on the main designer (architect).
Finland has approved a new Building Act that will enter into force on 1.1.2025. There is a requirement that building design for building permit application must be provided as a building information model (BIM) or in machine-readable format. In practice, this will mean building permit application with the IFC model in most cases. This will affect practices, especially in architectural modelling, as the building permit is applied based on architectural design. Preparations for BIM-based building permitting have been done in the municipalities’ common Rava3Pro development project, and requirements and data contents for permitting BIM have been defined and will be detailed later. The new Building Act also requires LCA calculation for permitting. Currently (October 2023), new decrees for defining official requirements for BIM-based permitting and the climate declaration are under development.
The main community in Finland for BIM-related developments and harmonisation is buildingSMART Finland (bSF), which is a chapter of buildingSMART International. Operations of bSF are organised in Rakennnustietomalli Oy, which is a subsidiary in a group of companies owned by the foundation Rakennustietosäätiö. bSF has four major working groups for buildings, infra, cities and competence & skills.
Due to the above-mentioned new regulation, other development groups are working on BIM and digitalisation topics related to authorities’ work at national and municipal levels, e.g., Rava3Pro and previous building permit (Rava)-projects. The Ministry of Environment has also organised an ongoing project, started in 2019, to develop the interoperability of the built environment information. The project is not directly providing methods or guidance for BIM-based interoperability but creating high-level data models and vocabularies that would also be utilised in BIM-based data exchange. All developed data definitions are documented on the Web to be used as public digital data dictionaries in the future to increase semantic interoperability in the domain.
The new regulation changes also building registries and archiving. Under development is a national-level registry for building permit data and city plans. This data is currently stored at a municipal level, and only main building and dwelling information is stored in the national building registry. All design disciplines’ IFC models are required to be stored in this central registry in the handover phase of a construction project. Also, The National Archives of Finland has made 2023 an official decision to approve the IFC format for long-term archiving. The approval covers, at this point, the IFC version 4.0.2.1.
BIM guidelines
BIM modelling in Finland has been guided at the national level since 2012. Common BIM Requirements (COBIM) are presented in 13 parts for different design disciplines and use cases. Even though those were named “requirements”, in practice, those are more like guidance, but some clients’ have set selected content of those in design contract requirements. COBIM guidance has harmonised, at some level, what to model in different design phases and had a real impact on modelling practices. The COBIM documentation has not been updated, and buildingSMART Finland has launched a development project in 2022 to create new guidance for modelling and BIM usage in the domain. Participating organisations fund the development.
Large public client organisations and some private clients and developers have their own documented BIM requirements and guidance for the designers. Senate Properties, owner of the buildings used by the state, prepared the first general BIM requirements and guidance in 2008. The current requirements typically include a procedure to create a project-specific plan for BIM modelling, and usually, the BIM coordinator-consultant prepares the plan and is responsible for the follow-up of the implementation. Beyond the current approach, there are first indications for a more formal approach to managing modelling content. Those are based on the ISO 19650 standard series for managing information and BIM in buildings and civil engineering works.
In practice, the modelling has been concentrating on managing the 3D geometry and visual quality of the models. This has enabled better coordination of different disciplines’ designs, clash detection, and management of common coordinates in the models. However, the alphanumeric information content of the objects in the models has more variability, and information may be ambiguous or just missing. This is due to missing detailed requirements, and the client’s general requirements are considered as guidance (BIM-specialist 2).
In detailed design, the modelling provides added value to stakeholders. Large prefabricators in Finland use detailed BIM data in their concrete or steel component production and supply chain management. HVAC modelling software enables simulations with detailed system models, like ventilation systems, but this intelligence is lost in IFC-export.
Naming conventions
In Finnish design practice, the main structures of the building are identified with established project-specific naming conventions referring to the structure type (like an external wall) and a number identifying the type. Designers also use in detailed design other national naming and coding conventions for different components like windows, doors or precast components. These identification practices are not fully standardised, and designers apply those according to their needs at the project level.
The Project classification codes of the national Talo-2000 system are not used systematically in architectural and structural BIM for classifying structures or components. The Talo-2000 system also contains Building product classification codes that are sometimes used in architectural models for classifying materials and components, but this depends on company practices and often all materials or products have not been classified.
The naming of the products and material layers in the architectural model is based on a typical plain language description that is understandable by human professionals, but naming is not standardised or harmonised in the domain. Also, there might be some variability in expressions even in the same project, and some naming might be missing. Sometimes, even material layer dimensions may be missing. In general, fully automated semantic identification of the materials and products is not reliable, and some semi-automated mapping to emission data is usually needed.
The Rava3Pro development project has defined national IFC custom property sets and properties and allowed enumerated coding of values to enable improved semantic interpretation of IFC model data contents and identifying components. Those developments include, e.g., how to define building type in IFC data with officially required codes. There is the same kind of approach for defining room usage types or common naming for MEP components. The allowed values for these properties will be published in a national Web-based data dictionary. Also, the usage of the buildingSMART Data Dictionary for publishing this coding is under evaluation.
In Finland, the regulation for BIM-based building permitting and normative LCA are under development until 2025, when the new Building Act comes into force. The BIM-based permitting will affect the modelling practices in the domain, but it is still unclear whether there will be official modelling requirements supporting BIM-based normative LCA.
In Finland, LCA is already calculated in many projects in the design phase. The specific LCA consultant usually calculates with OneClickLCA as it provides several emission data sources. The current guidance for normative LCA allows the use of emission data sources, either national emission database (CO2data.fi) or EPD data (this guidance is not yet approved). Only in a few cases the designer selects a commercial product in design, so most of the calculation will be done with national conservative data. The national database includes some options to select, e.g., low-emission concrete in design. Still, in general, there is no other possibility that the designer could set a limit value for components or materials for the contractor to reach as any other design requirement.
Quantity take-off
IFC-based quantity take-off is done in Finland with BIM software like Solibri Model Checker or Simplebim, or with some cost estimation software like Tocoman BIM3 or RIB iTWO, which have the capability to extract quantity information from BIM. It is also possible to do quantity take-off directly from the native BIM software.
The interviewed specialists (BIM specialist 2 & 3) compared LCA calculation to cost estimation. The contractor’s cost estimation is based on cost data of resources like different materials. In an advanced method, the quantities are taken off at the building structure or component level and attached to predefined cost structures in the company’s cost estimation software. The cost structure defines how much material is needed per structure or component unit. The cost estimation system contains material cost data per material unit to calculate the costs of the structure or component. Besides the cost data, the material item can have emission data to calculate LCA based on the same quantity information as cost estimation.
In this quantity take-off procedure, the detailed material data possibly defined in the IFC is not calculated. The cost estimation procedure is not a fully automatic workflow and requires manual mapping to detailed cost items. Some companies use Simplebim to re-process the IFC file to make this mapping semi-automatic. In this process, the company-specific identifiers are added to the IFC file with Simplebim’s functionality of modifying IFC data with user-defined rules, and as a result of the process, some quantities can be automatically mapped to cost items.
Quantity take-off from IFC data is based on reading quantity property sets where native software exports the calculated values. Another approach is that above-mentioned software imports IFC data and can calculate quantities by the geometry of the objects.
The input data format in the abovementioned software is IFC, as the software can handle IFC data for the quantity take-off. In Finland, the most used LCA software, OneClickLCA, can import quantity data in MS Exel and gbXML formats. OneClickLCA also has plugins for several BIM authoring software, enabling designers to produce LCA for own discipline in the native software.
The contractor’s cost estimation is based on a more detailed level of detail of design that is required for building permit application. There are other cost estimation services that clients are applying for budgeting in the earlier phase. For example, Haahtela TVD software can produce a budget for a building with simulated quantities based on the needs of different spaces in the building, and LCA calculation will be added to the service. When the design is developed, the input for simulation will be detailed, and the budget will be updated.
References
Finnish Ministry of the Environment. (2019). Method for the whole life carbon assessment of buildings. Publications of the Ministry of the Environment 2019:23.
Häkkinen, T. (2022). LCA database for building products, services, and systems - Description of the content and working methods (pp. 1–54). Reports of the Finnish Environment Institute 48 | 2022.
Kuittinen, M., & Häkkinen, T. (2020). Reduced carbon footprints of buildings: new Finnish standards and assessments. Buildings and Cities, 1(1), 182–197.
https://doi.org/10.5334/bc.30