SUSTAINABLE BUILDING AND BIM. Tarja HÅKKINEN Dr 1 Arto KIVINIEMI Dr 2

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1 SUSTAINABLE BUILDING AND BIM Tarja HÅKKINEN Dr 1 Arto KIVINIEMI Dr 2 1 VTT Technical Research Centre of Finland, Espoo, Finland, tarja.hakkinen@vtt.fi 2 VTT Technical Research Centre of Finland, Espoo, Finland, arto.kiviniemi@vtt.fi Keywords: sustainable building, building information modelling, information management, environmental assessment tools Summary Aspects of sustainable building include the aspects of building performance, environmental, economic, and social impacts. Sustainable design and life cycle (LC) management of buildings need new type of information compared to traditional building processes. Because of the abundance of required information, efficient information-technological solutions are needed. Building Information Modelling (BIM) is becoming momentous in AEC industry and real estate sector to share and exchange information among stakeholders, and the use of BIM is currently emerging around the world. BIM should also be able to support the supply, integration and management of information throughout the building LC. LC information can be given in terms of product data and different kinds of assessment and simulation models. With help of this information, aspects of energy, indoor environment, environmental impacts, LC costs and service life should be able to be considered in design and maintenance. BIM in its different stages should be provided with all initial information that is needed in the implementation of LC methods. Additionally, the results of assessments should be integrated with the different stages of BIMs in terms of indicators and guidelines. The paper discusses some of the problems of integrating LC information with BIM and highlights the expected benefits. 1. Sustainable building According ISO TS (ISO 2006a), sustainable construction brings about the required performance with the least unfavourable environmental impact, while encouraging economic, social and cultural improvement at a local, regional and global level. The concept of sustainable building is wide. As summarised by Shelborn et al. (2006), one of the key issues in making construction projects more sustainable is overcoming the obstacles of capturing and managing the knowledge needed by project teams to affect such change. There is still a need for a structured approach for the implementation of sustainability practices and methods within construction projects. Indicators, checklists and assessment tools for sustainability in construction are available, but these do not provide a comprehensive solution. Design tools for sustainable building should be able to simultaneously address a number of performance aspects and integrate the information into the design environment. Kohler and Lützkendorf (2002) mention six criteria for integrated building life-cycle assessment: 1) adaptability to building life cycles, different actors and decision levels, 2) adaptability to different types of impacts, 3) consideration of absolute and relative targets, 4) relying on explicit physical framework, 5) linkage of needed data with normal professional working environment, 6) scaling of needed data with process phases and availability of accurate information. An important approach to seek solutions for the problems of sustainable building is with help of information management, and there integrated Building Information Modelling (BIM) offers a potential. The scope of this paper is to study the management of sustainable building with help of BIM from the view point of: Assessment of environmental impacts Assessment of energy consumption Service life design Maintenance manual Optimization of building refurbishment Sustainability rating of buildings The starting point for this paper is that life cycle assessment methods and sustainability indicators are able to support sustainable building and construction in requirement setting and design for required performance and life cycle. Sustainable building assessment methods are believed to support sustainable building, because those enable the comparison of alternative solutions and thus enable the consideration of sustainability aspects in decision making. However, the use of these methods in building planning and in 679 Authors Index Program Index

2 design for sustainable buildings is problematic, because a lot of data is needed in order to be able to assess alternative solutions. Thus the assessment is often done only for the final solution instead of collecting data for design options. Design for sustainable buildings needs integrated methods which should provide the process with easy-to-use and comprehensive product information and integrated calculation and simulation facilities that enable the comparison of design options and the effect of changes automatically or with reasonable extra work (Häkkinen & Pulakka 2007). Furthermore, even more problematic is to understand, how sustainability aspects could be considered already in the preliminary planning process where decisive decisions are already done. It would be important to integrate environmental indicators and data to the design process in order to rationalise assessment and thus also to support planning and design for sustainable building. The premise of this paper is that this can be done with help of BIM. Integrated building information modelling is becoming very important in AEC industry and real estate sector and the use of BIM is currently emerging around the world (GSA 2007, NBIMS 2007, Senate Properties 2007, Statsbygg 2007). 2. Building Information Models BIM denotes the creation and use of coordinated, consistent, computable information about a building project during design, construction and building operation and management. BIM can also be defined as the collection of objects that describe a building (Lima and Hans 2007). Software applications of BIM work with objects, which represent all elements of building construction including physical components, spaces, processes, actors involved, and relationships between these objects. In most cases the complete design information of a building consists of several domain specific design BIMs, such as architectural, structural. HVAC, and electrical BIM. Integrated BIM is a combination of these individual BIMs. In this paper the term BIM is used to describe the integrated BIM; total repository of all BIMs containing the information of a building. BIM covers not only geometry, spatial relationships and geographic information and quantities, but also properties of building components. Quantities and shared properties of materials can be extracted. It can be used as the source of information for the analyses of the solution as well as to store the results of analyses. BIM can be used to represent the entire life cycle of the building including the processes of construction and facility operation. Because of enabling the sharing of information and because of working with objects, BIM could significantly support the management of information needed in design for sustainable building. Important questions are how to integrate and what is the degree of linkage or inclusion of different data bases and tools with domain specific BIMs. In most cases, the BIM should offer a framework and the source of information concerning the design solution, while the specific assessment and simulation models and the needed background data (for example the environmental data of products) are not embedded but linked with help of identities and interfaces (Häkkinen 2007). The usage of BIM in sustainable building and construction depends on the implementation of BIM and this varies in different countries. The Finnish Senate Properties is one of the forerunners in mobilizing BIM, and this paper refers to the guidelines "BIM Requirements 2007 in different phases of the design and construction process" adopted by Senate Properties. The guidelines have been formulated by Kiviniemi et al. (2007). Senate Properties is a government owned enterprise that is responsible for managing the Finnish state's property assets and for letting premises. The building stock comprises university, office, research, cultural and other buildings (Senate Properties 2008). According to the Senate Properties guidelines, the different phases of construction projects and related BIMs are the following: Analysis of needs and objectives Requirement model: Project requirements and requirements of the authorities Design of alternatives Alternative mass and spatial models Early design Architectural model, structural model, HVAC model, Electrical model Detailed design Architectural model, structural model, HVAC model, Electrical model Bidding phase Approved detailed design and Construction model Construction and commissioning Construction model and As-built model Facility management and maintenance Maintenance model 3. Sustainable building standardisation Standardisation of sustainable building methodologies is necessary in order to integrate sustainable building aspects with BIM processes. It is necessary to standardise the definitions and semantics of this information. The general principles on life cycle assessment of products and services have been agreed upon and made public with help of ISO standardization. In addition to general methodologies, applied methods for building products are being standardized by ISO. There is also a European process going on, which aims at the 680 Authors Index Program Index

3 development of harmonized life-cycle standards for buildings and building products. ISO TC 59 SC 17 "sustainability in building construction" is working on several documents: IS0 CD General Principles; IS0/PTR Terminology; IS0 /TS Sustainability indicators Part 1: framework for the development of indicators for buildings; ISO DIS Environmental declarations of building products; and ISO DTS Environmental performance of construction works Part 1- Buildings. ISO has also leaded the process of developing standards for service life planning. ISO (ISO 2000), ISO (ISO 2001) and ISO/DIS (ISO 2006b) give general principles for service life planning, describe service life prediction procedures and give guidelines for reference service life. Standard ISO presents a basic methodology in the area of service life design, but the methodology requires considerable knowledge about the age and degradation of components and materials. From the view point of information management, the above mentioned standards rather work with principle methodologies. In order to enable integration of sustainable building methodologies with BIM, the definitions of information contents should be further developed. Also the specifications for data representations that have exact representation syntax which could be made use by software are missing. Sustainability in construction is also studied at European level within the CEN TC 350 "Sustainability of construction work". This TC deals with the aspects of sustainability at the levels of products and buildings. Aspects especially considered include environment, health and comfort, and life cycle cost. CEN/TC 350 will develop voluntary horizontal standardised methods for the assessment of the environmental performance of new and existing buildings and for the environmental product declaration of construction products, in the framework of the integrated performance of buildings. The becoming standards will be relevant for the assessment of buildings over its life cycle. The results from the standards mandated by the M/330 (energy performance directive) will be integrated into the assessment of the environmental performance of buildings in the framework of integrated performance of buildings. On the basis of the EC standardisation mandate M/330 EN CEN is developing methodologies for the calculation of the energy uses and losses for heating and cooling, ventilation, domestic hot water, lighting, natural lighting, passive solar systems, passive cooling, position and orientation, automation and controls of buildings, and auxiliary installations necessary for maintaining a comfortable indoor environment of buildings. 4. IFC IFCs (abbreviation is originally based on the terms Industry Foundation Classes) aim at providing an open definition for data structures to capture and exchange information (IFC 2007). The development, maintenance and implementation of IFC include to the purposes of the buildingsmart initiative of the International Alliance for Interoperability (IAI). The purpose of IFC within buildingsmart is "enabling interoperability between AEC/FM software applications" (International Council of the IAI in November 2006). IFCs express common agreements on the content, structure and constraints of information to be shared and exchanged by several participants in construction and facility management projects using different software applications. The result is a single, integrated schema representing the common exchange requirements among software applications used in construction and facility management processes (Lima and Hans 2007). Although sustainable building related information has not yet been agreed on the level of IFCs, the use of BIM could strengthen and rationalize the management of sustainable building. IFC incorporates a mechanism called Property Sets which allows information publisher to allocate new properties to an object. This enables IFC to be used for representing also product specific information. For example the environmental assessment of a design solution can be supported with help of BIM by attaching environmental information to BIM objects (defined by IFCs) via the Property set mechanism or simply with linking the object to external data bases, whereas the existing sustainability standards can be made use of. This is further discussed in sections 5.3 and Integration of sustainable building tasks with BIMs 5.1 Introduction There are different solutions for integrating life-cycle analysis software and BIM. These include separate software solutions that are able to use file exchange with BIM or that can be integrated with a BIM server using a specific API. The analysis software can then have its own library for those pieces of information that are not included in BIM. The analysis software could also be implemented by programming new functionality to BIM software. An intermediate solution for these is the integration with help of parametric formats (e.g. GDL) that allow representing not only product information but also calculations used in analyses (Siltanen et al. 2008). This paper deals with the needed contents of product information assuming that a separate software solution connected to BIM is the most likely in terms of easiness to realise and use. VTT has also developed a prototype software solution which uses design information represented by IFC together with separate product information represented in PMO ontology and calculates environmental results by combining the effects of different building elements (Siltanen et al. 2008). 681 Authors Index Program Index

4 5.2 Service life design Service life design needs information about the age behaviour of building elements and components. As defined by ISO 15686, this is information about the effect of different parameters on service life; these parameters include for example the quality of workmanship, quality of materials, building structure and details, environmental conditions, user conditions and quality of care and maintenance. Service life prediction methods have been developed for construction products which are exposed to weather conditions (for example Shohet et al. (2002) and ENNUS (2006)). There is a growing awareness worldwide about the importance of the maintenance of constructed facilities as shown by Shohet et al. (2002) and about the significance of maintenance from the view point of sustainable building as summarised by Häkkinen, Vesikari and Pulakka (2007). One of the most important parameters affecting the efficiency of maintenance management is the precision and the reliability of the predicted service life of building components. ENNUS -programmes support service life assessment of building structures (Nilsson, Vares and Vesikari 2007). The programmes help designers to determine parameters that affect the service life of a building structure and to predict service life in accordance with the factor method presented in ISO These parameters include materials, details, assembling, outdoor and indoor conditions, use conditions, and care and maintenance. Service life assessment methods support the design for required service life the better the more simultaneously the assessment can be done with the very design process. This can be supported by BIM. When integrating service life assessment with BIM, the initial data needed for defining the values of parameters should be available through the properties of the model or with help of integrated databases. Part of the needed data could be made available with help of an integrated database; this may concern for example material properties. However, also the design solution itself affects service life. Thus for example the structural model should include all information about the quality of structures that is needed as initial information for the service life assessment of structures. The structural model software should support the designer to define the structural parameters needed in the assessment of service life. The assessment software itself can remain a separate tool that is compatible with the model. The interfaces can be made by converting native data formats into IFC representations. In the case of ENNUS software described in (Häkkinen and Vares 2007) the integration of the ENNUS tool with BIM was done by converting XML file produced by standard Excel methods to IFC (Fig. 1 and 2). The results of the assessment for different building parts and systems should be imported as service life indicators to BIM. The formats of information should follow the definitions given in standards dealing with service life planning. Even applications using relatively simple data structures (e.g., service life assessment tool ENNUS is a simple Excel spreadsheet) benefit from the ability to utilise BIM. BIM can be used in this case for transferring data between life cycle phases, as well as getting initial information from the building information model. 5.3 Environmental assessment The basic principles and declaration formats of environmental assessment in terms of LCI or LCA have been agreed upon with help of standardisation processes. The environmental standards provide the needed definitions for the contents of environmental information. The building level assessment can be done by summing up the product level environmental profiles and by considering the bill of quantities. Information needed from BIM includes data about properties and quantities of different components and elements. In order to make the environmental assessment for a design or for a part of a design, this information should be linked to a database that includes the environmental profiles of building components and elements. The environmental assessment of a building can be integrated to BIM similarly as cost assessment is already done at present. The integration requires that product specific and energy related environmental profiles are available, for example, in the form of an XML database. The final result from assessment should be enclosed as environmental impact indicators to BIM (design model). According to ISO TS an environmental indicator of a building addresses an environmental aspect either in terms of loadings or impacts. Environmental loadings are the use of resources and the production of waste, odours, noise and harmful emissions to land, water and air. Different kind of environmental information is needed in different stages of the process. During the design phase relevant generic environmental information should be available. This information should describe the average environmental performance of products without being producer specific information. Generic information should be replaced by product and producer specific information in building construction phase, when the contractor wants to analyse the importance of individual product choices and store the environmental indicators to the as-built model. Environmental information may also include instructions for the building use and final disposal. This includes information about indoor emissions of building products and instructions for recycling. The integration of this information with BIM can be dealt with similarly as the care and maintenance information presented in section Authors Index Program Index

5 Figure 1 Information flows between ENNUS Spreadsheet and BIM. Figure 2 Implementation of the interface between building information models and ENNUS. 5.4 Energy consumption estimate The initial data needed in design for energy efficiency includes information about local environmental conditions, technical performance and capacity of building elements and HVAC units and systems, position of the building in the building lot, spaces, arrangement of spaces, and intended user profiles. Depending on the complexity of the design and the needed level of accuracy of the assessment, the amount of data needed may be extensive. Different kinds of assessment and simulation methods and tools are available for the assessment of energy consumption of buildings. In order to enable the energy consumption assessment with help of BIM, 1) the model should provide all data needed in the calculations and 2) there should be a suitable interface between the model and the assessment software. The product related information needed in calculations does not need to be included in the model (as attribute data of objects) but it can be integrated data collected into a compatible database and linked with the model. Probably the best solution is that the assessment is not done within the model but with help of a software solution that is compatible with the model. The results of the assessment should be imported as energy-efficiency indicators of the design model and correspondingly later as indicators of the later stages of BIM. These indicators should follow the formats and expressions (units etc.) agreed upon in standardisation. Similar conclusions have also been done by Morrissey et al (2004) when they analyse the assessment of building performance within BIM. Analysis will be achieved by querying an archive of performance objectives and performance metrics that are programmed within the BIM. Once the user has selected the performance metrics, a critical analysis may be preformed for all related design decisions and management operations. This leads to large sets of data that must be elicited at various stages and from various sources. Storage in a single IFC database would lead to a model that would be oversized and unmanageable. Performance metric data should be separated from the main model with storage occurring in XML files. The XML files should be referenced within the BIM and their associated sets of data may be elicited from a database in order to analyse the performance of the building. 683 Authors Index Program Index

6 5.5 Maintenance manual Building maintenance needs system-specifically grouped and scheduled information of all care and maintenance measures. This information should be given in terms of recommendations and instructions and formulated during design and construction. For example the Finnish building regulations require the provision of care and maintenance information in all significant building projects. In order to support maintenance management, this information should also be updated during the use and maintenance phases of the building. Building refurbishment needs information on realised building solutions and information about the requirements concerning the handling and treatment of products to be demolished, surface treated etc. When the optimum maintenance and refurbishment processes (both in terms of quality of measures and scheduling of those measures) are sought, same kind of information about the age behaviour of different building elements is needed as within service-life design. Additionally, information about costs of alternative measures is required. VTT have proposed simple methods for sharing and integrating product-specific instructions-type-ofinformation with BIM (Siltanen in Häkkinen et al and Heinonen in Häkkinen et all. 2007). A framework for a web browser (Fig. 3) based database was created where manufacturers can store all product specific service life information. The service life information was defined with using XML description language. The project suggested that the process could operate in such a way that the concept-developer requires all the suppliers of the concept to include service life information into the database with help of which the compiler of the maintenance information collects and arranges the building information to form an organised and scheduled product information set for care and maintenance. The maintenance model should be provided with methods and tools with help of which product specific maintenance information can be arranged and collected as building system specific information. The contents of this information should enable the effective implementation of maintenance considering the different periods and types of inspections, care, repair and renewals. Figure 3 LifePlan database system. 5.6 Optimization on building refurbishment Especially the managers of municipal and state infrastructure are realising the need for effective tools to manage the large asset base. Decision support tools are needed in order to support understanding and decisions on its value, condition, remaining service life, needed maintenance and optimal scheduling of operations. For example Söderqvist and Vesikari (2006), Bucher and Frangopol (2006) and Vanier (2001) have introduced methods for the optimisation of lifetime maintenance of buildings. MaintenanceMan is a tool, which supports the optimization of building refurbishment measures (Vesikari 2008). The tool uses service life models with help of which it is possible to predict the service life of the modules. The tool allows studies at different risk levels. The optimization criteria are life cycle costs (LCC) and environmental impacts. MaintenaceMan works on modular basis so that the building is divided into structural parts or modules. 684 Authors Index Program Index

7 In order to rationalize the use of these kinds of tools in the design of refurbishment options, the maintenance model should include the needed initial data, and correspondingly the design model software and the construction model software should support the designers to provide all needed initial data to the model. This includes information about materials, structures and environmental conditions. Additionally, the maintenance model should support the maintenance managers to update this information. The optimization also needs information about LCCs. This should be available through a separate integrated database, because it is both product specific and user specific information. If the results of optimization (the favourable maintenance and refurbishment strategies and their life cycle costs) were wished to be used as guidelines for future measures, this information should be imported to the maintenance model. 5.7 Sustainable building rating systems and their relation to BIM Sustainable building rating systems have been developed in international cooperation and nationally in a number of countries all over the world. The majority of the existing environmental assessment methods of buildings evaluate environmental performance of buildings relative to explicitly declared or implicit benchmarks (Cole 2005). Typically, the environmental performance is described with help of indicators which try to express both the environmental impacts as well as other performance aspects such as indoor conditions. Methods which are widely well-known are for example the BREEAM (2008) (UK), LEED (2008) (USA) and GB Tool (Kimberly et al. 2006). The point of view has gradually widened from sole environmental assessment to overall assessment of sustainability aspects of buildings. LCI/LCA approaches are partly being adopted into the environmental rating systems (for example in the German (Schminke 2008), Finnish (PromisE 2008) and Australian systems (GREEN STAR 2008)) to deal with the environmental impacts of buildings. However, the overall sustainability of a building does not only depend on the direct environmental loadings induced by the building and its use, but also on the quality of the building as a place to live and work, accessibility and interface with surroundings, quality of process (for example the participation of all concerned, probability of non-desired risks). The potential of rating systems to support sustainable building design and sustainable refurbishment of buildings would be improved, if the systems were integrated with BIMs. This would require that the BIM processes supported the determination of the building specific values for the indicators and calculation of the final results with reference to given benchmarks. With regard to LCI/LCA related indicators and indicators that are based on the characteristics of building products and energy-efficiency indicators, the determination of indicators' values can be based on the principles described in sections 5.3 and 5.4. However, with regard to some indicators - like accessibility, adaptability - the development of a specific model-checking software solution might be the best solution. 6. Conclusions Tools of LCI/LCA assessment, energy consumption assessment, service life assessment, maintenance manual, optimization of refurbishment and sustainability rating are important methods in design for sustainable buildings and in sustainable use and refurbishment of buildings. The use of these methods requires the availability of tools and a lot of additional information compared to a traditional building process. In order to rationalize the use of these methods and to support the use of methods during the design processes, the methods should be integrated with BIM processes. This paper describes the data contents related to different assessment methods and discusses the principal solutions how to integrate the methods and the required data with BIM in the different stages of building process. References BREEAM Bucher, Christian, & Frangopol, Dan M Optimization of lifetime maintenance strategies for deteriorating structures considering probabilities of violating safety, condition, and cost thresholds. Probabilistic engineering Mechanics 21 (2006). Pp. 1-8 Cole, Raymond, J Building environmental assessment methods: redefining intentions and roles. Building research and information. 35(5), ENNUS ENNUS methods for service life estimation of roofs and outdoor walls. VTT Materials and Building. GREEN STAR GSA BIM requirements. In: Häkkinen, Tarja & Pulakka, Sakari Use of LC guides in open building manufacturing. In: Open Building Manufacturing: Core Concepts and Industrial Requirements. Ed. Katzi, Sami. Häkkinen, Tarja Sustainable building related new demands for product information and product model based design. ITcon, Vol. 12, pp Häkkinen, Tarja and Vares, Sirje Whole-life optimization of buildings and BIMs. In: Häkkinen, T. et al. VTT Research Notes VTT. Espoo (2007), Authors Index Program Index

8 Häkkinen, Tarja, Vesikari, Erkki and Pulakka, Sakari Sustainable management of buildings Sustainable building conference in Lisbon (SB07), September, p. Häkkinen, T., Vares, S., Huovila, P., Vesikari, E., Porkka, J., Nilsson, L-O., Togerö, Å., Jonsson, C., Suber, K., Andersson, R., Larsson, R. & Nuorkivi, I Whole-life optimization of buildings and BIMs. VTT Research Notes VTT. Espoo, 207 p. Coding of prototypes made by Ilkka Heinonen. Häkkinen, Tarja, Vares, Sirje & Siltanen, Pekka Service Life Information of Building Products. (In Finnish.) VTT Research reports Espoo: VTT. IFC IFC specifications. In: ISO :2000. Buildings and constructed assets Service life planning Part 1: General principles. ISO :2001. Buildings and constructed assets Service life planning Part 2: Service life prediction procedures. ISO. 2006a. ISO TS 21929, Building Construction Sustainability in Building Construction Sustainability Indicators Part 1 Framework for the Development of Indicators for Buildings. ISO 2006b. ISO/DIS :2006. Buildings and constructed assets Service life planning Part 8: Reference service life and service life estimation Kimberly R. Bunz, Gregor P., Henze, P.E. and Dale K. Tiller Survey of Sustainable Building Design Practices in North America, Europe, and Asia. Journal of Architectural Engineering, Vol. 12, No. 1, Kiviniemi, Arto, Rekola, Mirkka, Kojima, Jun, Koppinen, Tiina, Mäkeläinen, Tarja, Belloni, Kaisa, Kulusjärvi, Heikki, Hietanen, Jiri BIM Requirements 2007 in Different Phases of the Design and Construction Process. In: Kohler, N. & Lützkendorf, T Integrated life-cycle analysis. Building Research & Information, Vol. 30, No. 5, pp LEED Lima, Celson and Hans, Julien STAN INN Handbook. To be published by STAND-INN: Integration of performance based building standards into business processes using IFC standards to enhance innovation and sustainable development. Project funded by the European Community, Enterprise and Industry Directorate-General, under the Structuring the European Research Area Programme of the 6th FP Morrissey, E., O Donnell, J., Keane, M. and Bazjanac, V Specification and implementation of IFC based performance metrics to support building life cycle assessment of hybrid energy systemes. SimBuild 2004: Building Sustainability and Performance Through Simulation, US 08/04/ /06/2004; 8 p. NBIMS 2007.National BIM Standard in USA. In: htpp:// Nilsson, Lars-Olof, Vares, Sirje and Vesikari, Erkki Service life tools. In: Häkkinen, Tarja, Vares, Sirje, Huovila, Pekka, Vesikari, Erkki, Porkka, Janne, Nilsson, Lars-Olof, Togerö, Åse, Jonsson, Carl, Suber, Katarina, Andersson, Ronny, Larsson, Robert & Nuorkivi, Isto. VTT Research Notes VTT. Espoo (2007), PROMISE Senate Properties BIM requirements. In: htpp:// Senate Properties Business areas. In: Shelbourn, M. A., Bouchlaghem, D.M., Anumba, C.J., Carillo, P.M., Khalfan, M.M.K. and Glass, J Managing knowledge in the context of sustainable construction. ITcon. Vol. 11, pp Schminke, Eva Interview (Eva Schminke as the interviewee and Tarja Häkkinen as the interviewer). Will be published as a part of the results for the Finnish project Sustainable Building State-of-the-art review Shohet, I. M., Puterman, M. & Gilboa, E Deterioration patterns of building cladding components for maintenance management. Construction Management and Economics, Vol. 20, pp Siltanen, P., Vares, S., Ylikerälä, M. and Kazi, A.S.. IFC and PMO for estimating building environmental effects. ICE th International Conference on Concurrent enterprising. 7p. Statsbygg BIM requirements. In: htpp:// Söderqvist, M. and Vesikari, E Life Cycle Management Process. In: Predictive and Optimised Life Cycle Management. Buildings and Infrastructures. Chapter 5. Taylor and Frances. ss Vanier, D.J Why industry needs asset management tools. Journal of computing in civil engineering. Vol 15, no. 1, Jan. 2001, pp Vesikari, E Life cycle management tool for buildings. Manuscript for Durability of Building Materials and Components 2008 Conference. 11 p. 686 Authors Index Program Index