The research outlined in this paper is part of a collaborative fund to propose an innovative classification framework for restoration of historical/cultural heritage assets. Most of the previous research/applications in applying BIM to Heritage have focused on the physical or geometric reporting of assets. This typically involves laser scanning for creating as-built models and recording asset components, for operations and maintenance. However to efficiently identify/record general asset component requirements, standardised classification systems must be used which categorise different components, their characteristics, attributes, and maintenance requirements. Furthermore as will be demonstrated, current database, knowledge and classification systems available for new builds might not be suitable to categorise components in historical buildings, which differ according to historical eras and architectural periods, hence might render their restoration process inefficient. There is currently no research dedicated towards investigating appropriate classification systems to be used for heritage buildings. This paper provides a comparative study between current international classification systems within the construction industry, and investigates their suitability for heritage buildings. This includes CI/SFB, CAW, SFG20, Omniclass, Uniclass versions etc. Properties of suitability will also be investigated e.g. object types, hierarchy of tables/schedules, depth levels and appropriateness for different architectural styles and parametric geometries (e.g. origin, material, allowed stresses, proportions etc.). This study provides evidence for the lack of appropriate classification systems for Heritage and provides recommendations for a taxonomical representation for suitable classification systems of Heritage assets from different historical and architectural periods. This includes information descriptors of hierarchical classes, historical, social and technological context, allowing usage of standardised Heritage BIM data for documentation, operations, maintenance and restoration management, and also allowing searching for similarities/differences between different buildings in the global heritage domain, replacement components and comparing artefacts, which might impact historical significance.
building information modelling, CAW, CI/SFB, classifications systems, heritage buildings, omniclass, SFG20, typology, uniclass
 Bhawan, N., Conservation of heritage buildings - a guide, Directorate General Central Public Works Department : New Delhi, pp. 1–2, 2013.
 Designing Buildings Wiki. BIM classification, available at: https://www.designingbuildings. co.uk/wiki/BIM_classification. (accessed 5 March 2017).
 Firley, E. & Stahl, C., The urban housing handbook. Chichester/Hoboken: Wiley, pp. 1–9, 2009.
 Caniggia, G. & Maffei, G., Architectural composition and building typology: interpreting basic building. Aliniea Editrice, Florence, 2001.
 Scheer, B.C., The evolution of urban form: typology for planners and architects. American Planning Association, 2010.
 Gelder, J., Classification, available at: http://www.cpic.org.uk/wp-content/uploads/2013/06/classification_v1.2.pdf. (Accessed on 6 March 2017).
 Ray-Jones A., Classification by CI/SfB. Journal of Building Research and Practice, 2(6), pp. 314–316, 1974.
 Designing Buildings Wiki, Common arrangement of work sections, available at: https://www.designingbuildings.co.uk/wiki/Common_Arrangement_of_Work_Sections. (Accessed 6 March, 2017).
 Finch, R., Co-ordinating common arrangement, uniclass, NBS and rules of measurement, available at: https://www.thenbs.com/knowledge/co-ordinating-common-arrangementuniclass-nbs-and-rules-of-measurement. (Accessed 6 March 2017).
 Ralph, M., The standard for maintenance, available at: http://hfc.org.uk/wp-content/uploads/2016-06-MikeRalph.pdf. (Accessed 6 March, 2017).
 FMWorld, Maintaining standards, available at: http://www.fm-world.co.uk/features/feature-articles/maintaining-standards/. (Accessed 6 March 2017).
 4BT, OMNICLASS vs. UNICLASS / UNICLASS2 – BIM Ontology, available at: https://jobordercontracting.org/2013/06/06/omniclass-vs-uniclass-uniclass2-bim-ontology/. (Accessed 1 March, 2017).
 Gelder, J., Omniclass: a critique, available at: https://www.thenbs.com/knowledge/omniclass-a-critique. (accessed 2 March 2017).
 NBS, Uniclass 2015 - an update, available at: https://www.thenbs.com/knowledge/uniclass-2015-an-update. (accessed 12 March 2017).
 CPIx, Uniclass2, available at: http://www.cpic.org.uk/uniclass/. (accessed 12 March 2017).
 BIM Taskgroup, Uniclass 2: Demystified, available at: http://www.bimtaskgroup.org/wp-content/uploads/2013/06/BIM-Task-Group-Newsletter-21st-Edition.pdf. (accessed 12 March 2017).
 RICS, RICS NRM: new rules of measurement, available at: https://www.rics.org/uk/knowledge/professional-guidance/guidance-notes/new-rules-of-measurement-orderof- cost-estimating-and-elemental-cost-planning/. (accessed 12 March 2017).
 Earl, S. The RICS’ new rules of measurement, available at: http://www.building.co.uk/the-rics-new-rules-of-measurement/5033890.article. (accessed 12 March 2017).
 Bryan, P. BIM for heritage: developing an historic building information model. Presentation, Historic England, UK, 2017.
 Andreetto, M., Brusco, N. & Cortelazzo, G.M., Automatic 3D modeling of textured cultural heritage objects. IEEE Transactions on Image Processing, 13(3), pp. 354–369, 2004. https://doi.org/10.1109/tip.2003.821351
 Crawford, R.H. & Stephan, A. (eds.), Living and learning: research for a better built environment. 49th International Conference of the Architectural Science Association 2015, The Architectural Science Association and The University of Melbourne, pp. 287–297, 2015.
 Jorgensen, K. A., Classification of building object types- misconceptions, challenges and opportunities. Proceedings of CIB W78-W102 International Conference. Sophia Antipolis, France, 26–28 October 2011.
 Afsari, K. & Eastman, C.M., A comparison of construction classification systems used for classifying building product models. In 52nd ASC Annual International Conference Proceedings, 2016.
 Ekholm, A., A conceptual framework for classification of construction works. ITcon (Electronic Journal of Information Technology in Construction), 1, pp. 1–25, 1996.
 Ekholm, A., & Häggström, L., Building classification for BIM – Reconsidering the framework. Proceedings of the CIB W078-W102: 2011 Joint International Conference. Sophia Antipolis, France, 26–28 October, 2011. Retrieved from http://2011-cibw078-w102.cstb.fr/papers/Paper-20.pdf