The lack of a recognized theoretical disciplinary base for the built environment has been noted on a number of occasions. The field holds the promise of being interdisciplinary, but requires the development of a common epistemological construct. It has been proposed that a unified theory of the built environment may require that the built environment be understood as a complex social–ecological system. It will argued, however, that the challenge is more fundamental; that development of an adequate model would require convergence of the ideas of interdisciplinarity and complexity, with concomitant epistemological as well as ontological considerations. The application of whole-system theory to the built environment is explored with special reference to the identification of boundaries and modularities in different domains and the implications for a taxonomy of the built environment. The development of a theoretical base for the field as a whole would facilitate axiological decision-making in the built environment and also inform both curriculum design and research strategy in the subject area.
boundaries, built environment, complex system, criteria, entities, methodology
 Rabeneck, A., A sketch-plan for construction of built environment theory. Building Research & Information, 36(3), pp. 269–279, 2008. http://dx.doi.org/10.1080/09613210801928115
 Moffatt, S. & Kohler, N., Conceptualizing the built environment as a social–ecological system. Building Research & Information, 36(3), pp. 248–268, 2008. http://dx.doi.org/10.1080/09613210801928131
 Rapoport, A. (ed), The Mutual Interaction of People and their Built Environment: A Cross-cultural Perspective, Aldine, Chicago, IL, pp. 7–35, 1976. http://dx.doi.org/10.1515/9783110819052
 Frank, L. & Engelke, P., Multiple impacts of the built environment on public health: walkable places and the exposure to air pollution. International Regional Science Review, 2, pp. 193–216, 2005. http://dx.doi.org/10.1177/0160017604273853
 Carlson, C., Aytur, S., Gardner, K. & Rogers, S., Complexity in built environment, health, and destination walking: a neighborhood-scale analysis. Journal of Urban Health, 89(2), pp. 270–284, 2012. http://dx.doi.org/10.1007/s11524-011-9652-8
 ISO 12006-2, “Building construction - Organization of information about construction works - Part 2: Framework for classification of information” also known as buildingSMART Data Dictionary or International Framework for Dictionaries (IFD) Library, 2015. More details in, available at: http://www.iso.org/iso/iso_catalogue/catalogue_tc/ catalogue_detail.htm?csnumber=61753
 ISO 12006-3, “Building construction - Organization of information about construction works - Part 3: Framework for object-oriented information” also known as buildingSMART Data Dictionary or International Framework for Dictionaries (IFD) Library, 2007.
 OCCS Development Committee, OCCS Net, The Omniclass Construction Classification System, available at: http://www. occsnet. org/.2002, (accessed 1 December 2002).
 Hall, A.D. & Fagen, R.E., Definition of system. Revised introductory chapter: Systems Engineering, Bell Telephone Laboratories, N.Y. Reprinted in General Systems, 1, pp.18–28, 1956, and also in ed. W. Buckley, Modern Systems Research for the Behavioural Scientist. A Sourcebook, Chicago: Aldine, pp. 81–92, 1968.
 Rapoport, A., Modern systems theory - an outlook for coping with change. General Systems, 15, pp. 15–25, 1970.
 Pattee, H.H. (ed), Hierarchy Theory, New York: Braziller, 1973.
 Morowitz, H.J., The Emergence of Everything, Oxford University Press: Oxford, 2002.
 Batty, M., Cities and Complexity, MIT Press: Cambridge, 2007.
 Johnson, J., Cities: Systems of systems of systems. In Complexity Theories of Cities have Come of Age, eds J. Portugali, H. Meyer, E. Stolk & E. Tan, Berlin: SpringerVerlag, 2012.
 Pulselli, R.M. & Tiezzi, E., City Out of Chaos, Southampton: WIT Press, 2009.
 Glanz, K. & Kegler, M.C., Environments: theory, research and measures of the built environment, 2009, available at: http://citeseerx.ist.psu.edu
 Foster, J., Economic systems. In Philosophy of Complex Systems. Vol. 10, Handbook of the Philosophy of Science, C. Hooker, Elsevier: Amsterdam, Oxford, 2011.
 Medin, D. & Waxman, S.R., Conceptual organization. In A Companion to Cognitive Science, W. Bechtel & G. Graham, Blackwell: Oxford, p. 168, 1999.
 Rosch, E., Mervis, C.B., Gray, W.D., Johnson, D.M. & Boyes-Braem, P., Basic objects in natural categories. Cognitive Psychology, 8(3), pp. 382–439, 1976. http://dx.doi.org/10.1016/0010-0285(76)90013-X
 Hooker, C., Introduction to philosophy of complex systems. In Philosophy of Complex Systems. Vol. 10, Handbook of the Philosophy of Science, C. hooker, Elsevier: Amsterdam, Oxford, p. 867, 2011.
 Rees, W.E., Globalisation and sustainability. Conflict or convergence? Bulletin of Science, Technology and Society, 22(4), pp. 249–268, 2002. http://dx.doi.org/10.1177/0270467602022004001
 Mitchell, S.D., Why integrative pluralism? E:CO Special Double Issue, 6(1–2), pp. 81–91, 2004.
 Allen, P.M., The importance of complexity for the research agenda in the built environment. Architectural Engineering and Design Management, 4(1), p. 5, 2008. http://dx.doi.org/10.3763/aedm.2008.S907
 Godfrey, P., Using systems thinking to learn to deliver sustainable built environments. Civil Engineering and Environmental Systems, 3, p. 219, 2010. http://dx.doi.org/10.1080/10286608.2010.482656
 Müller, B., German Annual of Spatial Research and Policy 2010. Urban Regional Resilience: How Do Cities and Regions Deal with Change? Springer, Berlin: Heidelberg, 2011.
 Read, S., Meaning and material: Phenomenology, complexity, science and ‘adjacent possible’ cities. In Complexity Theories of Cities have Come of Age, J. Portugali, H. Meyer, E. Stolk & E. Tan, Springer-Verlag: Berlin, 2012. http://dx.doi.org/10.1007/978-3-642-24544-2_7
 Williams, L.M., Getting to Know the Built Environment as a Complex System, Policy Paper, Wellesley Institute, Toronto, 2013.
 Fioretti, G. & Visser, B., A cognitive interpretation of organizational complexity. E:CO Special Double Issue, 6(1–2), pp. 11–23, 2004.
 Vischer, J.C., Towards a user-centred theory of the built environment, Building Research & Information, 36(3), pp. 231–240, 2008. http://dx.doi.org/10.1080/09613210801936472
 Vasilachis de Gialdino, I., Ontological and Epistemological Foundations of Qualitative Research [85 paragraphs]. Forum Qualitative Sozialforschung / Forum: Qualitative Social Research, 10(2), Art. 30, 2011, available at: http://nbn-resolving.de/ urn:nbn:de:0114-fqs0902307
 Hübenthal, U., Interdisciplinary thought. Issues in Integrative Studies, 12, pp. 55–75, 1994.
 Klein, J.T., Interdisciplinarity and complexity: An evolving relationship. E:CO Special Double Issue, 6(1–2), pp. 2–10, 2004.
 Jaeger, C., Mangalagiu, D. & Mandel, A., Economics as a global system science. Complexity Economics, 2(1), pp. 1–3, 2013. http://dx.doi.org/10.7564/13-COEC21EDI
 Kellert, S.H., Longino, H.E. & Waters, C.K. (eds), Scientific Pluralism. Vol XIX in Minnesota Studies in the Philosophy of Science, University of Minnesota Press, 2006.
 Mikulecky, D.C., The emergence of complexity: science coming of age or science growing old? Computers & Chemistry, 25(4), pp. 341–348, 2001. http://dx.doi.org/10.1016/S0097-8485(01)00070-5
 Caetano, J.C., Curado, H. & Jacquinet, M., On transdisciplinarity in organizations, innovation, and law. In Transdisciplinarity: Joint Problem-solving Among Science, Technology and Society. Workbook I: Dialogue Sessions and Idea Market, eds R. Häberli, R.W. Scholz, A. Bill & M. Welti, Haffmans Sachbuch Verlag: Zürich, 1, pp. 528–533, 2000.