Vertical Extensions: Stakeholder Perspectives on Development Decisions and Construction Strategies
Publication: Journal of Architectural Engineering
Volume 29, Issue 2
Abstract
A vertical extension (VE) involves the construction of additional floor space on top of an existing base building. With growing urban populations and an urgency to reduce building-related carbon emissions, VEs might have the potential to be a sustainable and innovative solution to overcome the shortage of urban spaces. However, despite the growing number of projects and the emerging academic literature, limited research has documented the decisions that inform the development of VE projects or the lessons learned from stakeholders that were involved in their creation. This paper presents the early decision-making processes that are undertaken to select a VE as an appropriate development type to construct in practice, and the common challenges and solutions during its realization, through semistructured interviews with a broad range of stakeholders, including developers, contractors, architects, and structural engineers that have been involved in recently completed VE projects. The results identify that the main driver of VEs is economic profit, followed by sustainability goals and the desire to stay on the same site. The challenges are related to the complex design and coordination of VE projects, and onsite construction challenges. In addition, this paper identifies the diverse structural support and reinforcement strategies that are used in VEs and contributes to the knowledge by capturing the different aesthetic and construction approaches that are used in practice.
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Acknowledgments
This work was supported by an Australia Awards Scholarship.
References
Adlerstein, M. 2016. Assessing the carbon-saving value of retrofitting versus demolition and new construction at the United Nations headquarters. New York: Vidaris and Sycka Hennessy Group.
Amer, M., and S. Attia. 2019. “Identification of sustainable criteria for decision-making on roof stacking construction method.” Sustainable Cities Soc. 47: 101456. https://doi.org/10.1016/j.scs.2019.101456.
Amer, M., A. Mustafa, and S. Attia. 2019. “Conceptual framework for off-site roof stacking construction.” J. Build. Eng. 26: 100873. https://doi.org/10.1016/j.jobe.2019.100873.
Amer, M., A. Mustafa, J. Teller, S. Attia, and S. Reiter. 2017. “A methodology to determine the potential of urban densification through roof stacking.” Sustainable Cities Soc. 35: 677–691. https://doi.org/10.1016/j.scs.2017.09.021.
Aparicio-Gonzalez, E., S. Domingo-Irigoyen, and A. Sánchez-Ostiz. 2020. “Rooftop extension as a solution to reach nZEB in building renovation. Application through typology classification at a neighborhood level.” Sustainable Cities Soc. 57: 102109. https://doi.org/10.1016/j.scs.2020.102109.
Artés, J., G. Wadel, and N. Martí. 2017. “Vertical extension and improving of existing buildings.” Open Constr. Build. Technol. J. 11 (Suppl-1, M4): 83–94. https://doi.org/10.2174/1874836801711010083.
Bergsten, S. 2005. “Industrialised building systems: Vertical extension of existing buildings by use of light gauge steel framing systems and 4D CAD tools.” Licentiate thesis, Dept. of Civil and Environmental Engineering, Lulea University of Technology.
Braun, V., and V. Clarke. 2006. “Using thematic analysis in psychology.” Qual. Res. Psychol. 3 (2): 77–101. https://doi.org/10.1191/1478088706qp063oa.
Braun, V., and V. Clarke. 2021. “One size fits all? What counts as quality practice in (reflexive) thematic analysis?” Qual. Res. Psychol. 18 (3): 328–352. https://doi.org/10.1080/14780887.2020.1769238.
Burchell, R. W., N. A. Shad, D. Listokin, and H. Phillips. 1998. The costs of sprawl-revisited. Washington, DC: Transportation Research Board.
Cappai, F., D. Forgues, and M. Glaus. 2019. “A methodological approach for evaluating brownfield redevelopment projects.” Urban Sci. 3: 45. https://doi.org/10.3390/urbansci3020045.
Chastas, P., T. Theodosiou, and D. Bikas. 2016. “Embodied energy in residential buildings-towards the nearly zero energy building: A literature review.” Build. Environ. 105: 267–282. https://doi.org/10.1016/j.buildenv.2016.05.040.
Criado-Perez, C., C. G. Collins, C. J. Jackson, P. Oldfield, B. Pollard, and K. Sanders. 2020. “Beyond an ‘informed opinion’: Evidence-based practice in the built environment.” Archit. Eng. Des. Manage. 16 (1): 23–40. https://doi.org/10.1080/17452007.2019.1617670.
Dind, A., S. Lufkin, and E. Rey. 2018. “A modular timber construction system for the sustainable vertical extension of office buildings.” Designs 2 (3): 30. https://doi.org/10.3390/designs2030030.
Dow, A. 2017. “Can you extend skyascraper? Yes you can.” The Age. Accessed March 2, 2020. https://www.theage.com.au/national/victoria/can-you-extend-that-skyscraper-yes-you-can-20170227-gumbuv.html.
Dulić, O., and M. Krklješ. 2014. “Brownfield redevelopment as a strategy for preventing urban sprawl.” In Presented at Internacionalni Nauco-Strucni Skup GNP 2014 Gradevinarstvo - Nauka i Praksa. Montenegro, Zabljak: Univerzitet Crne Gore.
Eliason, M. 2014. “Aufstockung: Innovative density.” The Urbanist. Accessed March 3, 2020. https://www.theurbanist.org/2014/07/24/aufstockung-innovative-density/#.
Fatone, S., E. Conticelli, and S. Tondelli. 2012. “Environmental sustainability and urban densification.” In Sustainable city VII: Urban regeneration and sustainability, edited by M. Pacetti, G. Passerini, C. A. Brebbia, and G. Latini. Billerica, MA: WIT Press.
Floerke, P., S. WeiB, L. Stein, and M. Wagner. 2014. Catalogue of typologies - Rooftop extensions. [In German.] Dusseldorf, Germany: Technische Universitat Dormund.
Frey, P., L. Dunn, and R. Cochran. 2011. The greenest building: Quantifying the environmental value of building reuse. Seattle: National Trust for Historic Preservation.
Gillham, B. 2000. The research interview. London: Bloomsbury Publishing.
Given, L. M. 2008. The SAGE encyclopedia of qualitative research. Thousand Oaks: Sage.
González-Redondo, E. 2022. “Adding new floors to old timber-framed buildings: An assessment of demolished and preserved courtyard houses in the historic centre of Madrid.” Front. Archit. Res. 11 (2): 255–277. https://doi.org/10.1016/j.foar.2021.10.009.
Hermens, M., M. Visscher, and J. Kraus. 2014. “Ultra light weight solutions for sustainable urban densification.” In Proc., CTBUH 2014 Shanghai Conf., 542–549. Shanghai, China: Council of Tall Building and Urban Habitat.
Hernandez-Palacio, F. 2014. “On the feasibility and effectiveness of urban densification in Norway.” Nordic J. Archit. Res. 2: 83–112.
Hevesi, D. 1999. “Adding new floors atop old buildings.” The New York Times. Accessed March 3, 2020, https://www.nytimes.com/1999/10/24/realestate/adding-new-floors-atop-old-buildings.html.
Horsley, C. B. 2008. “Raising the roof in New York City.” The New York Sun. Accessed May 22, 2020. https://www.nysun.com/real-estate/raising-the-roof-in-new-york-city/82028/.
Hurst, W. 2019. “Introducing RetroFirst: A new AJ campaign championing reuse in the built environment.” Architects’ Journal. Accessed January 16, 2022. https://www.architectsjournal.co.uk/news/introducing-retrofirst-a-new-aj-campaign-championing-reuse-in-the-built-environment.
IEA, and UNEP. 2019. 2019 global status report for buildings and construction. Madrid: Global Alliance for Buildings and Construction.
Inertia. 2017. “Adding floors to existing buildings is on the rise.” Accessed March 3, 2020. https://inertiaeng.com.au/2017/11/adding-floors-existing-buildings-rise/.
Jellen, A. C., and A. M. Memari. 2014. “Residential vertical expansion of existing commercial buildings using modular construction methods.” In Presented at 2nd Residential Building Design & Construction Conf. University Park, PA: Pennsylvania Housing Research Center.
Jellen, A. C., and A. M. Memari. 2018. “Residential vertical expansions using modular construction.” J. Archit. Eng. 24 (3): 04018019. https://doi.org/10.1061/(ASCE)AE.1943-5568.0000322.
King, N., and J. Brooks. 2018. “Thematic analysis in organisational research.” In The SAGE handbook of qualitative business and management research methods: Methods and challenges, edited by C. Cassell, A. L. Cunliffe, and G. Grandy. London: Sage.
Kumari, L. M. T., U. Kulatunga, N. Madusanka, and N. Jayasena. 2020. “Embodied carbon reduction strategies for buildings.” In Proc., Int. Conf. on Sustainable Built Environment, edited by R. Dissanayake, and P. Mendis, 295–308. Singapore: Springer.
Kussin, Z. 2016. “Crafty NYC developers are putting buildings on top of buildings.” New York Post. Accessed March 9, 2020. https://nypost.com/2016/01/28/crafty-nyc-developers-are-putting-buildings-on-top-of-buildings/.
Lešnik, M., S. Kravanja, M. Premrov, and V. Žegarac Leskovar. 2020. “Optimal design of timber-glass upgrade modules for vertical building extension from the viewpoints of energy efficiency and visual comfort.” Appl. Energy 270: 115173. https://doi.org/10.1016/j.apenergy.2020.115173.
Logan, K. 2019. “Continuing education: Vertical school expansions.” Architectural Record. Accessed March 31, 2020. https://www.architecturalrecord.com/articles/13826-continuing-education-vertical-school-expansions.
Marique, A.-F., and B. Rossi. 2018. “Cradle-to-grave life-cycle assessment within the built environment: Comparison between the refurbishment and the complete reconstruction of an office building in Belgium.” J. Environ. Manage. 224: 396–405. https://doi.org/10.1016/j.jenvman.2018.02.055.
Maxwell, J. A. 2010. “Using numbers in qualitative research.” Qual. Inq. 16 (6): 475–482. https://doi.org/10.1177/1077800410364740.
Mishra, A., F. Humpenöder, G. Churkina, C. P. O. Reyer, F. Beier, B. L. Bodirsky, H. J. Schellnhuber, H. Lotze-Campen, and A. Popp. 2022. “Land use change and carbon emissions of a transformation to timber cities.” Nat. Commun. 13 (1): 4889. https://doi.org/10.1038/s41467-022-32244-w.
Morris, M. 2021. “Upward extensions: Adding 2 storeys to blocks of flats without planning permission.” Accessed October 26, 2021. https://urbanistarchitecture.co.uk/extending-block-flats-upwards/.
Mouratidis, K. 2019. “Compact city, urban sprawl, and subjective well-being.” Cities 92: 261–272. https://doi.org/10.1016/j.cities.2019.04.013.
Ness, D. 2020. “Growth in floor area: The blind spot in cutting carbon.” Emerald Open Res. 2: 2. https://doi.org/10.35241/emeraldopenres.13420.3.
Neuman, M. 2005. “The compact city fallacy.” J. Plann. Educ. Res. 25: 11–26. https://doi.org/10.1177/0739456X04270466.
Newman, P., and J. Kenworthy. 2015. The end of automobile dependence: How cities are moving beyond car-based planning. Washington, DC: Island Press.
Norell, M., L. Stehn, and D. Engström. 2020. “Architectural design of vertical extensions of buildings: A risk perspective on complexity.” In Proc., 36th Annual ARCOM Conf., 625–634. Belfast, UK: Association of Researchers in Construction Management.
Nowell, L., J. Norris, D. White, and N. Moules. 2017. “Thematic analysis, striving to meet the trustworthiness criteria.” Int. J. Qual. Methods 16: 1–13. https://doi.org/10.1177/1609406917733847.
Oldfield, P. 2019. The sustainable tall building: A design primer. New York: Routledge.
Opoku, A., V. Ahmed, and J. Akotia. 2016. “Choosing an appropriate research methodology and method.” In Research methodology in the built environment, edited by V. Ahmed, A. Opoku, and Z. Aziz. New York: Routledge.
Orr, J., M. P. Drewniok, I. Walker, T. Ibell, A. Copping, and S. Emmitt. 2019. “Minimising energy in construction: Practitioners’ views on material efficiency.” Resour. Conserv. Recycl. 140: 125–136. https://doi.org/10.1016/j.resconrec.2018.09.015.
Østergård, T., R. L. Jensen, and S. E. Maagaard. 2016. “Building simulations supporting decision making in early design – A review.” Renewable Sustainable Energy Rev. 61: 187–201. https://doi.org/10.1016/j.rser.2016.03.045.
Pomponi, F., and A. Moncaster. 2016. “Embodied carbon mitigation and reduction in the built environment - What does the evidence say?” J. Environ. Manage. 181: 687–700. https://doi.org/10.1016/j.jenvman.2016.08.036.
Resch, E., R. A. Bohne, T. Kvamsdal, and J. Lohne. 2016. “Impact of urban density and building height on energy use in cities.” Energy Procedia 96: 800–814. https://doi.org/10.1016/j.egypro.2016.09.142.
Robati, M., and P. Oldfield. 2022. “The embodied carbon of mass timber and concrete buildings in Australia: An uncertainty analysis.” Build. Environ. 214: 108944. https://doi.org/10.1016/j.buildenv.2022.108944.
Robati, M., P. Oldfield, A. A. Nezhad, D. G. Carmichael, and A. Kuru. 2021. “Carbon value engineering: A framework for integrating embodied carbon and cost reduction strategies in building design.” Build. Environ. 192: 107620. https://doi.org/10.1016/j.buildenv.2021.107620.
Schmidt, M., R. H. Crawford, and G. Warren-Myers. 2020. “Quantifying Australia’s life cycle greenhouse gas emissions for new homes.” Energy Build. 224: 110287. https://doi.org/10.1016/j.enbuild.2020.110287.
Shirazi, A., and B. Ashuri. 2020. “Embodied life cycle assessment (LCA) comparison of residential building retrofit measures in Atlanta.” Build. Environ. 171: 106644. https://doi.org/10.1016/j.buildenv.2020.106644.
Soikkeli, A. 2016. “Additional floors in old apartment blocks.” Energy Procedia 96: 815–823. https://doi.org/10.1016/j.egypro.2016.09.143.
Stevenson, M., et al. 2016. “Land use, transport, and population health: Estimating the health benefits of compact cities.” Lancet 388 (10062): 2925–2935. https://doi.org/10.1016/S0140-6736(16)30067-8.
Sundling, R. 2019. “A development process for extending buildings vertically – Based on a case study of four extended buildings.” Constr. Innovation 19 (3): 367–385. https://doi.org/10.1108/CI-05-2018-0040.
Thornton, C. H., U. Hungspruke, and R. P. DeScenza. 1991. “Vertical expansion of vintage buildings.” Mod. Steel Constr. 31 (6): 35–37.
UNEP (United Nations Environment Programme). 2021. 2021 global status report for buildings and construction: Towards a zero-emission, efficient and resilient buildings and construction sector. Nairobi: UNEP.
UN (United Nations). 2017. New urban agenda. New York: UN.
UN (United Nations). 2019. World urbanization prospects: The 2018 revision. New York: Dept. of Economic and Social Affairs.
Wijnants, L., K. Allacker, and F. De Troyer. 2019. “Life-cycle assessment of timber frame constructions - The case of rooftop extensions.” J. Cleaner Prod. 216: 333–345. https://doi.org/10.1016/j.jclepro.2018.12.278.
WorldGBC (World Green Building Council). 2019. Bringing embodied carbon upfront. London: WorldGBC.
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Published In
Journal of Architectural Engineering
Volume 29 • Issue 2 • June 2023
Copyright
© 2023 American Society of Civil Engineers.
History
Received: Apr 7, 2022
Accepted: Jan 10, 2023
Published online: Apr 4, 2023
Published in print: Jun 1, 2023
Discussion open until: Sep 4, 2023
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