With the effects of climate changebecoming increasingly important, and buildings accounting for 24% of theworld’s greenhouse gas emissions (IEA/ECBCS, 2010)1 , the architecture and construction sectors havebegun moving towards more sustainable methods of building such as using fewernon-renewable materials and avoiding the disturbance of fragile ecosystems.
Manygovernment policies and incentives have aimed to attract developers in thisdirection however US based non-profit organisation, Architecture 2030challenged the world to make all new buildings carbon-neutral by the year 2030.While this certainly is an ambitious proposal, there is significant debateabout whether zero-carbon construction is feasible and affordable enough to beimplemented at a macro scale. The ChallengeUS based non-profit organisation,Architecture 20302challenged the worldwide architecture industry to adopt several targets seekingto reduce the building sector’s reliance on fossil fuels to zero by 2030(Architecture2030, 2006).
To reach these targets, the organisation recommends “… implementing innovative sustainabledesign strategies, generating on-site renewable power and/or purchasing…renewable energy.” Architecture 2030 has also provided 2030 Palette, adatabase with books, publications and other tools for architects and developersthat are interested in creating low-carbon built environments, improving theaccessibility of information on sustainable architecture and making zero-carbonbuilding more feasible. Defining Zero-CarbonThe definition of zero-carbon isimportant especially for the builders and developer that will be implementingzero-carbon building to assess whether they are reaching the targets set byArchitecture 2030. The UK Green Building Council Task Group, a charity whosemission it is to unite the building industry in becoming more sustainable,states that:”Theconstruction industry stands ready to invest in innovation and skills to meethigher standards, but the lack of detail on policy implementation means thatcurrent efforts are fragmented and disparate, creating inefficiencies…”3This Task Group believes that a lackof clear direction could make any targets or goals like the 2030 goal moredifficult to attain for the industry.
According to the UK Department forCommunities and Local Government4, azero-carbon home is one in which “over a year, the net carbon emissions fromenergy use…would be zero” (UK Government, 2006). This quote was included in adocument outlining the UK’s aim to make all new buildings zero-carbon by 2016 andaims to clarify the meaning of zero carbon to the UK building industry. It alsoexpresses that negating the capitalcarbon of the home is not necessary, allowing for materials that releasehigh amounts of carbon during the manufacturing and construction process to beused in zero-carbon homes (UK Government, 2006).
The independent research conducted by TheInstitute for Sustainable Futures at the University of Technology in Sydney5 attemptedto analyse the current definitions for zero carbon building, like thatreferenced above, and other low impact building types to recommend a moresuitable definition to be used in Australia (Riedy et al., 2011). “We recommend the following standard definitionfor zero carbon buildings: A zero carbon building is one that has no net annualScope 1 and 2 emissions fromoperation of building incorporated services. …Recognising that there is no’one-size-fits-all’ definition, we also propose consistent terminology forvariations on this definition, as outlined in Table ES1” 5 Standard definition Zero Carbon Building Include Occupant Emissions Zero carbon occupied building Include embodied emissions Zero carbon embodied building Include all emission sources in the building life cycle Zero carbon life-cycle building No grid connection Autonomous zero carbon building Achieves less than zero emissions Carbon positive building (or carbon positive occupied building etc) Fig.1. (TableES1) Variations on zero-carbon building definitions, 2011 5The Institute for Sustainable Futures’recommended definition, like that of The UK Department for Communities andLocal Government, specifies that electricity and carbon used to heat and powerthe built-in facilities of a building must also be net zero for it to beconsidered zero carbon (Riedy et al., 2011).
The report declines to includefactors, such as the energy required to power loose appliances that would bebrought into the home upon moving in or the embodied energy of the materials used for the building’s fabric inthe list of services that would need to have zero net carbon in the recommendeddefinition. Instead they propose that the alternative definitions listed in thetable be used consistently for variations on the definition. Architect’s PerspectiveThe architecture industry has alreadyshown that it is possible to design a zero-carbon building. For example,Professor Phil Jones6 from the Welsh School of Architecture designedand built a house that goes beyond the requirements of a zero-carbon andproduces more energy than it consumes:”The Welsh and UK Governments…have set targets for very low ‘nearlyzero’ energy buildings by 2020, and zero carbon new housing can deliver thisand more…. Through this project we have risen to this challenge and used thelatest design and technology to build the UK’s first smart energy positivehouse” 6Professor Jonesbelieves that it is possible to rise to ambitious energy targets using”affordable technologies” and took some design compromises to cut costs, namely,building the south facing roof completely out of solar panels instead ofattaching the panels to a conventional roof. In his opinion, this kind ofinnovative approach to building should be employed to meet low energy targets While Professor Jones’ design relieson energy saving technology to become energy-positive, Clare Murray7,Head of Sustainability at Levitt Bernstein architecture firm, argues thatlow-carbon technologies within homes do not perform as well in reality as theyare predicted to thus making it difficult for them to reach their zero-carbongoals:”Predicted system efficiencies often far exceed those installed.
It isthese gaps between design and reality which render the CO2 reductionson paper meaningless and prevent the best outcome for residents and maintenanceteams.” 7Universityof Florida’s Professor Charles Kibert8attributes these inefficiencies to occupant behaviour since “there is no vestedinterest… to limit their consumption”. Kibert also emphasises that, withoutadequate involvement from the owners or occupants of zero-carbon buildings, itwill be difficult to reach zero-carbon goals on a larger scale. On his blog,Elrond Burrell9, RegisteredArchitect and Certified PassivhausDesigner based in the UK, raises the issue of suitable locations for designingzero carbon homes since a zero-carbon home can generate renewable energyon-site to account for its electricity uses and many sites hold constraintsthat make this difficult. Burrell cites urban areas as particularly unsuitabledue to high building density, as limited roof space and nearby buildingscasting shadows onto the site may hamper its efforts to harness solar and windpower. This could threaten the feasibility of zero-carbon building across theUK since there are a range of densely populated and sparsely populatedsettlements located here.
While 2030 Architecture recommends the purchase ofrenewable energies when generation is not possible, this remains a significantissue as it asks where the generation of the increased demand for renewableenergy would take place. Finally, astudy conducted by Plymouth University, Edinburgh University and Hong KongUniversity in China surveyed 34 professionals in the architecture industry Government opinions+ In his 2015statement, former chancellor of the Exchequer George Osborne declared that theUK government would discontinue its zero-carbon and Allowable Solutions targetscarbon off-setting scheme to make it easier for planning 1 IEA/ECBCS (2010) http://www.iea-shc.org/data/sites/1/publications/T40A52Flyer3a.
pdf, Date Accessed: 30thNovember 20172 Architecture2030, http://architecture2030.org/2030_challenges/2030-challenge/ , Date Accessed: 23 November20173 UKGreen Building Council (2014)https://www.ukgbc.org/sites/default/files/Building%20Zero%20Carbon%20-%20case%20for%20action.
%20Exec%20Summary%20Final%20%281%29.pdf, Date Accessed: 15 December 20174 UK Government 2006, ‘Building a Greener Future: Towards ZeroCarbon Development: Consultation’ Department of Communities and Local Government,(2006), pp.3, Communities and Local Government Publications (West Yorkshire)http://webarchive.
gov.uk/documents/planningandbuilding/pdf/153125.pdf ,Date Accessed: 29thNovember 20175Riedy, C., Lederwasch, A., and Ison, N.
, (2011) ‘Defining zero emissionbuildings – Review and recommendations: Final Report’. Prepared forSustainability Victoria by the Institute for Sustainable Futures, University ofTechnology, Sydneyhttp://www.asbec.asn.au/files/ASBEC_Zero_Carbon_Definitions_Final_Report_Release_Version_15112011_0.pdf , Date Accessed: 29th November 2017 6Cardiff University (2015), https://www.cardiff.ac.uk/news/view/122063-smart-carbon-positive-energy-house, Date Accessed: 2nd December 20177 Clare Murray (2016), https://www.architectsjournal.co.uk/opinion/chasing-zero-carbon-targets-in-dense-residevelopments-is-like-chasing-rainbows/10010488.article , Date Accessed: 29th November 20178Nadiv Malin (2010), https://www.buildinggreen.com/feature/problem-net-zero-buildings-and-case-net-zero-neighborhoods ,Date Accessed: 2ndDecember 9Elrond Burrell (2014),https://elrondburrell.com/blog/zero-carbon-buildings-wrong-target/,Date Accessed: 2nd December 2017