Brenda is an Emeritus Fellow at the ECI following her retirement in September 2008. She is also a Visiting Professor at the University of Exeter. At the ECI, Brenda was the former head of the Lower Carbon Futures team and a co-director of the UK Energy Research Centre Her main research focus is on how to achieve demand reduction in energy across the UK economy, but in particular the built environment.
Brenda's main research focus is on energy efficiency and the way that energy is used in British homes, particularly by low-income households, i.e. fuel poverty. She considers the economic, social and technical aspects of the subject and her work has a strong policy emphasis. She is widely viewed as one of the most experienced in her field and was awarded an MBE in 1998 for her work on energy efficiency and received the Energy Institute's Melchett Medal in the same year.
Brenda's second book, Fixing Fuel Poverty: Challenges and solutions is available in both paperback and hardback. The book examines why the numbers of households in fuel poverty are rising – currently 5m in the UK – despite the government's legal obligation to eradicate fuel poverty by 2016. Many of the lessons from the UK are germaine to other countries beginning to experience worsening fuel poverty, particularly in Eastern and Central Europe. The European Commission now requires action on fuel poverty in all Member States, through the revised Electricity Directive. Brenda has given a series of presentations about the book to various professional and academic audiences in the UK, in Brussels and in Prague.
Brenda continues to supervise two doctoral students and to give occasional lectures to the MSc in Environmental Change and Management. She also contributes to the MSc in Energy Policy at Exeter University and is external examiner for the MSc in Theory and Practice of Sustainable Design, Welsh School of Architecture, Cardiff University.
- Brenda Boardman on making our homes energy efficientThe Life Scientific, BBC Radio 4, 21 September 2021.
- Nearly a third less electricity used to light homes than in 1997 (£) Financial Times, 16 February 2014
- Fuel poverty is getting worse. Can Ed Miliband save the day? The Guardian, 9 October 2013
- Brave new world: The relentless progress of global warming can only be waylaid by redesigning the homes we live in and cutting emissions. Brenda Boardman looks ahead to a greener, cleaner 2050 The Guardian Newspaper, 30 March 2005
Achieving Zero: delivering future-friendly buildings
This report provides a policy framework to ensure that all energy use in all buildings in the whole UK results in zero carbon emissions by 2050. The study views the challenges from a people’s perspective – the roles of the property owner and the occupant – with the implications for energy supply one of the results. The emphasis on energy services, rather than energy purchases, shifts the debate on to demand reduction rather than energy supply and on to lower, not higher, bills. Investing in greater energy efficiency provides users with a better standard of living: a future-friendly property is one that it is warmer, more comfortable, healthier.
Home truths: A low-carbon strategy to reduce uk housing emissions by 80% by 2050
Home Truths reveals that not only is an 80 per cent cut in household emissions achievable, but it can be done in an equitable and fair way that wipes out fuel poverty and enables every UK citizen to live in a warm, comfortable home. The low-carbon house – the individual is warmer, has more hot water and can even have more appliances than now. Carbon emissions are cut, national energy security is increased and fuel poverty has disappeared. Market transformation is the strategic approach recommended, setting a long-term policy framework and recognises that combinations of policies are the most effective.
Special issue of Energy Policy on fuel poverty
In 2012 a special issue of the international journal Energy Policy commemorated 21 years of research and policy related to fuel poverty. The issue is a tribute to the work of Brenda Boardman and hails her as the primary “researcher, strategic thinker and campaigner” on the world of fuel poverty.
- View the special edition online: Fuel poverty comes of age: Commemorating 21 Years of Research and Policy.
- The missed exam: Conversations with Brenda Boardman by Christine Liddell. Energy Policy, 49: 12-18.
- Armstrong, R.C., Wolfram, C., de Jong, K.P., Gross, R., Lewis, N.S., Boardman, B., Raguaskas, A.J., Ehrhardt-Martinez, K., Crabtree, G. and Ramana, M.V. (2016) The frontiers of energy Nature Energy, 1.
- Whitty, L., Boardman, B., Feltham, A., Saunders, J., Tillett, G. and Watson, J. (2016) Understanding fuel poverty. Lehmann Fund final report.
- Boardman, B. (2015) Housing, energy efficiency and fuel poverty. Chapter 19 in, Barton, H., Thompson, S. Burgess, S. and Grant, M. (eds.) Handbook of Planning for Health and Well-Being . pp. 271-282. ISBN: 978-1-13802-330-7.
- Boardman, B. (2015) Low-energy lights will keep the lights on Carbon Management, 5(4): 361-371.
- Boardman, B. (2012) Achieving Zero: Delivering Future-Friendly Buildings ECI, Oxford. ISBN: 9781874370512. Supported by a grant from the Greenpeace Environmental Trust.
- Boardman, B. (2012) Energy, poverty and development. In: Global Energy Assessment: toward a sustainable future Cambridge University Press. Commissioned by GEA and IIASA. ISBN: 9780521182935.
- Boardman, B. (2012) Environmental and energy issues. In: Housing 2020: six views of the future for housing associations. Commissioned by Orbit Group. pp. 73-86.
- Boardman, B. (2012) Fuel Poverty In: Smith, S.J. (ed.) International Encyclopedia of Housing and Home. pp. 221-225.
- Boardman, B. (2012) Fuel poverty synthesis: Lessons learnt, actions needed Energy Policy, 49: 143-148.
- Liddell, C. (2012) The missed exam: conversations with Brenda Boardman Energy Policy, 49: 12-18.
- Boardman, B. (2011) Fuel poverty. Geography Review, 24(3): 14-15.
- Boardman, B. (2011) Measuring your energy use. Geography Review, 24(2): 14-15.
- Boardman, B. (2011) The cost of heating your home. Geography Review, 24(1): 28-29.
- Boardman, B. (2010) Demand reduction must start at home. Demand reduction must start at home, 12(6): 17-18.
- Boardman, B. (2010) Fixing Fuel Poverty: Challenges and Solutions Earthscan. pp. 256. ISBN: 9781844077441.
- Boardman, B. (2010) Liberalisation and fuel poverty. Chapter 9 in, Rutledge, I. and P. Wright (eds.) UK Energy Policy and the End of Market Fundamentalism Oxford University Press, Oxford. pp. 225-280. ISBN: 9780199593002.
- Fawcett, T. and Boardman, B. (2009) Housing market transformation. The Proceedings of the European Council for an Energy Efficient Economy Summer Study 2009. 429-440. ISBN: 9789163344541.
- Hinnells, M. and Boardman, B. (2009) Market Transformation: Innovation Theory and Practice. In, Foxon, T. and Kohler, J. and Oughton, C. (eds.) Innovation for a low carbon economy: economic, institutional and management approaches Edward Elgar Publishing. pp. 203-229. ISBN: 9781847203823.
- Boardman, B. (2008) Full witness statement by Dr Brenda Boardman for the legal case against the UK Government for failing to meet its legal requirements to eradicate fuel poverty under the Warm Homes and Energy Conservation Act 2000.
- Boardman, B. (2008) Index Key for the legal case against the UK Government for failing to meet its legal requirements to eradicate fuel poverty under the Warm Homes and Energy Conservation Act 2000.
- Brand, C. and Boardman, B. (2008) Taming of the few – The unequal distribution of greenhouse gas emissions from personal travel in the UK Energy Policy, 36(1): 224-238.
- Boardman, B. (2007) Examining the carbon agenda via the 40% House scenario Building Research and Information, 35(4): 363-378.
- Boardman, B. (2007) Home truths: a low-carbon strategy to reduce UK housing emissions by 80% by 2050, pdf A research report for The Co-operative Bank and Friends of the Earth.
- Boardman, B. and Palmer, J. (2007) Electricity disclosure: The troubled birth of a new policy Energy Policy, 35(10): 4947-4958.
- Hinnells, M., Boardman, B., Layberry, R., Darby, S. and Killip, G. (2007) The UK Housing Stock 2005 to 2050: Assumptions used in Scenarios and Sensitivity Analysis in UKDCM2 Environmental Change Institute, University of Oxford 48 pp.
- Boardman, B. (2006) Creating a virtuous circle for climate change with consumers, manufacturers and sufficiency. Energy Efficiency in Domestic Appliances and Lighting.
- Boardman, B. (2006) The challenge of existing uk houses. IABSE Henderson Colloquium, Cambridge, 10-12 July 2006.
- Boardman, B., Jardine, C. and Lipp, J. (2006) Green Electricity Code of Practice: A Scoping Study. Environmental Change Institute. Oxford University Centre for the Environment, University of Oxford, UK
- Brand, C., Preston, J. and Boardman, B. (2006) Integrated travel emissions profiles: final research report to the ESRC. Transport Studies Unit and Environmental Change Institute, University of Oxford
- Palmer, J., Boardman, B., Bottrill, C., Darby, S., Hinnells, M., Killip, G., Layberry, R. and Lovell, H. (2006) Reducing the environmental impact of housing. Final Report, Consultancy study in support of the Royal Commission on Environmental Pollutions 26th Report on the Urban Environment.
- Boardman, B. (2005) Brave New World. The Guardian.
- Boardman, B. (2005) Policy packages to achieve demand reduction. Proceedings of the European Council for an Energy Efficient Economy (eceee) 2005 Summer Study - What works & who delivers?, 30 May - 4 June 2005.. 231-236. ISBN: 9163140020.
- Boardman, B. (2005) Renewable Iceland. Geography review (4): 40-41.
- Boardman, B. (2004) Achieving energy efficiency through product policy: the UK experience. Environmental Science & Policy, 7(3): 165-176.
- Boardman, B. (2004) New directions for household energy efficiency: evidence from the UK. Energy Policy, 32(17): 1921-1933.
- Boardman, B. (2004) Starting on the road to sustainability. Building Research & Information, 32 (3): 264-268.
- Boardman, B., Palmer, J. and Lane, K. (2003) 4CE - Consumer choice and carbon consciousness: Electricity disclosure in Europe. Final project report, ECI research report issue 28. Environmental Change Institute (ECI), University of Oxford, Oxford, UK ISBN: 18734370360.
- Jardine, C., Boardman, B., Osman, A., Vowles, J. and Palmer, J. (2003) Methane UK. (30) Environmental Change Institute (ECI), Oxford, UK.
- Boardman, B. and Fawcett, T. (2002) Competition for the Poor: Liberalisation of Electricity Supply and Fuel Poverty: Lessons from Great Britain for Northern Ireland. Environmental Change Institute, University of Oxford.
- Boardman, B., Banks, N., Kirby, H.R., Fawcett, T., Lane, K. and Hurst, A. (2002) Lower Carbon Futures. Environmental Change Institute (ECI), University of Oxford
- Fawcett, T., Hurst, A. and Boardman, B. (2002) Carbon UK. Environmental Change Institute, University of Oxford.
- Boardman, B. and Darby, S. (2000) Effective Advice: energy efficiency and the disadvantaged. Environmental Change Institute, University of Oxford, UK.
- Milne, G. and Boardman, B. (2000) Making cold homes warmer: the effect of energy efficiency improvements in low-income homes. A report to the Energy Action Grants Agency Charitable Trust Energy policy, 28(6): 411-424.
- Boardman, B. (1998) Rural transport policy and equity: A discussion paper prepared for CPRE, the Countryside Commission and the Rural Development Commission, pdf CPRE. 1-39. ISBN: 0946044821.
- Green, J., Darby, S., Maby, C. and Boardman, B. (1998) Advice into action An evaluation of the effectiveness of energy advice to low income households. Keswick (United Kingdom): Eaga Charitable Trust
- Winward, J., Schiellerup, P. and Boardman, B. (1998) Cool labels: The first three years of the European Energy Label, pdf Environmental Change Unit, University of Oxford. ISBN: 1 874370 21 4.
- Boardman B, K Lane, M Hinnells, N Banks, G Milne, A Goodwin and T Fawcett (1997) Transforming the UK Cold Market. Report from the DECADE team, Environmental Change Unit, University of Oxford. 112pp. ISBN 1874370168.
- Boardman B, T Fawcett, H Griffin, M Hinnells, K Lane and J Palmer (1997) 2MtC: two million tonnes of carbon. DECADE 4th year report, Environmental Change Unit, University of Oxford. 106 pp. ISBN 1874370192
- Boardman, B (1997) EESOP’s fable: a review of the second series of annual reports on the Energy Efficiency Standards of Performance. Energy Action 67, NEA, Newcastle, January
- Boardman, B (1997) Cold houses, warm homes and household energy use: a challenge for the twenty-first century. Paper given at the WWF climate change conference, 'The Road to Kyoto'. 11pp
- Boardman, B (1997) Cold labelling - the UK experience of Energy Labels. Proceedings of the European Council for an Energy-Efficient Economy, June 1997. Vol 1, paper 72. 14pp
- Boardman, B (1997) PowerGen - energy in action. Energy Action 69, NEA, Newcastle, August
- Boardman, B (1997) Contributing to Kyoto: lessons from cold appliances. Energy Utilities 8, September 1997, OXERA, Oxford. Pp24-6
- Boardman, B (1997) Managing demand through economic instruments : social equity (including rural areas). Briefing paper, Transport Policy Review, October 1997
- Boardman B (1997) Understanding consumer behaviour: the implications for UK policy. In Energy efficiency in household appliances, (eds) P Bertoldi, A Ricci and B Huenges Wajer, Proceedings of the First International Conference on Energy Efficiency in Household Appliances, 10-12 November. Springer-Verlag Berlin-Heidelberg. Pp113-124
- Milne, G and B Boardman (1997) Making cold homes warmer: the effect of energy efficiency improvements in low-income homes. A report to the Energy Action Grants Agency Charitable Trust. 32pp
- Anable, J, B Boardman and A Root (1997), Travel Emission Profiles. Environmental Change Unit, University of Oxford. 96pp. ISBN 1874370184
- Boardman, B, Hinnells, M, Lane, K, Milne, G and Palmer J (1996) Efficient appliances and SOP money. Report to the Energy Saving Trust. 10pp
- Boardman, B (1996) A great leap forward. Paper for conference on the Home Energy Conservation Act: reporting, planning and implementing across all housing sectors. Held at De Montfort University, Leicester, June
- Boardman, B (1996), Home energy efficiency scheme (HEES), Response the Department of the Environment consultation paper. Environmental Change Unit, University of Oxford
- Root, A, B Boardman and W J Fielding (1996) Rural Travel and Transport Corridors. SMART (Sustainable Mobility and Accessibility in Rural Transport) interim report. Environmental Change Unit, University of Oxford. 74pp. ISBN 1874370125
- Root, A, B Boardman and W J Fielding (1996) The costs of rural travel. Final report of the SMART (Sustainable Mobility and Accessibility in Rural Transport) project. Environmental Change Unit, University of Oxford. 82pp. ISBN 187437015X.
- Boardman B (1995) Freezing out the poor: raising domestic energy prices is not good environmental policy New Economy, September 1995, pp 152-156. Dryden Press
- Boardman B (1995) Policy instruments - a survey. Workshop on energy savings in home entertainment electronics, Copenhagen, 15-16 May
- Boardman, B (1995), as a member of the Energy Working Group, Energy & Environment in the 21st Century. National Academies Policy Advisory Group (NAPAG). 104pp. July
- Boardman B (1995) Lessons from VAT on domestic fuel. The Guardian, October 2
- Boardman B (1995) Energy and the environment, chapter in Environment, Health & Medical Care for the 21st Century, edited by Eiji Yano, Teikyo University. Proceedings of the First Teikyo-Harvard Symposium, Tokyo, pp84-99
- Boardman B (1995) Through the looking glass: energy efficiency projects funded by electricity companies, Energy Action, NEA, Newcastle, November, pp14-15
- Hinnells, M.J., K.B., Lane, E Small, B Boardman and N Middleton (1995) Policy options: energy and emissions savings from intervention. Background report no 10 in A study of efficiency in washing machines, dishwashers and dryers, a report to DG XVII (Energy) of the European Commission. Danish Energy Agency
- Boardman B, D Favis-Mortlock, M Hinnells, K Lane, G Milne, J Palmer, E Small, V Strang and J Wade (1995) DECADE (Domestic Equipment and Carbon Dioxide Emissions) second year report. Environmental Change Unit, University of Oxford. 147pp
- Boardman B (1995) Assessing regulatory impacts. Discussant contribution, Proceedings of Energy and Environment Regulation Workshop. Regulatory Policy Institute, University of Oxford.
- Boardman, B, M J Hinnells and G Milne (1995) Estimation of the energy use in the EU, 1985-2010. Study of standby losses and energy saving potential for televisions and video recorders in Europe. Part A, Novem BV, Sittard NL
- Boardman B, D Favis-Mortlock, M Hinnells, K Lane, G Milne, E Small, V Strang and J Wade (1994) DECADE (Domestic Equipment and Carbon Dioxide Emissions) first year report. Energy and Environment Programme, Environmental Change Unit, University of Oxford. 83pp
- Boardman B (1994) Energy efficiency and UK households. Energy and Environment 4 pp316-334
- Hunt, S and Boardman B (1994) Defining the problem. In: Domestic Energy and Affordable Warmth (ed T A Markus). Watt Committee report 30. ISBN 0 419 20090 8. pp 17-32. London, E & F N Spon
- Boardman B (1994) Strategies for action. In: Domestic Energy and Affordable Warmth (ed T A Markus). Watt Committee report 30. ISBN 0 419 20090 8. pp 81- 96. London, E & F N Spon
- Boardman B (1994) Energy efficiency measures and social inequality, in Housing and the environment: a new agenda (eds M Bhatti, J Booke and M Gibson), Chartered Institute of Housing, Policy and Practice Series. pp 107-127
- Boardman B (1994) DECADE - Domestic Equipment and Carbon Dioxide Emissions, in The SAVE Programme: overview and future. Proceedings of the conference held in Florence, October 26-28. 14pp
- Boardman B (1993), Energy inefficient Europe: the scale of the problem. Paper presented at conference on `Towards an Energy Efficient Europe', Birmingham, 20-21 January. Neighbourhood Energy Action. Newcastle. 6pp
- Boardman B, Energy efficiency incentives and UK households Energy and Environment, 4 (4), 316-334.
- Boardman B (1993) Response to the Department of the Environment’s Climate Change discussion document. Together with the National Right to Fuel Campaign. 8pp
- Boardman B (1993) Comments on OFFER’s consultation document on Energy Efficiency Standards of Performance, March. 9pp
- Boardman, B (1993), Cold facts about fuel poverty. Innovations in social Housing. No 4. March. Pp5-6
- Boardman B (1993) Investment in energy efficiency. Energy and Environment in the South West conference proceedings, Camborne School of Mines. April.
- Boardman B (1993) Uncertainty and the British household. Paper presented to the Demand Side Management and Energy Efficiency conference, Stockholm, September. 12pp
- Boardman B (1993) Prospects for affordable warmth. In Aspects of Unhealthy Housing, R Burridge and D Ormandy (eds), Chapman and Hall. pp382-400
- Boardman B (1993) Energy Efficiency in Buildings. Submission on behalf of the Environmental Change Unit, University of Oxford to the Environment Committee, House of Commons, Fourth Report, Session 1992-93. HC648-III, HMSO
- Boardman B (1993) The opportunities and constraints posed by fuel poverty on policies to reduce the greenhouse effect in Britain Applied Energy, 44, pp185-195
- Boardman B (1993) Implications for low-income households of the imposition of VAT on domestic energy. Environmental Change Unit, University of Oxford
- Boardman, B (1993), Response to the Energy Saving Trust, Residential Scheme. Environmental Change Unit, University of Oxford, December. 10pp
- Boardman, B (1992), Energy efficiency and the utilities. Report to the National Consumer Council. January. 13pp
- Boardman B (1992) Why energy efficiency? Energy Utilities, Oxera, Oxford, February. Pp23-26
- Boardman B (1992) Fuel Poverty. Environmental Health, March, pp 61-5
- Boardman B (1992) Effects of electricity privatisation for consumers. Submission to the House of Commons Energy Select Committee inquiry on behalf of the National Right to Fuel Campaign and Right to Warmth, in HC 113-II, session 1991-92. 13pp
- Hulme, M, P Haves and B Boardman (1992) Impacts of climate change. Innovative Cooling Systems Workshop, Future Buildings Forum, International Energy Agency, May. 13pp
- Boardman, B (1992), Comments from the National Right to Fuel Campaign on the OGGER Energy Efficiency Consultation Document, June, 5pp
- Boardman B (1992) Social aspects of energy efficiency. Energy efficiency: the policy agenda for the 1990s. I Christie & N Ritchie (eds), Policy Studies Institute, London
- Boardman B (1992) Energy efficiency: the role of the local authority. Environmental Health Congress, September 14-17, Bournemouth. 6pp
- Boardman B (1992) Paying for energy efficiency. Paper for National Society for Clean Air Conference, 19-22 October, Bournemouth
- Boardman, B (1992), When is a house not a house? Presentation at the Right to Warmth Seminar, Glasgow on A legal right to warmth?, November, 10pp
- Boardman B (1991) Fuel poverty: from cold homes to affordable warmth. Belhaven Press (now Wiley). Out of print. 267pp. ISBN 1 85293 139 6
- Boardman B (1991) Ten years cold: lessons from a decade of fuel poverty. Neighbourhood Energy Action, Newcastle
- Boardman B (1991) Aspects of energy literacy and public awareness. Conference on Towards a cohesive policy for energy education in the UK, Cranfield Institute of Technology. 4pp
- Boardman, B (1991), Memorandum submitted by the National Right to Fuel Campaign, Energy efficiency, Energy Select Committee, House of Commons, Third Report, Session 1990-91, Volume II, Memoranda of Evidence. 91-II, pp96-98
- Boardman B (1991) Social aspects of energy efficiency. Background paper for Neighbourhood Energy Action and Policy Studies Institute seminar
- Boardman B (1991) Fuel Poverty is different. Policy Studies 12 (4). Policy Studies Institute. pp 30-41 ECU Reprint Series RP-91-1.
- Boardman B and T Houghton (1991) Poverty and power: the efficient use of electricity in low-income households. Bristol Energy Centre. Funded by Joseph Rowntree Foundation. 100pp
- Boardman, B (1991), Additional comments on Ofgas tariff review: E factor and associated standards of performance. Submitted on behalf of the National Right to Fuel Campaign. November. Pp4-6
- Boardman B (1991) Prospects for affordable warmth. Paper presented to Unhealthy Housing conference, Legal Research Institute, Warwick University, December. 6pp
- Boardman B (1990) Fuel poverty and the greenhouse effect. Friends of the Earth, Heatwise Glasgow, National Right to Fuel Campaign, Neighbourhood Energy Action, April, 15pp
- Boardman, B (1990), Home Energy Efficiency Scheme. Response to Energy Efficiency Office consultation paper, on behalf of the National Right to Fuel Campaign, May. 11pp
- Boardman, B (1989) Beating the cold: the role of social services, Social Work Today. 19 January, pp20-21
- Hughes, D and Boardman, B (1989), Cheap Heat, Housing, February, Vol 25.1,pp12-13
- Boardman, B (1989), Powerless poor, Housing, February, Vol 25.1, pp15-17
- Boardman, B (1989), Memorandum on behalf of the National Right to Fuel Campaign and oral evidence, Efficiency of electricity use. Select Committee on the European Communities, House of Lords, Session 1988-89, 8th Report. HL Paper 37, 18 April, pp99-109
- Boardman B (1988) Energy efficiency policy and low income households. In: D Reay and A Wright (eds) Innovation for energy efficiency, Pergamon Press, Oxford
- Boardman B (1988) Little and large: problems and potential for the control of domestic energy consumption. Paper presented at ‘Automating the Home 88’ conference, organised by National Economic Development Organisation and RMDP, London, December
- Boardman, B (1988), Little and large: problems and potential for the control of domestic energy consumption. Paper presented to the Automating the home 88 conference, NEDO & RMDP, December
- Boardman, B (1988), The ‘woollen hat’ solution: fuel poverty – how to break the cold spell. Poverty 71 pp11-12
- Boardman, B (1987), Affordable warmth – can energy costs be related to the ability to pay? Voluntary Housing. April, 8-9
- Boardman B (1987) Defining affordable warmth. Paper presented at Unhealthy Housing conference organised by the Institution of Environmental Health Officers and the Legal Research Unit, University of Warwick, December
- Boardman B (1986), Fuel poverty: the need for a low-income energy efficiency programme. Energy UK, Public Money Journals
- Boardman B (1986) Seasonal mortality and cold homes. Paper presented at Unhealthy Housing conference organised by the Institution of Environmental Health Officers and the Legal Research Unit, University of Warwick, December
- Boardman B (1985) Activity levels in the home. Paper presented at an international conference for building researchers, Budapest, September
- Boardman, B (1985), Energy Efficiency Office, Submission to the House of Commons Select Committee on Energy, on behalf of the National Right to Fuel Campaign. 16pp
- Boardman B (1984) The cost of warmth, national right to fuel campaign, London. ISBN 0 9509429 0 1