Greenhouse gas emissions from construction and buildings
Anthropogenic emissions of greenhouse gases (GHG) are a major cause of global warming and climate change. Measures are now being taken on an international scale to reduce these emissions. However, progress is slow.
Next to industry and transport, the building sector, as a major energy user and producer of associated GHG emissions, merits careful attention. Worldwide, 30-40% of energy is used in buildings. Establishing global standards for sustainable buildings, including energy performance, is difficult because conditions for buildings vary greatly between countries. Important initiatives are, however, being taken in this direction, especially in the European region. Next to regulatory control, the application of tools based on voluntary approaches has an important role to play. Certifiable rating systems for sustainability and energy performance in buildings have proven to be effective in reducing energy consumption and associated GHG emissions.
Climate change and GHG
The quantities of GHG in the atmosphere are increasing as a result of human activity. A major anthropogenic source of GHG is the burning of fossil fuels. This emits carbon dioxide (CO 2 ), which accounts for around 75% of global GHG emissions. Deforestation is also a major source of CO 2 emissions. Other GHG-generating activities include landfill waste, rice cultivation, cattle and fertilisation of agricultural soil, and the production and use of fluorinated industrial GHG. 1, 2, 3, 4
The current level of GHG in the atmosphere is equivalent to around 430 parts per million (ppm) CO 2 equivalents, compared with only 280 ppm before the Industrial Revolution. Concentrations of CO 2 alone have risen from 280 ppm to around 380 ppm. These concentrations have caused the world to warm by more than half a degree Celsius and, because of the inertia in the climate system 3 & 4 , will lead to at least a further half degree warming over the next few decades.
Mitigating the associated climate change and achieving stabilisation of GHG atmospheric concentrations – the objective of the United Nations Framework Convention on Climate Change (UNFCCC) – will require considerable reductions of GHG, including energy-related CO 2 emissions.
The Kyoto Protocol – targets and commitments
The Kyoto Protocol, as an international agreement which builds on the UNFCCC, sets legally binding targets for industrialised countries to reduce their GHG emissions relative to a base year by 2008-2012, calculated as an average of these years. Overall, the Parties to Annex I of the Framework Convention undertake to reduce their GHG emissions by at least 5% below 1990 levels during the period 2008 to 2012. Annex B of the Protocol contains the quantified commitments given by the Parties. Parties who so wish may make 1995 a reference year for emissions of hydrofluorocarbons, perfluorcarbons and sulphur hexafluoride.
The Kyoto Protocol offers flexibility in how countries may meet their targets. For example, they may partially compensate for their emissions by increasing “sinks” – forests, which remove CO 2 from the atmosphere. Countries may also pay for foreign projects that result in GHG cuts, through Joint Implementation (JI) and the Clean Development Mechanism (CDM) referred to as Flexible Mechanisms. A numerically small group – the European Union, USA, Canada, Russia, Japan, China and India – accounts for about 75% of world GHG emissions 4 .
Under the Kyoto Protocol, the EU has committed itself to reducing its GHG emissions by 8% compared to the base year (1990) during the first commitment period 2008-2012. If the further Process Emissions and Global Climate Change Figure 1. Variations in earth’s temperature large rise in global temperatures projected over the coming decades is to be prevented, or at least limited, far-reaching action to curb GHG emissions will be needed after 2012 – the year by which the Kyoto Protocol targets are to be met. The EU is responsible for around 14% of global GHG emissions today.
To be effective this action will have to involve all major emitting nations. This includes the USA (responsible for around 25% of global emissions), which has opted out of the Kyoto Protocol, as well as China (14%), India (6%) and other large developing countries which do not have emission reduction targets under the Protocol. 2 & 5
Greenhouse gases in the Kyoto Protocol
The main greenhouse gas is water vapour which occurs as clouds. These reflect some of the sun’s heat back into space but also trap some of it in the atmosphere. The latter phenomenon creates the natural greenhouse effect that keeps the Earth at a comfortable temperature to support life. The Kyoto Protocol focuses on controlling six gases released by human activities that are enhancing the greenhouse effect and consequently making the world warmer. They are:
- Carbon dioxide (CO 2 ) – the most important greenhouse gas released by human activities in terms of quantity; it is emitted by combustion of fossil fuels, wood or anything else containing carbon, but is also absorbed by plants and trees
- Methane (CH 4 ) – releases come from a range of natural sources and human activities; the latter include fossil fuel production, livestock husbandry, rice cultivation and waste
- Nitrous oxide (N 2 O) – emission sources are fertilisers, fossil fuel combustion and industrial chemical production using nitrogen
- Three types of gases developed specifically for industrial applications – hydrofluorocarbons (HFCs), perfluorocarbons (PFCs) and sulphur hexafluoride (SF6)
Certain other industrial gases, such as chlorofluorocarbons and hydrochlorofluorocarbons, contribute to both global warming and the depletion of the ozone layer. They are not covered by the Kyoto Protocol as they are being phased out under the Montreal Protocol on protecting the ozone layer. Annual emissions of CO 2 , CH 4 , N 2 O, HFC, PFC and SF6 in the UNFCCC reporting format are converted to their global warming potential GWP (100 year time horizon) for addition and comparison with the Kyoto Protocol targets: 1 t CH 4 = 21 t CO 2 -equivalent, 1 t N 2 O = 310 t CO 2 -equivalent, 1 t SF 6 = 23 900 t CO 2 -equivalent. HFCs and PFCs have a wide range of GWPs depending on the gas and emissions are already reported in tonnes CO 2 -equivalent. 1 & 2
Implementation of GHG reduction programmes on a worldwide scale
The Kyoto Protocol suggests various means of attaining its objectives:
- Increasing or introducing national policies to reduce emissions (greater energy efficiency, promotion of sustainable forms of agriculture, development of renewable energy sources, etc.)
- Co-operation with the other Contracting Parties (exchanges of information, co-ordination of national policies in a bid to tackle work effectively through co-operation mechanisms, namely emission permits, joint implementation and a clean development mechanism)
No later than one year prior to the start of the first commitment period, each Party must have set up a national system for the estimation of anthropogenic GHG emissions by sources, and removals by sinks, of all GHG not controlled by the Montreal Protocol.
At their Gleneagles Summit in July 2005, G8 leaders addressed the challenges of climate change and securing clean energy and sustainable development. The G8 leaders asked the International Energy Agency (IEA) to be a partner in this dialogue and to play a major role in delivering the plan of action. The IEA acts as energy policy adviser for its 26 member countries. For this purpose it will focus on six broad areas which also include the building sector:
- Alternative energy scenarios and strategies
- Energy efficiency in buildings, appliances, transport and industry
- Cleaner fossil fuels
- Carbon capture and storage
- Renewable energy
- Enhanced international co-operation
From a worldwide perspective, awareness has been raised that urgent action is required to combat global warming and climate change. A vast diversity of programmes is now being implemented based on tools which include regulatory instruments, voluntary instruments, combinations of these with tax incentives – and subsidies and certification procedures. Within the EU, action has been guided through the European Climate Change Programme (ECCP) 6 . The ECCP covers a wide range of sectors of the economy, defining policy relevant to the household, industrial, commercial and transport sectors.
Measures taken within the framework of the EU Climate Change Programme
- The Greenhouse Gas Emission Allowance Trading Scheme 7 to limit the total carbon dioxide emissions from almost 12000 installations across the EU’s 25 Member States (EU-25)
- The Linking Directive 8 which amends the Emissions Trading Directive to enable Member States to allow operators to use credits obtained through Kyoto mechanisms (certified emission reductions and emission reduction units) to comply with their obligations under the EU ETS
- The Intelligent Energy for Europe 9 programme that promotes sustainable development in an energy context encouraging improvements in energy efficiency, the generation of renewable energy, the reduction of carbon dioxide emissions from the transport sector as well as the promotion of renewable energy sources and energy efficiency in developing countries
- The Renewable Electricity Directive 10 , which includes an indicative target to increase the proportion of the EU-25’s electricity supplied by renewable sources to 21% in 2010 (14% in 1997), with specific indicative targets for each Member State
- The Biofuels Directive 11 , which includes an indicative target of 5.75% of transport fuels to be biofuels
- The Energy Performance of Buildings Directive 12 , which requires Member States to adopt energy performance standards, will introduce energy labelling of buildings across the EU, along with a requirement to evaluate the opportunities for installing renewable energy systems in buildings above a certain size
- The Cogeneration Directive 13 that aims to provide incentives for the development of cogeneration (also known as combined heat and power (CHP)
- A voluntary commitment 14 by car manufacturer associations to improve CO 2 efficiency of new cars by 25% in 2008/2009 with respect to 1995
- The Landfill of Waste Directive 15 , which will reduce the amount of waste sent to landfill and the production of methane associated with its decomposition
Progress in GHG reduction is, however, still relatively slow. Total aggregate GHG emissions for Annex I Parties to the Kyoto protocol as a whole decreased by 3.3% between 1990 and 2004 (see Figure 2).
The IEA in its World Energy Outlook 2006 report has studied two scenarios considering energy demand and CO 2 emissions 16 .
In a reference scenario, which provides a baseline vision of how energy markets are likely to evolve without new government action to alter underlying energy trends, global primary energy demand increases by 53% between now and 2030. Over 70% of this increase comes from developing countries, led by China and India.
Strong policy action is needed to move the world onto a more sustainable energy path. An alternative policy scenario demonstrates that the energy future can be substantially improved if governments around the world implement the policies and measures they are currently considering. In this scenario, global energy demand is reduced by 10% in 2030 – equivalent to China’s entire energy consumption today. Global CO 2 emissions are reduced by 16% – equivalent to current emissions in the United States and Canada combined.
Based on the assessment reports of the Intergovernmental Panel on Climate Change (UN-IPCC), it is now generally believed that the global temperature rise should be limited to not more than 2° Celsius above the pre-industrial level. The available evidence suggests that beyond this threshold severe impacts could increase markedly. CO 2 concentrations would therefore have to remain well below 550 ppm CO 2 equivalents. Stabilising concentrations at around 450 ppm CO 2 equivalent in the long term would give a 50/50 chance of staying within the 2° Celsius ceiling. To reach this objective, emission reductions by industrialised countries in the order of 15-30% below 1990 levels by 2020, and deeper cuts after that, are needed. Action by developing countries will also be essential, since their emissions are projected to overtake those from developed countries by 2020.
Buildings and climate change
In reducing anthropogenic GHG emissions, measures should be targeted at the major sources. Generally data are available for energy consumption and associated GHG emissions in the sectors related to transport, households, industry and other sectors, including services and agriculture.
Policies have been developed – starting with industry and transport as major sectors of importance. Considering the present urbanisation and the trend for more people to live in urban areas, especially in developing countries, it is realized that the built environment is a sector that should receive more attention regarding its energy use and associated GHG emissions.
Worldwide, 30-40% of energy is used in buildings. Most of it is produced from fossil fuels. On a global level, however, there is a lack of knowledge regarding the building stock and its energy use characteristics. The residential sector accounts for the largest part of the buildings energy use globally, with a share over 90% in developing countries. Data on non-residential building stock is incomplete, even in developed countries 17 & 18 . The USA and Europe have the most complete data set. Buildings account for 40% of the EU ’s energy requirements 19 . For the US the figure is estimated to be somewhat higher at 48% – based on the U.S. Energy Information Administration statistics.
Bottlenecks in defining general guidelines for GHGs reduction in buildings
Although it is now clear that reduction in energy use in the building sector can have a major positive impact on GHG emissions, general measures and global standards are difficult to define20. On a worldwide scale, feasible measures to reduce energy consumption in buildings depend on a number of factors. The energy use of a building is dependent, amongst other things, on the level of development of the country where the building is located, social and economic factors, the climate zone, the building type (residential or commercial) and whether it is a new or old building. Another aspect is the distribution of energy use over the lifecycle. The lifecycle is divided into three phases: construction, maintenance and demolition, where construction includes manufacturing and transport of products, maintenance covers operation of buildings and demolition allows for disposal of waste material.
Most (80-90%) of the energy today is used during the operational phase for heating, cooling and lighting of the buildings. Another part of the energy is related to the embodied energy in buildings. The relative proportions of operating energy and embodied energy will change as new, low energy or zero energy buildings are constructed. In these zero-energy buildings a comfortable interior climate can be maintained without active heating and cooling systems 18, 21, 22 .
Elements to be considered in developing guidelines for new and existing buildings
In developing general guidelines for energy efficiency in new buildings the following might be considered 23 :
- The selection of low-embodied energy materials
- The introduction of passive solutions at design phase (e.g. natural ventilation and orientation)
- The selection of high performance materials and technologies, when applicable (such as energy saving equipment – HVAC, lighting, computers, refrigerators, etc – and clean electricity such as PV cells)
- The introduction of advanced monitoring systems (e.g. to check the use of electricity by the building to detect abnormalities and correct them)
In the OECD, less than 1% of buildings are newly built every year. New buildings use less energy than existing ones and there will be a need for differentiating building codes – with energy requirements for new buildings and those for buildings to be renovated. Considering the rapidly increasing technological developments in this field, the year of construction and the type of building are important indicators in defining the measures and monitoring progress in energy reduction24
Progress in the EU
The European Union has made considerable progress in defining a specific action programme targeted at the buildings sector with specific reference to building performance requirements and very low energy buildings (“passive houses”) 25
The Energy Performance of Buildings Directive (2002/91/EC) can play a key role in realising the savings potential in the buildings sector, which is estimated at 28%, and which can, in turn, reduce total EU final energy consumption by around 11%. The European Commission will propose expanding the scope of the Energy Performance of Buildings Directive substantially in 2009, after its complete implementation. It will also propose EU minimum performance requirements for new and renovated buildings (kWh/m 2 ). For new buildings, the Commission will also, by the end of 2008, develop in dialogue with Member States and key stakeholders, a strategy for very low energy or passive houses – to encourage more widespread deployment of such houses by 2015.
Important role for sustainability performance and rating systems
The existing standards for sustainable buildings, including energy performance have a strong local, national or regional character, such as those in the EU. Although a complex task, general baselines and guidelines for various aspects of building performance need to be established. These can then be used to develop national and regional standards or legislation. Such baselines should not only emphasize energy efficiency but also climate change impact, materials use and efficiency, waste generation, water efficiency, ease of recycling, replacement and maintenance, integration with social systems, minimum consideration with social systems, minimum considerations with for fragile ecosystems 20 .
Next to development of baselines for regulatory control purposes, attention should also be given to the systems based on voluntary approaches. The US experience with promoting Leadership In Energy and Environmental Design (LEED) has proved that market forces are a powerful tool in introducing sustainable and energy efficient buildings. LEED is one of the sustainability rating systems that also include energy performance in buildings. Other related initiatives have developed a significant body of knowledge that proves that sustainable behaviour is profitable in many ways – not only in energy savings. It seems that the profit motive is the most powerful motivator known 23 .
The French HQE method (High Environmental Quality) is a voluntary method that deals with the construction of certified high environmental quality building – using a lifecycle analysis to take into account the direct and associated impacts. This French approach is starting to be adapted and disseminated in other countries.
Other rating systems include Breeam and Ecohomes (UK), SPeAR (UK),Casbee (Japan), EcoEffects (Sweden), Green Building Challenge (International) 24 . The International Federation of Consulting Engineers has developed a system for Project Sustainability Management (FIDIC-PSM, http://www.fidic.org/psm), in which the set of sustainability performance indicators can be adjusted and aligned with other rating systems 26 .
Since this article was written, the IPCC report on the physical science basis of climate change has been published. It states: “Most of the observed increase in globally averaged temperatures since the mid-20th century is very likely due to the observed increased in anthropogenic greenhouse gas concentrations.”
1 European Community. Fact sheet climate change. August, 2005, 4 pp. http://ec.europa.eu/environment/climat/pdf/cc_factsheet_aug2005.pdf
2 Energy and environment in the European Union. Tracking progress towards integration European Environment Agency. 2006-52pp. ISBN 92-9167-877-5
3 Stern Report Stern Review Report on the Economics of Climate Change 2006. http://www.hm-treasury.gov.uk/independent_reviews/stern_review_ economics_climate_change/sternreview_index.cfm
4 European Community. Commission Communication of 9 February 2005 “Winning the battle against global climate change” [COM(2005) 35 – Official Journal C 125 of 21 May 2005] http://eur-lex.europa.eu/LexUriServ/site/en/ com/2005/com2005_0035en01.pdf., and memo/05/42, Brussels, 9 February 2005. http://www.europa.eu/rapid/pressReleasesAction do?reference= MEMO/0542&format=HTML&aged=0&language=EN&guiLanguage=en
5 European Community: Council Decision 2002/358/EC of 25 April 2002 concerning the approval, on behalf of the European Community, of the Kyoto Protocol to the United Nations Framework Convention on Climate Change and the joint fulfilment of commitments there under.
6 Communication from the Commission on the implementation of the first phase of the European Climate Change Programme. COM(2001)580 final of 23.10.2001 – http://europa.eu.int/eur-lex/en/com/pdf/2001/com2001_ 0580en01.pdf
7 Directive 2003/87/EC (OJ L of the 25.10.2003) of the European Parliament and of the Council of 13 October 2003 establishing a scheme for greenhouse gas emission allowance trading within the Community and amending Council Directive 96/61/EChttp://europa.eu.int/scadplus/leg/en/ lvb/l28012.htm
8 Directive 2004/101/EC (OJ L 338 of 13.11.2004) of the European Parliament and of the Council of 27 October 2004 amending Directive 2003/87/EC establishing a scheme for greenhouse gas emission allowance trading within the Community, in respect of the Kyoto Protocol’s project mechanisms http://europa.eu.int/scadplus/leg/en/lvb/l28012.htm
9 Decision 1230/2003 (OJ L 176 of 15.07.2003) of the European Parliament and of the Council of 26 June 2003 adopting a multiannual programme for action in the field of energy: ‘Intelligent Energy- Europe’ (2003-2006)http:// europa.eu.int/eur-lex/pri/en/oj/dat/2003/l_176/l_17620030715en00290036. pdf
10 Directive 2001/77/EC (OJ L 283 of 27.10.2001) of the European Parliament and of the Council of 27 September 2001 on the promotion of electricity produced from renewable energy sources in the internal electricity market http://europa.eu.int/eur-lex/pri/en/oj/dat/2001/l_283/l_ 28320011027en00330040.pdf
11 Directive 2003/30/EC (OJ L 123 of 17.5.2003) of the European Parliament and of the Council of 8 May 2003 on the promotion of the use of biofuels or other renewable fuels for transport http://europa.eu.int/scadplus/leg/en/lvb/ l21046.htm
12 Directive 2002/91/EC (OJ L 001 of 04.01.2003) of the European Parliament and of the Council of 16 December 2002 on the energy performance of buildings http://europa.eu.int/scadplus/leg/en/lvb/l27042.htm
13 Directive 2004/8/EC (OJ L 052 of 21.02.2004) of the European Parliament and of the Council of 11 February 2004 on the promotion of cogeneration based on a useful heat demand in the internal energy market and amending Directive 92/42/EEC .http://europa.eu.int/scadplus/leg/en/lvb/l27021.htm
14 Voluntary commitment car manufacturers. http://europa.eu.int/comm/ environment/co2/co2_home.htm
15 Council Directive 1999/31/EC (OJ L 182 of 16.07.1999) of 26 April 1999 on the landfill of waste.http://europa.eu.int/eur-lex/pri/en/oj/dat/1999/l_182/l_ 18219990716en00010019.pdf
16 World Energy Outlook 2006. International Energy Agency Summary and Conclusions. www.iea.org.
17 Macmillan, Sebastian and Kohler, Jonathan. 2004. Modelling energy use in the global building stock: a pilot survey to identify available data sources. Tyndall Centre Technical Report No. 6. Tyndal Centre for Climate Change Research. Cambridge
18 Buildings and Climate Change. Status, challenges and opportunities. UNEP SBCI Strategic Reports. Final Draft. 2006. UNEP/DTIE
19 Action Plan to Improve Energy Efficiency in the European Community. Communication from the Commission to the Council, the European Parliament, the Economic and Social Committee and the Committee of the Regions. Brussels, 26.04.2000 COM(2000) 247 final
20 UNEP. Sustainable Building and Construction Initiative. 2006 Information Note UNEP, DTIE, Paris, France, 12 pp
21 Measures of Sustainability. Canadian Architects. http://www. canadianarchitect.com/asf/perspectives_sustainibility/measures_of_ sustainablity/measures_of_sustainablity_embodied.htm
22 Cole, R.J. and Kernan, P.C. (1996), Life-Cycle Energy Use in Office Buildings, Building and Environment, Vol. 31, No. 4, pp. 307-317.
23 Energy Use and Greenhouse Gas Emissions from Construction and Buildings Review prepared by Sustainable Building and Construction Initiative (SBCI) Climate Change Think Tank Working Group (TTWG), UNEP SBCI 2006. UNEP, DTIE, Paris, France
24 Jens Laustsen Developing future building energy performance indicators WorkshopIEA, Paris: 27-28 November 2006 http://www.iea.org/Textbase/ work/workshopdetail.asp?WS_ID=279
25 Commission of the European Communities.Action Plan for Energy Efficiency: Realising the Potential. COM(2006)545 final. Brussels, 19.10.2006 http://ec.europa.eu/energy/action_plan_energy_efficiency/doc/com_2006_ 0545_en.pdf
26 Project Sustainability Management. International Federation of Consulting Engineers (FIDIC). Guidelines. 2004. 40 pp. www.fidic.org/psm.
Published: 01st Mar 2007 in AWE International