on the literature, resulting in emissions between the B2 and. A1B SRES
scenarios ...... six-unit apartment building during most of the summer if the high
risk of ...
6 Residential and commercial1 buildings Coordinating Lead Authors: Mark Levine (USA), Diana Ürge-Vorsatz (Hungary)
Lead Authors: Kornelis Blok (The Netherlands), Luis Geng (Peru), Danny Harvey (Canada), Siwei Lang (China), Geoffrey Levermore (UK), Anthony Mongameli Mehlwana (South Africa), Sevastian Mirasgedis (Greece), Aleksandra Novikova (Russia), Jacques Rilling (France), Hiroshi Yoshino (Japan)
Contributing Authors: Paolo Bertoldi (Italy), Brenda Boardman (UK), Marilyn Brown (USA), Suzanne Joosen (The Netherlands), Phillipe Haves (USA), Jeff Harris (USA), Mithra Moezzi (USA)
Review Editors: Eberhard Jochem (Germany), Huaqing Xu (PR China)
This chapter should be cited as: Levine, M., D. Ürge-Vorsatz, K. Blok, L. Geng, D. Harvey, S. Lang, G. Levermore, A. Mongameli Mehlwana, S. Mirasgedis, A. Novikova, J. Rilling, H. Yoshino, 2007: Residential and commercial buildings. In Climate Change 2007: Mitigation. Contribution of Working Group III to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change [B. Metz, O.R. Davidson, P.R. Bosch, R. Dave, L.A. Meyer (eds)], Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA.
1 The category of non-residential buildings is referred to by different names in the literature, including commercial, tertiary, public, office, and municipal. In this chapter we consider all non-domestic residential buildings under the “commercial” sector.
Residential and commercial buildings
Chapter 6
Table of Contents Executive Summary................................................... 389 6.1
Introduction....................................................... 391
6.2 Trends in buildings sector emissions .......... 391 6.3 Scenarios of carbon emissions resulting from energy use in buildings .................................. 392
6.6 Co-benefits of GHG mitigation in the residential and commercial sectors. ............ 416 6.6.1 Reduction in local/regional air pollution............. 416 6.6.2 Improved health, quality of life and comfort. ..... 416 6.6.3 Improved productivity . .................................... 417 6.6.4 Employment creation and new business opportunities. .................................................. 417
6.4 GHG mitigation options in buildings and equipment ......................................................... 393
6.6.5 Improved social welfare and poverty alleviation 418
6.4.1 Overview of energy efficiency principles. .......... 394
6.6.7 Summary of co-benefits................................... 418
6.4.2 Thermal envelope. ........................................... 395 6.4.3 Heating systems.............................................. 396 6.4.4 Cooling and cooling loads................................ 397 6.4.5 Heating, ventilation and air conditioning (HVAC) systems........................................................... 399 6.4.6 Building energy management systems (BEMS). 400 6.4.7 Active collection and transformation of solar energy. ............................................................ 401 6.4.8 Domestic hot water.......................................... 402 6.4.9 Lighting systems.............................................. 402 6.4.10 Daylighting....................................................... 402 6.4.11 Household appliances, consumer electronics and office equipment. ...................................... 403 6.4.12 Supermarket refrigeration systems. .................. 404 6.4.13 Energy savings through retrofits . ..................... 404 6.4.14 Trade-offs between embodied energy and operating energy.............................................. 405 6.4.15 Trade-offs involving energy-related emissions and halocarbon emissions. ..................................... 405 6.4.16 Summary of mitigation options in buildings ...... 406
6.5 Potential for and costs of greenhouse gas mitigation in buildings.................................... 409 6.5.1 Recent advances in potential estimations from around the world.............................................. 409
6.6.6 Energy security................................................ 418
6.7 Barriers to adopting building technologies and practices that reduce GHG emissions 418 6.7.1 Limitations of the traditional building design process and fragmented market structure. ....... 418 6.7.2 Misplaced incentives ....................................... 419 6.7.3 Energy subsidies, non-payment and theft ........ 419 6.7.4 Regulatory barriers........................................... 420 6.7.5 Small project size, transaction costs and perceived risk . ................................................ 420 6.7.6 Imperfect information....................................... 420 6.7.7 Culture, behaviour, lifestyle and the rebound effect............................................................... 420 6.7.8 Other barriers................................................... 421
6.8 Policies to promote GHG mitigation ...........in buildings............................................................. 421 6.8.1 Policies and programmes aimed at building construction, retrofits, and installed equipment and systems........................................................... 421 6.8.2 Policies and programmes aimed at appliances, lighting and office/consumer plug loads ........... 423 6.8.3 Cross-cutting policies and programmes that support energy efficiency and/or CO2 mitigation in buildings ..................................................... 425 6.8.4 Policies affecting non-CO2 gases. .................... 430
6.5.2 Recent advances in estimating the costs of GHG mitigation in buildings. ..................................... 414
6.8.5 Policy options for GHG abatement in buildings: summary and conclusion. ................................ 431
6.5.3 Supply curves of conserved carbon dioxide...... 414
6.9 Interactions of mitigation options with vulnerability, adaptation and sustainable development. ..................................................... 435
6.5.4 Most attractive measures in buildings............... 415 6.5.5 Energy and cost savings through use of the Integrated Design Process (IDP)....................... 416
6.9.1 Interactions of mitigation options with vulnerability and adaptation.............................. 435 6.9.2 Synergies with sustainability in developing countries ......................................................... 436
6.10
Critical gaps in knowledge. ......................... 437
References.................................................................... 437 388
Chapter 6
Residential and commercial buildings
EXECUTIVE SUMMARY In 2004, emissions from the buildings sector including through electricity use were about 8.6 GtCO2, 0.1 GtCO2eq N2O, 0.4 GtCO2-eq CH4 and 1.5 GtCO2-eq halocarbons (including CFCs and HCFCs). Using an accounting system that attributes CO2 emissions to electricity supply rather than buildings end-uses, the direct energy-related carbon dioxide emissions of the building sector are about 3 Gt/yr. For the buildings sector the literature uses a variety of baselines. Therefore a baseline was derived for this sector based on the literature, resulting in emissions between the B2 and A1B SRES scenarios, with 11.1 Gt of emissions of CO2 in 2020 and 14.3 GtCO2 in 2030 (including electricity emissions but omitting halocarbons, which could conceivably be substantially phased out by 2030). Measures to reduce greenhouse gas (GHG) emissions from buildings fall into one of three categories: reducing energy consumption and embodied energy in buildings, switching to low-carbon fuels including a higher share of renewable energy, or controlling the emissions of non-CO2 GHG gases. This chapter devotes most attention to improving energy efficiency in new and existing buildings, which encompasses the most diverse, largest and most cost-effective mitigation opportunities in buildings. The key conclusion of the chapter is that substantial reductions in CO2 emissions from energy use in buildings can be achieved over the coming years using mature technologies for energy efficiency that already exist widely and that have been successfully used (high agreement, much evidence). A significant portion of these savings can be achieved in ways that reduce life-cycle costs, thus providing reductions in CO2 emissions that have a net benefit rather than cost. However, due to the long lifetime of buildings and their equipment, as well as the strong and numerous market barriers prevailing in this sector, many buildings do not apply these basic technologies to the level life-cycle cost minimisation would warrant (high agreement, much evidence). Our survey of the literature (80 studies) indicates that there is a global potential to reduce approximately 29% of the projected baseline emissions by 2020 cost-effectively in the residential and commercial sectors, the highest among all sectors studied in this report (high agreement, much evidence). Additionally at least 3% of baseline emissions can be avoided at costs up to 20 US$/tCO2 and 4% more if costs up to 100 US$/tCO2 are considered. However, due to the large opportunities at lowcosts, the high-cost potential has been assessed to a limited extent, and thus this figure is an underestimate (high agreement, much evidence).
Using the global baseline CO2 emission projections for buildings, these estimates represent a reduction of approximately 3.2, 3.6 and 4.0 GtCO2/yr in 2020, at zero, 20 US$/tCO2 and 100 US$/tCO2 respectively. Our extrapolation of the potentials to the year 2030 suggests that, globally, about 4.5, 5.0 and 5.6 GtCO2 at negative cost,
