IPCC Fourth Assessment Report: Climate Change 2007
Climate Change 2007: Working Group III: Mitigation of Climate Change Solar retrofits of residential, institutional and commercial buildings

Solar retrofit performed in Europe under the IEA Solar and Cooling Program achieved savings in space heating of 25–80% (Harvey, 2006, Chapter 14). The retrofit examples described above, while achieving dramatic (35–75%) energy savings, rely on making incremental improvements to the existing building components and systems. More radical measures involve re-configuring the building so that it can make direct use of solar energy for heating, cooling and ventilation. The now-completed Task 20 of the IEA’s Solar Heating and Cooling (SHC) implementing agreement was devoted to solar retrofitting techniques.

Solar renovation measures that have been used are installation of roof- or façade-integrated solar air collectors; roof-mounted or integrated solar DHW heating; transpired solar air collectors, advanced glazing of balconies, external transparent insulation; and construction of a second-skin façade over the original façade. Case studies are presented in Boonstra and Thijssen (1997), Haller et al. (1997) and Voss (2000a), Voss (2000b) and are summarized in Harvey (2006), Chapter 14).