Buildings account for approximately 40% of energy demand in the European Union (EU) and it is estimated that energy efficiency measures currently accessible could cost-effectively save around 28% of this (Ekins & Lees, 2008). Buildings in the UK are subject to EU regulations. The primary legislation affecting energy use and energy efficiency in the buildings sector in the EU is the Energy Performance of Buildings Directive (EPBD) (Ekins & Lees, 2008). Introduced in December 2002, the EPBD aims to exploit the potential energy savings in the building sector. All new buildings covered by the EPBD have to meet minimum energy performance
requirements and produce Energy Performance Certificates (Bio Intelligence Service et al, 2013). However, due to the wide variety in buildings across Europe, it is difficult to implement a common approach at EU level and transposition of the Directive into national law has faced difficulties and delays since 2002 (Ekins & Lees, 2008). By 2008, most Member States had created national law around the EPBD, but its implementation is not necessarily ensured (Ekins & Lees, 2008). Therefore, it can be said that while policy is attempting to direct change, in reality this is a slow process.
There has been much focus on the energy efficiency of dwellings in policy and regulation (Pilkington et al, 2011). As outlined in the introduction to this thesis, with
30 buildings accounting for a large proportion of total energy demand in the UK,
achieving carbon reduction targets requires a significant contribution from the buildings sector with domestic dwellings as an area of focus (Kane et al, 2011; Skea, 2012). The domestic sector accounts for around 27% of all UK CO2 emissions (Boardman, 2007; Hamza & Gilroy, 2011; Utley & Shorrock, 2008) and is an area considered very cost-effective to treat in terms of carbon abatement (Smith & Swan, 2012). The UK housing stock is subject to Building Regulations, with the first
mandatory regulations in England being implemented in 1966 (Dowson et al, 2012). Since the energy crisis of 1973, continual revisions to Building Regulations have caused energy efficiency targets for all new buildings to be increasingly stringent (Dowson et al, 2012).
Since 2006, all new dwellings have been required to demonstrate design compliance using the Standard Assessment Procedure (Dowson et al, 2012). The Standard Assessment Procedure (SAP) was formulated by the Building Research
Establishment (BRE) as the UK Government’s methodology for assessing the energy rating of dwellings (Murphy et al, 2010). Calculations are based on house type and layout of the property, along with heating and insulation measures installed (Wright, 2004). A SAP rating result is given on a scale of 1-100 (Dowson et al, 2012); a score of 80 and above represents an energy efficient home (Wright, 2004) with 100 representing net zero carbon (McManus et al, 2010). There is currently a target for all new buildings to be net zero carbon by 2016, with a more stringent target of 2015 for social housing dwellings (Jenkins, 2010).
A policy was initiated in 2007 to combat these targets for new housing. The Code for Sustainable Homes was introduced to manage a ‘step-change’ programme for improving the overall environmental performance of new-build housing (McManus et al, 2010). Codes are ratings, banded levels 1 to 6, which contain standards and requirements to be achieved in order to reduce carbon emissions and promote higher standards of sustainable design than currently set out by the building
regulations (DCLG, 2013). The Code is not a set of obligatory regulations; however, the level 3 energy standard is now incorporated into the building regulations and,
31 moreover, affordable housing funded by the Homes and Communities Agency is required to be built to code level 3.
Despite regulations for better energy efficiency of all new buildings, such as through the EPBD, two key issues remain challenging. The first challenge is the increase in domestic buildings. The overall number of households in the UK is projected to rise over the next few decades, from an estimated 21.5 million in 2006 to 27.8 million in 2031 (DEFRA, 2009).This increase in number of households can be attributed to an observed expanding population and decreasing household sizes (Ravetz, 2008). It was stipulated that the UK Government was attempting to address an overall shortfall of housing by increasing building, potentially by 200,000 net units per year by 2016 (Power, 2008; Whitehead & Scanlon, 2007). This increase of output was to include around 30% affordable housing, both social renting and low cost home ownership (Whitehead & Scanlon, 2007). An independent assessment, the Barker review, recommended a need for increased levels of social housing in order to deal with the growth in need for social housing and the consequences of diminished stock due to the ‘Right to Buy’ scheme (DCLG, 2006).
It can be deduced that an increased amount of housing would most likely result in further energy consumption. This can be assumed from the indirect consequences of more housing, such as higher expectations of occupant comfort from the indoor environment, people working from home and greater instances of more electronic equipment (Cockroft & Kelly, 2006). The Energy Saving Trust calculated that
ownership and use of domestic appliances doubled between 1971 and 2002 (Energy Saving Trust, 2006); it can be expected that more households would further
increase the number of appliances in use.
The second of these challenges is that over two-thirds of the UK housing stock that will exist in 2050, the deadline for significant targets, is already built (Power, 2008; Ravetz, 2008; Wright, 2008). Therefore, the majority of the domestic building stock by 2050 will not be affected by this new-build legislation. It is proposed to raise the average SAP rating, the measurement of the energy performance of dwellings, of the current UK building stock to 80 by 2050, in line with modern building standards
32 (Dowson, 2012). This proposed target indicates a need for focusing attention on energy efficiency in existing buildings and, therefore, retrofit measures will be crucial for the improvement of these dwellings. The following graph in Figure 2 shows current data of SAP ratings of the English housing stock and demonstrates the work that needs to be done to bring the existing housing stock up to a SAP rating of 80.
Figure 2: SAP ratings across the English housing stock (Dowson et al, 2012)
The UK has some of the oldest and most inefficient residential properties in Europe (Pendleton & Viitanen, 2011), as evident in the graph above (Figure 2) and even the developed world (Hamza & Gilroy, 2011).Only around one-fifth of homes in England have been built since 1980 (Pendleton & Viitanen, 2011). Thus, there are implications for the energy efficiency of housing in the UK for the foreseeable future. Housing in the social sector is already more energy efficient than housing in the private sector, with an average SAP rating of 57 against a SAP rating of 47 in the private sector (Ravetz, 2008). This may be attributed to the opportunity social housing offers in terms of economies of scale and the availability of grant funding to carry out work on a larger target of properties. In the private sector, it is the responsibility of each householder to initiate modifications to their home and to manage the outlay, as they own their property. In social housing, the landlord oversees management of a large amount of properties and is accountable for the cost of improvements; therefore, a widespread area of properties can be targeted and the responsibility and decisions lie less with the householder.
33 Furthermore, social housing organisations are under obligations to improve and maintain the standard of the social housing stock. A key standard driving national improvements to the existing housing stock in the social sector is the Decent Homes Standard (DHS). This standard was introduced in 2000, consisting of four key indicators known as the DHS criteria (Kempton, 2004), in order to bring all social housing rapidly to the standard level of current building regulations
(Boardman, 2007). Under this policy, a home was deemed to be ‘decent’ if it meets the current fitness standard, is in a reasonable state of repair, has reasonably modern facilities and services and a reasonable degree of thermal comfort
(Kempton, 2004; Wright, 2004). The latter of these criteria indicates the relevance of this research addressing thermal comfort and sustainability. The standard is driving improvements in thermal efficiency of the social housing stock and energy efficiency improvements are being implemented in order to meet the standard, including renewable technologies; therefore, an increase of renewable heating technology installations can be expected.
This policy set a target of ensuring all dwellings met the Decent Homes Standard by 2010 (DCLG, 2006; Ginsburg, 2005; Kempton, 2004). By the end of 2010, 92% of social housing met the DHS of being warm and weatherproof with reasonably modern facilities (Homes and Communities Agency, 2013). A Decent Homes Backlog Programme was established to provide further funding between 2011 and 2015 to help social housing organisations complete their programmes to meet the DHS (Homes and Communities Agency, 2013). To date, the social housing sector is likely to have moved closer towards the target of all existing dwellings meeting the DHS, but not reached it yet. However, there is a lack of available data on the extent of progress; this is an assumption based on the availability of funding and lapsed time period. Arguably, there is still Decent Homes work to be completed within the social housing sector.
As a consequence of infrastructure, management and policy drivers, the social sector is in a position to address their properties and increase their energy efficiency. As indicated by national performance ratings, they are already doing so. Not all homes are there yet though, indicating a need for continued improvement.
34 Whilst this may amount to a small percentage, this may represent thousands of homes and, therefore, thousands of people living in non-decent dwellings.
Furthermore, it should be considered that the Decent Homes Standard is a holistic standard addressing the fitness of a property for inhabitancy; it is not predominantly driven by a goal to reduce domestic carbon emissions. Therefore, further work is arguably required to address energy usage and carbon emissions of the social housing stock in relation to other policies and targets.