M. Gillott and C. Spataru,     University of Nottingham, UK

26.1 Introduction

Buildings are the major consumers of energy and therefore major contributors to the increase in greenhouse gas emissions leading to global climate change. There has been a considerable overall increase in the total final energy consumption associated with buildings during the last 30 years.

The existing building stock is responsible for over 40% of the world’s total final energy consumption, and accounts for 24% of world CO₂ emissions (IEA, 2006). Using current, commercially viable technology, much of this consumption could be avoided through improved efficiency of building energy systems (De T’Serclaes, 2007, p. 4). The effective refurbishment of the building stock has significant potential for achieving large savings in primary energy consumption and associated CO₂ emissions.

Figures 26.1(a) and (b) show the total final consumption worldwide in 1973 and 2006. More of this data may be found in the International Energy Agency (IEA) website. Over-use of energy in buildings due to inefficiencies is a global problem. As nations develop their reliance on energy, its use in buildings will inevitably increase. As Fig. 26.1 shows, there has been a significant increase in the share of global energy consumption in China and Asia. Between 1973 and 2006 the share of global primary energy consumption increased by 7.1% and 5% for China and Asia, respectively. The Organisation for Economic Co-operation and Development (OECD) nations’ share of energy consumption decreased by approximately 13.3% over the same time period. The global requirement to increase the effciency of the world’s building stock will require tailored solutions for individual nations based on local features such as building typology, building use and local climatic conditions. Figure 26.2 shows the world market energy consumption including projections, 1980–2030. In addition to the provision of energy from non-fossil fuel sources, energy efficiency will also need to play a key role in mitigating the predicted rises.

Buildings are used mainly to provide shelter, places for commerce, work and leisure. Studies in the USA and elsewhere indicate that approximately 93% of people’s time is spent indoors, 5% of time is spent in transit and only 2% outdoors (Otson and Fellin, 1992). Most human activity happens in buildings, and hence they are responsible for the majority of the energy use and implicit greenhouse gas emissions. From the worldwide total energy consumption, the domestic, commercial sectors and the Local Government Authority buildings represent the most important areas for decreasing primary energy consumption through improved energy efficiency measures.

The residential sector is the predominant worldwide user of energy. Water heating, space heating and cooking, appliances, cooling and refrigeration represent the major uses of energy in the residential sector. Similarly, the commercial sector uses energy for lighting, heating and cooling of buildings, for cooking, for appliances (such as computers and office machines), efficient appliances and building design being the key factors in comfort and energy savings. The efficient use of energy through good environmental building design and use of efficient HVAC systems and appliances are therefore key factors for saving energy. Local Government Authorities have similarities with the commercial sector, in terms of their energy use for the operation of public buildings and street lighting, etc. In each of these cases, the refurbishment of the existing building stock could significantly help reduce global primary energy consumption and associated CO₂ emissions. The process of refurbishment will generally only take place when national governments, and/or local and public authorities, get involved by encouraging and promoting energy savings through the provision of information and incentives to use energy saving measures such as insulation and energy appliances. When deciding on refurbishment measures to reduce a building’s energy consumption, it is important to first know where the energy is used. The breakdowns of consumption by end use in the EU (Bowie and Jahn, 2003) and the USA (US Department of Energy, 2000) in the residential and commercial sectors are given in Fig. 26.3.

Space heating is the largest component of energy use, requiring 57% in the EU and 49.3% in the USA of the primary energy demand for the residential sector and 52% in the EU and 23.3% in the USA for the commercial sector. Water heating follows at 25% in the EU, while in the USA, cooking makes up 25% of the domestic demand, accounting for the largest incremental growth in both production and consumption. Commercial buildings show a higher percentage for lighting and appliances than residential buildings, especially for the USA, as well as a significant percentage of energy used for other uses. The differences will largely be due to the building use, location (climate), typology, size and envelope construction. Understanding these differences is vitally important when deciding on appropriate refurbishment solutions aimed at reducing energy consumption in different building types located in different climates.

The energy consumption by end-users in Canada has similarities with consumption data from the USA. Space heating is the main consumer of energy, followed by water heating and appliances in both sectors (Fig. 26.4). The percentages given in Figs 26.3 and 26.4 vary depending on the building construction (age and size), installations, as well as climate (different climate in different regions in USA or Canada, as well as in different countries in Europe).

The next case (Fig. 26.5) shows the differences in energy consumptions in Australia in different periods of time, as well as the forecast for 2020. As can be seen from Fig. 26.5, the forecast of overall energy intensity for space heating shows a decrease by 5% in 2020 compared with 1990. This decrease may occur for two main reasons: firstly, because more people choose natural gas over fuel oil systems, and secondly, because natural gas furnaces become more efficient. The energy consumption for water heating is forecast to reduce by 5% in 2020 compared with 2007. The decreased proportion of energy use for water heating could be due to the use of gas and solar technologies, as well as the use of efficient appliances, such as front-loading washing machines and low-flow shower heads. Cooking energy consumption represents a small percentage of the total energy consumption and over time will stay the same. Forecast predictions show a proportional increase in space cooling and appliance energy consumptions. The increase in space cooling could be due to the reduction in the cost of air conditioning units and people’s desire for these systems along with hotter dryer summers (already a possible consequence of global climate change). The balance of energy use has also changed due to the rise and predicted rise in appliance use. The proportion of energy use for appliances increased by 8% in 2007 compared with 1990. This is due to a rapid growth in minor appliances, and consumer electronics such as laptops, mobile phones and games consoles.

From data for different parts of the world, electricity is the fastest-growing form of energy. This growth in electricity consumption is driven by the increased number of electrical appliances used across the world, as well as the increased use of air conditioners. Electricity and heat represents 86% of the total global CO₂ emissions (du Can and Price, 2008).

As shown above, the energy use in buildings is largely associated with space heating and hot water provision as well as lights and appliances. Reducing energy consumption associated with these uses alone offers huge potential for saving energy in the residential, commercial and public sector. These savings will also help countries meet their own targets in accordance with the Kyoto protocol (all nations must contribute to a global reduction in carbon emissions). On a global scale, industry and research establishments (e.g. universities and government institutes) are all working to provide economic solutions to improve the energy efficiency of buildings. These solutions will constitute a potential investment in natural and human resources and can represent a potential source of private and public investment. Refurbishment solutions not only offer potential for significantly reducing energy consumption and associated CO₂ emissions. The refurbishment of buildings also has other benefits such as employment opportunities, increasing the aesthetic quality of the existing stock, improved comfort conditions, reduced health problems for occupants, reduced running costs and potentially reducing the number of families suffering from fuel poverty.

This process requires significant capital investment, but at the same time it could represent a significant potential for savings. Strategies, such as creating potential for loans for energy efficiency with a low or non-existent payback rate tax could leverage support from the general public, as well as investors. Refurbishment solutions will require education strategies involving training and information for public, sales people, maintenance personnel and consumers.

26.2 Change of use in buildings

Refurbishment has a key role to play in the change of use of buildings. Instead of demolishing buildings that are no longer used, it may be possible to refurbish them for another use. The change of use in existing buildings could keep existing neighbourhoods intact, occupied and safeguarded for the future. For communities, their buildings can represent the historic, cultural and visual fabric of a neighbourhood. The re-use of a building can be achieved if their primary structural integrity is intact. This process is used worldwide, especially in historical buildings with remarkable architecture. The material interventions used to change the function of buildings may have similarities to the original building.

Different changes could be applied to buildings, e.g. the conversion of offices and public buildings for residential use, or the conversion of factories or large industrial units for public use such as museums or art galleries. Conversions will encompass specific requirements which must be considered and included in the upgrading of the building, e.g. fire precautions, hygiene, access to and use of buildings, storage facilities. The conversion is also an excellent opportunity to increase the energy performance of the building during the refurbishment process. Additionally the change of use of a building in an existing community should address the cultural aspects, the heritage and the acceptance by the community.

In the early post-communism era (1990s) the economical reconstruction began for the Eastern European countries. Taking the particular case of the industrial building we can say that many of these have been abandoned after the companies that owned them were closed down. Some of them have been re-used mainly as storage depots for the goods imported from Western Europe and more recently others have been used as production places due to their low cost and immediate availability.

In many cases these buildings should be saved and restored since most of them form part of the heritage of the nation. The value of these buildings is found in their architectural or structural form, uniqueness or even due to the fact that they were conceived by a famous architect. However, it is not always economic to take this approach due to the building’s location, size, capacity and the technical requirements associated with the conversion. The first case study below is an example of a conversion project which also addresses environmental concerns, while the subsequent two case studies are examples of refurbishment of residential blocks.

26.3 Approaches to low carbon retrofit systems/technologies

Human behaviour plays an important role in the impact of global climate change, as concluded in the Fourth IPCC Assessment Report ‘Climate Change 2007’ by the Intergovernmental Panel on Climate Change (IPCC, 2007). The general tendencies are:

Relative to 1990, temperatures worldwide for 2100 are expected to increase by 1–6 °C depending on which study you refer to. However, there is a common consensus that temperatures will definitely rise. Therefore the change in outside temperature will provoke changes in the internal temperature, which can affect the building materials. This could have consequences in the resistance of existing building stock and therefore the structural systems may need to be adapted. The increase in temperature with warmer summers and the increase in the quantity of precipitation could lead to overheating and flooding. In the case of dwellings, these are overheated when they reach 28 °C or more for 1% of occupied hours in living areas (TRCCG, 2008). It is therefore also important to ensure that any refurbishment addresses the potential impact of a warming climate. Refurbishment design should be future proofed so that buildings refurbished today will not have a tendency to overheat in the future.

The variety of climates, different types of buildings and different energy conservation technologies implemented differs from one country to another. Therefore it is difficult to generalise the results based on different studies on different buildings. For example, in the UK, if you were to consider an energy efficiency domestic refurbishment, some or all of the following measures should be taken into consideration:

In the UK there are still a considerable number of uninsulated homes, probably for financial reasons and the inconvenience caused by the possible disruption to the homeowner. Depending on the thickness and type of insulation installed, the cost varies as does the reduction in energy bills. It is recommended to insulate the walls and floor at the same time and to seal the gaps with caulking to reduce the infiltration heat loss. In addition to reduced fuel bills, the additional benefits for the homeowner from insulating their homes include increased comfort, reduction of draughts, and maintaining a constant temperature throughout the home.

Insulation plays an important role in the overall building energy consumption. Different materials can be used to insulate, the most common being those with a mineral base, e.g. glass fibre and mineral wool, rock wool, vermiculite, perlite and expanded clay, and those based on porous, polymeric materials, e.g. expanded polystyrene, extruded polystyrene or polyurethane. There are also natural organic-based insulators, such as cork, cellular wool, linen tow, cotton and coco fibre. Many of the latter materials are made from recyclable products.

As previously stated, the type and quantity of material will have an impact on the overall insulation properties of the building. Designers should also consider where and how the insulation material is installed. Buildings constructed with heavyweight materials tend to be better regulators of internal temperature due to their inherent ability to provide temperature buffering. This quality is often referred to as thermal mass which provides high thermal inertia – an ability to store heat within the material which minimises the heat variation of the air inside the building. A low inertia building, on the other hand, will rapidly rise and fall in temperature depending on outside temperature or solar gain. Some insulation materials and some building options favour a high inertia while others do not (De T’Serclaes, 2007). If the thermal mass of the building is isolated due to the addition of internal insulation lining the internal surfaces, there may be an adverse effect on internal temperatures and comfort conditions.

When sealing a building, attention must be paid to the gaps around badly fitted windows or doors. These can potentially cause more air leakage than the window itself. Virtually any opening such as letterboxes, keyholes, cat flaps, loft hatches, open fireplaces and even superfluous air bricks can contribute to ‘leakiness’.

Unfortunately, existing buildings are often expensive to operate in terms of energy costs and can have indoor environmental quality problems. Most old houses, for example, are likely to have old boilers, which have significantly lower thermal performance than today’s boiler units. It is estimated that in the EU there were around 10 million boilers in residential buildings more than 20 years old (Bowie and Jahn, 2003). When an old boiler is replaced with a more efficient one, significant savings in energy can be achieved. Boiler controls can also help to achieve maximum energy saving potential. A smart room thermostat which turns the boiler and heating pump off when the temperature has reached the required level can improve the energy savings level. Therefore programmers or time switches are useful, allowing the user to set the times when heating and hot water are required. In addition to the conventional energy efficiency solutions, designers should also consider the use of systems which make use of renewable sources, such as sun, wind, biomass, etc. Table 26.1 shows the predicted domestic energy savings for various measures.

In most cases the electricity consumption for lighting represents between 15 and 20% of the electricity bill. The rest is accounted for by domestic appliances (fridges and freezers, washing machines, dishwashers and tumble driers, televisions, videos and many more), excluding cases where electrical heating is used. Even though technology is rapidly advancing and appliances are more energy efficient, the electricity consumption associated with their use is rising due to the greater ownership and the fact that more are left on stand-by mode (not fully shut down when not used) or have higher energy demand appliances like plasma TVs which use more electricity. In Australia (Department of the Environment, Water, Heritage and the Arts Commonwealth of Australia, 2008), the percentage of electricity spent on appliances increased from 24% in 1990 to 32% in 2007. In Europe, the energy label on appliances, such as refrigerators, freezers, washing machines shows the appliance’s yearly energy consumption and the energy class. ‘A’ indicates low energy consumption, while ‘G’ indicates extremely high consumption. Using the energy labelling system, a reasonable estimation of the total energy consumption can be determined for that particular appliance. An A-rated appliance will use approximately half as much electricity as a G-rated appliance.

All low energy cost measures have a financial cost, which can represent a barrier in bringing the building to a more energy efficient status. For example, in 1996 Germany introduced preferential loans to finance energy efficiency and refurbishment; these were sustained by public subvention. This could be a solution for each country in order to achieve the energy efficiency through buildings and reduce CO₂ emissions.

Globally there are many different building standards used in practice. In recent years Europe has seen an increasing number of buildings designed to the ‘PassivHaus’ standard. PassivHaus buildings have the following properties: ultra low energy consumption, superinsulated, minimal thermal bridges, exceptional airtightness, with controlled ventilation, providing comfortable indoor climate all year without a conventional heating system for cold months. Consequently renewable energy sources can be used more cost effectively to meet the resulting energy demand. The standards are also applied to refurbishment projects. In Germany over €1 billion of public money per year is being invested in a comprehensive programme for low energy and PassivHaus Standard building refurbishment.

PassivHaus refurbishment projects include the following example which was awarded the Austrian State Award for Architecture and Sustainability. A 1950s five-storey apartment block in Linz, Austria, had the first to fourth storeys of the building refurbished over a six-month period to the PassivHaus standard. The work also included insulating the building’s cellar and the attic. The balconies of the apartments were closed-in during the refurbishment and the glazing was replaced with high efficiency triple-glazed units with integrated solar protection to prevent summer overheating. The refurbishment resulted in a 90% reduction in the monthly heating cost for a 59 m² flat, from €40 to €4 per month (based on an estimated energy price of €0.06 per kWh), and an 89% reduction in CO₂ emissions for the whole building, from 160 tonnes per year to 18 tonnes per year.

The ‘House of the Future’ initiative by the Austrian Federal Ministry for Transport, Innovation and Technology (BMVIT) has set up a detailed network for documenting all PassivHaus projects. The network has covered in total 503 (July 2006) PassivHaus building projects, primarily from Austria, and 40 international projects have also been documented. The network also identifies the importance of the refurbishment projects undertaken on old buildings to the PassivHaus standard. According to forecasts PassivHaus refurbishment projects could contribute to reductions in CO₂ by as much as 3.02 million tonnes (see Fig. 26.9) (IG Passivhaus Austria, 2009).

Future trends in the refurbishment of buildings to reduce energy consumption will look at ways to increase efficiency and performance whilst at the same time reducing the cost of the retrofit technology and the inconvenience to the building’s occupants through quick and easy installations. As costs reduce, the use of high performance insulations which incorporate aerogel and vacuum technologies are likely to become more prevalent due to their ability to provide high thermal resistance. Their highly insulating properties mean that retrofit insulation can be applied internally (or externally) to a building without considerably increasing the overall thickness of the external fabric of a building. This is especially beneficial when looking at applying internal wall insulation. If it is possible to use thinner material with the same insulation properties as a thicker alternative, the former solution will have less impact on the internal spaces.

The implementation of the measures outlined here can help bring about significant theoretical reductions in the energy associated with the world’s existing building stock. However, to ensure that the measures have actually succeeded, it is important that the energy performance of refurbished buildings is monitored to ensure that the design and refurbishment aspirations are actually met.

26.4 Post-occupancy evaluation (POE)

Various definitions and interpretations of post-occupancy evaluation (POE) have been proposed. Preiser et al. (1988) define post-occupancy evaluation (POE) as a ‘process of evaluating buildings in a systematic and rigorous manner after they have been built and occupied for some time’. The Royal Institute of British Architects (RIBA) Research Steering Group (1991) defined post-occupancy evaluation as a ‘systematic study of buildings in use to provide architects with information about the performance of their design and building owners and users with guidelines to achieve the best out of what they already have’. Post-occupancy evaluation is defined in Zimring and Reizenstein (1980) as ‘examinations of the effectiveness for human users of occupied design environments’ – this study focused on the needs of the occupants.

Over time POE has progressed from a one-dimensional feedback process to a multidimensional process. The first evaluations focused primarily on the performance of buildings, while the latest studies emphasise a holistic, process-oriented approach taking into account the political, economic and social aspects. It was demonstrated that in order to assess and improve the thermal performance of buildings, the metered data from POE studies is a suitable method for an initial check (Sawyer et al., 2008).

Different approaches can be considered in a POE study: collecting energy usage data, temperatures, lighting levels, acoustic performance, assessing the occupants using questionnaires, rating the aspects of living comfort in a building, survey data determining the designers’ intentions, occupant comfort and satisfaction, as well as different interpretations from different points of view that could arise. An architect could use the POE study as a part of the design process by making use of the data to improve upon future designs, or even for the modification of existing spaces or performance enhancement.

Improving the energy efficiency of buildings by implementing technologies that reduce carbon emissions can also potentially improve the comfort of the occupants, another aspect that can be ascertained through POE studies. However, more research must be done to determine the impact of the space usage and design on the human behaviour by analysing occupant satisfaction and perception. In order to ensure that there is significant progress towards energy efficiency in the building type that is responsible for the largest proportion of energy consumption, it is necessary to identify the benefits of POE for housing. Such a study could help in taking the right decision in retrofitting an old house, reducing client’s future costs, increasing occupants’ satisfaction whilst at the same time increasing energy efficiency. Refurbishment measures should also maximise the value of the property and minimise maintenance costs. These are other aspects that can be assessed through an effective POE study.

An effective choice of POE methods and strategy should be considered when a POE study is performed. This includes pre-visit questionnaires, semi-structured interviews with the occupants, field observations during walk-through visits, physical monitoring, and experimental tests of building performance. Such a case study is underway (at the time of writing) at the University of Nottingham, where a three-bedroom semi-detached 1930s house, a common typology of home within the UK’s 25 million existing dwellings, is subject to an extensive POE study during a three-year incremental refurbishment programme (Fig. 26.10).

The house is part of the Creative Energy Homes (CEH) Project, University of Nottingham (Fig. 26.11). CEH is a research and educational showcase of seven low or zero carbon houses. It is called the E.ON 2016 Research House due to the UK Government’s commitment for all new housing to be zero carbon by the year 2016. The project will investigate how the same challenge can be applied to existing homes in the most cost effective and efficient way. The project is a collaboration between researchers at the University of Nottingham’s School of the Built Environment and the energy company E.ON.

The key factor driving the project is that in the UK for domestic buildings alone, the energy used for heating, lighting and power in homes produces over a quarter of the UK’s CO₂ emissions. The average household produces about 6 tonnes of CO₂ every year (CLG, 2008). Table 26.2 shows the average CO₂ emissions per dwelling per year for the large UK cities.

There is an urgent need for affordable routes for existing home owners to reduce their energy consumption and adapt their properties to meet sustainable contemporary lifestyles. The project will explore the options for converting a typical 1930s house to a 2016 zero carbon standard. Phase 1 (year 1) is a 1930s scenario: monitor the performance of the house constructed to the 1930s standards – single glazing, no insulation, no draughtproofing and a low efficiency heating system. The second phase (year 2) involves upgrading the house to make it 25% more energy efficient than current UK Building Regulations. The main objective is also to ensure the targets are realistic for the general homeowner achieving a cost-effective standard. In phase 3 (year 3) the house will be further improved to achieve a zero-carbon status. A zero-carbon home is defined as one where net CO₂ emissions resulting from all energy used in the building are zero or better (CLG, 2009).

In the 1930s, cavity walls had only just been introduced, and the wall of the E.ON house comprises a brick outer skin with a 50 mm air cavity and dense concrete blockwork inner leaf which has been plastered internally. The house is only one of a pair of semi-detached homes. Therefore an additional super-insulated timber structure adjoins the house to simulate the house next door thus taking into account any potential for heat loss through what should be the party wall. A research laboratory where the POE monitoring takes place is situated in this timber framed structure and in the loft space above the home.

The house is occupied by a family and is fully monitored. The quantitative data (collected by more than 100 sensors that are monitoring indoor/outdoor climate and energy consumption) is being logged alongside the qualitative data, behaviour/actions of the occupants (i.e. what do the inhabitants do to make themselves comfortable and how do they use the spaces). The environmental monitoring is measured through a network of temperature (placed on the north, south, east, west wall, floor and ceiling of each room), humidity and indoor air quality sensors within the house (Fig. 26.12).

Electricity use is monitored using whole house, circuit and appliance meters. Figure 26.13 shows the individual power circuit monitoring equipment installed in the electricity distribution board of the house. The highlighted area in Fig. 26.13(b) shows current transducers which pick up the current from the magnetic field produced when current flows through the individual circuit cables. The system provides disaggregated power data showing not only how much energy is consumed but where and when it is used. This is extremely valuable information to support decisions such as where and how to make energy savings.

The occupancy patterns and space use are analysed using a real-time and location tracking system (supplied by UBISENSE) which uses ultra wideband radio frequency technology. This is the first time that this technology and system has been used to log occupancy patterns in domestic buildings. The sensors are located strategically in the house so that when a person moves, the system is able to detect the worn tag to within a relatively high accuracy (approximately 15 cm) in three dimensions. Figure 26.14 illustrates the virtual environment of the E.ON 2016 Research House. Software has been developed by Spataru to correlate energy and occupancy data from all the sensors in the house. This enables researchers to look at individual impacts and behaviour patterns which affect energy consumption.

During the project different technologies will be tested: air source heat pumps, different types of insulation (e.g. vacuum insulation panels and vacuum glazing). The key elements of the project are to minimise fabric and ventilation heat losses from the building and to reduce energy requirements for lights and appliances. The purpose of this study is to identify the most cost effective solutions, assess the impact on occupants, inform future stock investment and contribute to best practice.

During the study a series of interviews will be conducted with the occupants. These interviews will help to gauge which measures were seen to be effective and how they impacted on their time spent in the house. The relationships between occupancy and energy usage will also be evaluated and the building performance and energy efficiency diagnosed. In parallel with this, a series of experiments will be performed in the house to allow the testing of different aspects including thermal performance and air leakage testing. The POE study consists of monitoring and managing data collection and analysing data in order to predict the building performance over a period of time and after different stages of refurbishment. The data is analysed in order to report findings, recommendations and review the outcomes. An important aspect of POE is the efficiency of space allocation and space usage. This phase of the project will inform the final phase. The final phase is the most important because it must utilise the identified solutions to solve the problems and make recommendations. The POE study can help determine how well a new concept works once applied.

The thermal images taken in the winter of 2008 (phase 1) are shown in Fig. 26.15. The noticeably brighter parts of the image indicate areas of high heat loss, in particular the single glazed windows, the chimneys and the roof (especially under the eaves).

Besides the building performance, the behaviour of the occupants is increasingly important, because in domestic buildings the occupants exert complete control over the lights and appliances in addition to the heating system, whereas in an office environment there may be restrictions and rules put in place in order to reduce energy consumption. The occupants’ behaviour in using energy can be influenced by the following factors: the number of occupants, age and sex of the occupants, the time spent in the house by each occupant in a dwelling, frequency of shower and bath use, the heating and ventilation preferences of the occupants, income and interest in energy use, comfort, costs and impact on the environment.

Energy and resource waste is still significant, particularly in affluent societies, where energy costs represent only a relatively small share of total living expenses. The main problem is often human behaviour, leaving the lights on in unoccupied rooms, overheating the space or leaving the heating on while the house is unoccupied, boiling more water than necessary in the kettle, leaving machines (such as televisions, computers) on stand-by, leaving electrical chargers plugged in, etc. The energy consumption from some of the habits above, such as leaving machines on stand-by, could appear inconsequential; however the combined energy consumption could contribute considerably to the annual electricity cost. Boardman (2007) concluded that ‘behavioural change will be a vital component, whether from the different professions and trades involved, or from the occupants’.

One solution is new technologies, such as portable products with wireless communications and maybe in the future with wireless power, which can power down energy consumption even when in stand-by mode. Another solution is to make the occupants pay more attention to energy efficiency by providing them with complete information about wasting energy and energy savings. Smart monitors or meters can be used to make occupants aware of how much energy their household appliances consume.

In the UK, for example, because some industrial organisations had to identify solutions to cut costs on their energy bills, a few measures were applied:

On the other hand, in domestic buildings, the occupants control the appliances and may not have enough knowledge about the effect of energy inefficiency, and perhaps they are not concerned by their own impact on the environment. Education and information from POE energy surveys could help improve the attitude of a significant number of households.

26.5 Sources of further information

European projects related to the Energy Performance of Buildings Directive

The most important studies along with their results are found on the internet:

26.6 Acknowledgements

The authors wish to acknowledge E.ON (UK), sponsors of the E.ON 2016 Research House & EPSRC/E.on sponsors of the calebre research project.

26.7 References and further reading