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The purpose of this study is to identify an objective energy performance assessment method in Korea, and to build a building information modelling (BIM) based system that can assess the energy performance of buildings.

The energy performance assessment methods currently used in Korea were first identified via a literature review. A system was then implemented to solve the problem of objectivity. The system was implemented through a data‐based building information model, instead of the existing method of documented two‐dimensional (2D) CAD. In addition, Revit Architecture (a BIM tool), MS Access, and Visual Basic (VB) were used to implement the system. To verify the system's efficiency, it was compared to the existing method by applying both to an actual case (a school facility).

This study found that the issue of subjectivity in the Korean energy performance assessment method may be resolved with a data‐based BIM.

This study presented the BIM‐EPAS to reduce errors and the time needed to conduct an energy performance assessment. In order to follow a realistic approach, the BIM‐EPAS was applied to an actual assessment case, thereby verifying the system's applicability.

Buildings contribute significantly to CO₂ production. They are also subject to considerable taxation based on value. Analysis shows that while similar attributes contribute to both value and CO₂ production, there is only a loose relationship between the two. If we wish to use taxation to affect policy change (drive energy efficiency behaviour), we are unlikely to achieve this using only the current tax base (value), or by increasing the tax take off this current tax base (unlike extra taxation of cigarettes to discourage smoking, for example). Taxation of buildings on the basis of energy efficiency is hampered by the lack of current evidence of performance. This paper aims to model the now-obligatory (at sale or letting) energy performance certificate (EPC) data to derive an acceptable appraisal model (marked to market, being the EPC scores) and deploys this to the entire population of properties. This provides an alternative tax base with which to model the effects of a tax base switch to energy efficiency and to understand the tax incidence effects of such a policy.

The research uses a multiplicative hedonic approach to model energy efficiency utilising EPC holding properties in a UK jurisdiction [Northern Ireland (NI)] as the sample. This model is then used to estimate discrete energy assessments for each property in the wider population, using attributes held in the domestic rating (property tax) database for NI (700,000+ properties). This produces a robust estimate of the EPC for every property in its current condition and its cost-effective improved condition. This energy assessment based tax base is further used to estimate a new millage rate and property tax bill (green property tax) which is compared against the existing property tax based on value to allow tax incidence changes to be analysed.

The findings show that such a policy would significantly redistribute the tax burden and would have a variety of expected and some unexpected effects. The results indicate that while assessing the energy performance of houses can be a complex process involving many parameters, much of the explanatory power can be achieved via a relatively small number of input variables, often already held by property tax jurisdictions. This offers the opportunity for useful housing stock modelling – such as the savings possible from power switching. The research also identifies that whilst urban areas display the expected “heat island” effect in terms of energy consumption, urban properties are on average more efficient than suburban/rural properties. This facilitates spatial targeting of policy messages and initiatives.

Analogous with other studies, data deficiencies introduce the risk of omitted variable bias. Modelling of the energy efficiency in the sample is limited to property attributes that are available for the wider population of properties. While this limits the modelling exercise, it is a perennial issue facing mass appraisal worldwide (where knowledge of the transacted sample attributes generally exceeds knowledge of the unsold properties). That said, the research demonstrates the benefits of sharing data and improving knowledge of the housing stock, as taxation databases would be stronger, augmented with EPC-derived property attributes for example.

The EPC lead in time for wide residential coverage is likely to be considerable. The paper contributes to emerging literature and policy debate surrounding the effect, performance measurement and implementation of energy efficiency certification, through a greater understanding of the sectorial and geographical dispersion of energy efficiency. It provides high level research to help guide policy and decision-making, identifying key locales where there is more of a physical problem and locations where there is more to gain in terms of targeting energy improvement and/or encouraging behavioural change. The paper also allows a glimpse of the implications of a change towards a taxation regime based on energy efficiency, which contributes to the debate surrounding the “greening” of property based taxes.

Building energy performance is a key element when assessing the sustainability, or otherwise, of the built environment. However, the prescriptive nature of current approaches to sustainability assessment stultifies innovative approaches to sustainable building design. The purpose of this paper is to illustrate how a current EU FP7‐funded project, entitled “IntUBE – Intelligent Use of Buildings' Energy Information,” will contribute to improving the measurement and evaluation of building energy performance. The paper also seeks to highlight the potential offered by the energy‐profiling tools and techniques being developed as part of the project to contribute to the assessment of sustainable urban development.

The IntUBE project is developing new methods of integrating the information and communication technologies (ICTs) used in the design and operation of buildings, with the aim of facilitating improvements in the energy performance of buildings and the measurement of that performance. To do so, the project will develop new methods and tools which integrate design phase and operational phase energy profiling.

Integrating the ICTs used to assess the design and operation of buildings could significantly improve the way in which the energy performance of buildings is assessed. However, there are many barriers to the adoption of the energy‐profiling software tools designed for professional use. This is problematic because a more generalised uptake of these tools is essential to improving the measurement and evaluation of building energy performance.

It is important that the energy‐profiling tools and techniques developed within the IntUBE project ameliorate as many of the barriers to the adoption of the energy‐profiling software tools as possible. To do so new approaches to the following are under development; the integration of building information model authoring software and energy simulation software, the integration of simulation and real‐time data‐capturing sensors, and evaluating and selecting amongst the design alternatives offered by energy simulation software.

Pressure is growing globally for larger businesses to improve the energy performance of the buildings in which they operate. Property or facility managers are usually responsible for these improvements through energy‐led refurbishment. The number and complexity of possible interventions pose challenges that these professionals attempt to meet by using decision support tools (DSTs). The work aims to identify key features of DSTs for energy‐led building refurbishment and define an optimum approach.

A desk study examined ten DSTs reported in the available literature and evaluated them against a set of desirable attributes that a property or facility manager would value for this task.

The results of the desk study concluded that no DST offers every feature and that there is an opportunity for a new DST for energy‐led refurbishment. An optimum DST template is proposed, consisting of a seven‐step process from assessment of the existing state of the building through to continuous evaluation and improvement of the refurbished building.

The work combines the best features of available DSTs into a novel optimised strategy for energy‐led refurbishment of non‐domestic buildings, which is geographically non‐specific and could be applied anywhere in the world.

To establish national energy performance benchmarks and an energy efficiency classification system for commercial office buildings from whole building to sub‐systems level for building professionals including facility managers.

Issuing of survey form and questionnaires to 16 building owners before field interview. Building physical data and systems nameplate, quantities and types were verified on site. The past 24 months electricity consumption bills were also collected from building owners. Physical environmental conditions and short‐term power measurement on building systems were done to determine the level of energy consumption and performance.

The classification and benchmarking methodology developed is useful for the regions to establish their own database and tools.

The building energy performance assessment and auditing methodology are useful to both building owner/manager and energy services companies (ESCOs) in carrying out systematic assessment and analysis on building energy characteristics. The benchmark system established will also serve as a reference to building professionals to adopt a more holistic approach in designing an energy efficient building. Useful also for building owners who are considering carrying out retrofitting works on their existing building or systems.

The study provides detailed whole building and systems benchmarks for Singapore. The results provide an objective evaluation system of commercial office building energy performance.

Global warming and climate change is one of the biggest issues facing humanity in this century; its effects are felt on the highest peaks of Mount Everest to the low-lying islands in the India Ocean. This century marked the highest amount of carbon dioxide (CO₂) emitted, breaking records of the past 650,000 years, and we have pushed the climate to “a point of no return”. Much of the climate contribution has been linked to humanity’s thirst for higher living standards and lifestyle, which has led to higher consumerism, depletion of earth’s resources, production of massive waste and carbon emissions. Fast forward from the sustainability agenda of Brundtland set in 1987 and the increasing demand for energy consumption to cater for the current global inhabitants, many “green” efforts have been taken by the building industry to reduce the overall environmental impact. This purpose of this study is to compare energy performance of a conventional office building with a green certified building.

This paper tries to bridge the performance gap by comparing measured operational energy consumption and carbon emission of Green Building Index (GBI)-certified office buildings in Kuala Lumpur, to determine whether “green buildings” are performing as intended in reducing their environmental impact.

This paper highlighted and compared operational energy consumption and carbon emissions of a GBI-certified office with a conventional office building in Malaysia. The paper also discusses the performance gap issue and its common causes, and aims to compare predicted energy and operational energy performance of buildings.

Initiatives such as “green” or “sustainable” design have been at the forefront of architecture, while green assessment tools have been used to predict the energy performance of a building during its operational phase. There is still a significant performance gap between predicted or simulated energy measurements to actual operational energy consumption. The need to measure actual performance of these so-called “green buildings” is important to investigate if there is a performance gap and whether these buildings can perform better than conventional buildings. Understanding why the performance gap occurs is a step in reducing actual and predicted energy performance in buildings.

Decentralized solar systems are increasingly being used as alternative source of off-grid electrification in Bangladesh. They offer solutions to provide (clean) electricity to the low-income households that are not currently served by the national grid. The standards of solar systems need to be improved to maximize the benefits they offer for off-grid electrification.

A quantitative research approach was used to explore the power output performance of six solar systems samples. In order to realize a proper load management, daily power production was measured to determine the generation capacity of 50, 60 and 100 Wp monocrystalline and polycrystalline modules when average solar irradiation was 916 W/m². In the testing system, the irradiation was measured by panel analyzer HT instrument I-V 400. The load arrangement comprised of different kinds of appliances (fan, light, TV). The daily consumption of energy by these loads was calculated using daily operational hours to determine system power performance.

The authors found that monocrystalline system performs better than polycrystalline by 0.39 kilowatt-hour (kWh) with capacity of 100 watt-peak (Wp) modules. The carbon dioxide (CO₂) emissions reduction potential of our sample solar systems were also estimated by assuming a scenario. This was derived by using the electricity emission factor for natural gas (CH₄), since CH₄ is the main source of energy for power generation in Bangladesh. Savings in CO₂ of 0.52 kgCO₂/kWh is possible with the adoption of a 100 Wp monocrystalline module.

Government actions that promote the use of monocrystalline module will enhance the benefits of the use of solar systems in providing quality and sustainable electricity. This will contribute to government's efforts towards achieving some of the United Nations (UN) sustainable development goals (SDG) and resilience of the most vulnerable population to the effects and impacts of climate change.

Almost all solar modules found in off-grid areas are polycrystalline whose energy generation capacity is much lower compared to monocrystalline types. But use of low efficient polycrystalline solar module hindered the development of country's solar sector and option to save carbon emission. The use of highly efficient monocrystalline solar module will save also the country's land as the country has land scarcity challenges for establishing large-scale solar power plant. The authors also recommend actions that can be implemented at the national level to improve the attractiveness of monocrystalline solar systems in Bangladesh.

Electric lighting accounts for a large share of energy consumption in commercial buildings. Utilization of daylight can significantly help to reduce the need for artificial lighting, increase workers productivity, customers’ satisfaction and consequently improve sales. However, excessive use of glazing and absence of lighting controls can contribute greatly to higher energy need for heating and cooling and cause undesired glare effects. Thus, optimizing the size, position and materials of external glazing, with the addition of deflectors and dynamic artificial lighting, can become key aspects in the design of sustainable low energy buildings. The purpose of this paper is to analyze daylight potential and energy performance of a hall-type commercial building, situated in the cold climate of Finland, by utilizing different combinations of skylights, windows and lighting controls.

The authors have used computer simulations to estimate daylight and energy performance of a single floor commercial building in relation to various combinations of skylights and windows with variable glazing materials, light deflectors and zonal lighting controls.

The results show that electric light energy saving potential ranges from a negligible 1.9 percent to a significant 58.6 percent in the case of glass skylights and wall windows using multi-zone lighting control. Total delivered energy ranges between increase of 1.5 and 21.2 percent in the cases with single zone lighting control and between decrease of 4.5 percent and increase of 4.5 percent in the cases with multi-zone control. The highest decrease in primary energy consumption was 2.2 percent for single zone and 17.6 percent for multi-zone lighting control. The research underlines the significant potential of electric light energy savings using daylighting strategies that, including the control of direct solar access for glare and internal gains, can be more than 50 percent.

This research combines accurate daylight and energy assessment for commercial hall buildings based in cold climate region with multiple design variations. The novelty of this work is the consideration of interior elements, shelves and deflectors, in the calculations. This is made possible through the combined use of validated simulation platforms for detailed annual daylighting and electric lighting calculation (Radiance and Daysim) and energy analysis (IDA-ICE, Equa Simulation AB). This method allows to obtain a reliable assessment of the potential of using natural light sources in buildings.

Window shading has always been an effective technique to control the access of solar radiation; however, inappropriate selection of the shading technique, location and optical properties may lead to an increase in energy consumed for cooling and artificial lighting. Venetian blinds (VBs) are a type of adjustable shading devices that can be installed to the interior, exterior or in between glass panes of a window and that can be easily implemented in both new and existing buildings. This study aims to investigate the impact of three VB parameters: slat angle, reflectivity and location on the overall energy consumption of a residential space with a south-facing facade under the hot arid desert climate of Saudi Arabia’s capital, Riyadh. For the purpose of globalizing the findings, the same investigations were applied for two other cities of similar climates: Cairo, Egypt, and Arizona, the USA.

A test room was modelled for energy simulation, with a 20% window-to-wall ratio. A VB was assigned with alternatives of being located to the indoor, outdoor or in between double glass panes. High, medium and low reflectivity values were applied at each location at slat angle alternatives of 15°, 30°, 45°, 60°, 75° and 90°.

Results showed VB performance across slat angles, where up to 20.1% energy savings were achieved by mid-pane high reflectivity VBs in Riyadh, while the value exceeded 30% in case of being externally located. A similar performance pattern occurred in the other two cities of hot arid desert climates: Cairo and Arizona.

The study is limited to VBs at a fixed position, with no upward movement for partial or full openness conditions. The effect of blind control and operation on performance, such as the amount and duration of openness/closure of the blind and changes in slat angle across time, in addition to VB automation, shall be investigated in a future study.

The better understanding of VB energy performance achieved would enhance a more rational selection of VBs, which would benefit the construction industry as it would assist designers, real estate developer companies, as well as end-users in the decision-making process and help to realize energy-efficient solutions in residential buildings. VB production entities would also benefit by manufacturing and promoting for energy-efficient products.

In this study, a matrix of combinations of three VB parameters was developed, and the effect of these combinations on the overall energy consumption of both artificial lighting and heating, ventilation and air conditioning (HVAC) systems was evaluated and compared to identify the combinations of higher efficiency. The literature showed that these three parameters were hardly investigated in a combined form and hardly assessed by considering the overall energy consumed by both artificial lighting and HVAC.

A number of studies have investigated the relationship between energy performance certificates (EPCs) and house prices. A majority of studies have tended to model energy performance pricing effects within a traditional hedonic conditional mean estimate model. There has been limited analysis that has accounted for the relationship between EPCs and the effects across the pricing distribution. Moreover, there has been limited research examining the “standard cost improvements EPC score”, or “potential score”. Therefore, this paper aims to quantify and measure the dynamic effects of EPCs on house prices across the price spectrum and account for standardised cost-effective retrofit improvements.

Existing EPC studies produce one coefficient for the entirety of the pricing distribution, culminating in a single marginal implicit price effect. The approach within this study applies a quantile regression approach to empirically estimate how quantiles of house prices respond differently to unitary changes in the proximal effects of EPCs and structural property characteristics across the conditional distribution of house prices. Using a data set of 1,476 achieved transaction prices, the quantile regression models apply both assessed EPC score and bands and further examine the potential EPC rating for improved energy performance based on an average energy cost improvement.

The findings show that EPCs are valued differently across the quantiles and that conditional quantiles are asymmetrical. Only property prices in the upper quantiles of the price distribution show significant capitalisation effects with energy performance, and only properties with higher EPC scores display positive significant effects at the higher end of the price distribution. There are also brown discount effects evident for lower-rated properties within F- and G-rated EPC properties at the higher end of the pricing distribution. Moreover, the potential energy efficiency rating (score) also shows increased effects with sales prices and appears to minimise any brown discount effects. The findings imply that energy performance is a complex feature that is not easily “averaged” for valuation effect purposes.

While numerous studies have investigated the pricing effects of EPCs, they have tended to provide a single estimate to determine the relationship with price. This paper extends the traditional analytical insights beyond the conditional mean estimate by examining the quantiles of the relationship between EPCs and house prices to enhance the understanding of this esoteric and complex issue. In addition, this research applies the assessed energy efficiency potential to establish whether effective cost improvements enhance the relationship with sales price and capitalisation effects.