Energy Performance Of Building Stock Research Articles

Assessing the impacts of urban morphology factors on the energy performance for building stocks based on a novel automatic generation framework

The building sector accounts for an increasing amount of energy and emissions with continued urbanization, and improving the energy performance of building stocks at the early planning stage is cost-efficient and easy to operate. This study presents an automatic generation framework to quantify the impacts of urban morphology factors on the energy performance of neighborhood-scale building stocks. The typical office building shape is firstly determined by a field survey and clustering analysis. Then the building modular cells-based method is introduced to establish a comprehensive energy performance database for building stocks. The impacts of urban morphology factors on energy performance are further prioritized via global sensitivity analysis. A case study in Shanghai, China demonstrated the proposed automatic generation framework which can act as a generalized paradigm to model building stocks and be widely applicable to other climate zones. The urban morphology factors representing buildings’ geometric characteristics tend to have greater impacts on energy performance, among which the top influencing factors are relative compactness, building coverage ratio, and building height distribution. The proposed framework and the findings are expected to generate valuable insights into energy-efficient urban design.

Improving the Energy Efficiency of an Existing Building by Dynamic Numerical Simulation

Nowadays, the enhancement of the existing building stock energy performance is a priority. To promote building energy renovation, the European Committee asks Member States to define retrofit strategies, finding cost-effective solutions. This research aims to investigate the relationship between the initial characteristics of an existing residential buildings and different types of retrofit solutions in terms of final/primary energy consumption and CO2 emissions. A multi-objective optimization has been carried out using experimental data in DesignBuilder dynamic simulation tool.

Methodology for integrated modelling and impact assessment of city energy system scenarios

Cities are ought to play a key role in the energy transition to a low carbon society as they concentrate more than half of the world's population and are responsible for about 67% primary energy consumption and around 70% of the energy-related CO2 emissions. To achieve the agreed climate targets, efficient urban planning is a must. Tools and methods have risen to model different aspects of the energy performance of urban areas. Nevertheless, addressing the complexity of a city energy system is a great challenge and new integrated tools and methods are still needed. This paper presents a methodology for integrated city energy modelling and assessment, from the characterization of the city's current energy performance to the development and assessment of future scenarios. Energy characterization is based on the combination of bottom-up approaches with top-down data to establish the city's energy baseline. This baseline integrates bottom-up results from a GIS based model which is used to characterize the city's building stock energy performance, while available information on the vehicle stock is used to model the mobility sector. Scenarios are developed from this baseline and assessed through a multi-criteria impact assessment model. A simplified case study is carried out for the city of Valencia (Spain) to demonstrate the suggested methodology, and results are shown for three different scenarios: one focused on the building sector, one on transport, and one combining measures in both sectors. The transport-focused scenario demonstrates to be the most favourable in terms of energy savings and emissions reductions. The application of the proposed method is intended to support the development of strategies and plans for energy transition at city level. The main challenges for its application in cities are data availability at urban level, the uncertainty related to modelling the transport sector, and the unavailability of adapted I/O tables at city scale to assess socioeconomic impacts.

Improving policy making and strategic planning competencies of public authorities in the energy management of municipal public buildings: The PrioritEE toolbox and its application in five mediterranean areas

Making public buildings smarter and more energy efficient requires tailored solutions to overcome the barriers in implementing suitable technology options in a large variety of building types. The PrioritEE project aimed to strengthen the policy-making and strategic planning competencies of local and regional public authorities in the energy management of Municipal Public Buildings, gaining experience in five local pilots in the Mediterranean area. This paper focuses on the PrioritEE toolbox, describing both the “soft components” and the technical components. These components are widely applicable and replicable in all European cities for supporting local administrations in improving energy efficiency and the use of renewable energy sources in municipal public buildings. The Energy Technologies and Building Retrofit Database is a technology repository of energy efficiency measures and renewable energy technologies, providing the main reference data on costs, technical performance and lifetime. With the Decision Support Tool users can assess current building stock energy performance, evaluate different efficiency and renewable interventions, and compare, rank, and prioritize technical options through a set of key performance indicators. A sample of the results to date in the five partner regions are also presented, comparing the main individual characteristics in order to derive replicable solutions for local authorities. This project also highlighted how crucial stakeholder involvement is for tool improvement, capacity building and enabling knowledge transfer.

Assessment of building energy modelling studies to meet the requirements of the new Energy Performance of Buildings Directive

The cost optimal method (COM) as applied in the Energy Performance of Buildings Directive (EPBD) uses “non-calibrated deterministic reference buildings (RBs)”. Such RBs are defined with single envelope and equipment parameter values, for which calibration with actual building stock energy performance (EP) is not undertaken. Thus, it is not possible to visualise the effect of uncertainties or diversity in the input parameters on cost-optimal level benchmarks and to verify the choice of RBs. The paper proposes an update to the COM via use of “Probabilistic Bayesian calibrated RBs” to handle uncertainties and produce more realistic cost optimal levels to support policy makers in devising effective fiscal and legal support mechanisms while facilitating harmonised EP benchmarking between MS for different building categories. The process is validated by findings from Urban Building Energy Modelling studies showing that Energy Use Intensity (EUI) distributions from “probabilistic Bayesian calibrated RBs” versus “deterministic RBs” match significantly closer to the measured EUI distributions with a resulting reduction in the Kolmogorov–Smirnov (KS) test results of up to 82% when monthly calibration was performed.

Criteria and structure of a harmonised data collection for NZEBs retrofit buildings in Europe

The improvement of building stock energy performance is one of the main challenges that Europe is facing. European policies are focused on reducing energy consumption in buildings to achieve the EU 2020 and 2030 goals. One of the greatest opportunities to decrease energy consumption and increase renewable production is represented by nearly zero energy buildings (NZEBs). The European Energy Efficiency Platform (E3P) is an instrument to promote energy efficiency consisting of an online platform to collect and share data and knowledge on energy efficiency topics at EU level. The importance of this tool is in the provision of a harmonised NZEBs database at EU level that can furnish a comprehensive reference guideline about NZEBs retrofit. The database collects retrofit projects implemented in both residential and non-residential buildings. The aim is to record NZEBs projects in Member States and provide an overview of the European status on retrofit buildings. This paper describes the structure of the different sections of the database as well the criteria chosen to implement the data collection at EU level. After an overview of EU energy policies and NZEBs retrofit definitions, a comparison with other available databases is given highlighting pro and cons of alternative data sets mainly characterised by a different focus and level of detail. The paper includes NZEB refurbishment case studies with variable building typologies, measures and climatic conditions, which have a relevant impact on construction technologies and energy needs. The connection with and evolution from the previous data collection tool on Green Buildings towards NZEBs retrofit is also summarised. This database will provide a useful vademecum for stakeholders, researchers, policymakers, designers and building industries that can be inspired from best cases and good practices. The data collected support good practices and information on building energy performance, interventions, savings and costs.This dataset represents a user-friendly open accessible tool to tackle the NZEBs retrofit progress in Member States.

Refurbishment trends of the residential building stock: Analysis of a regional pilot case in Italy

The article illustrates the Italian pilot action in the IEE-EPISCOPE project, focussing on the analysis of energy refurbishment trends of the Piedmont region residential building stock.The methodology follows three steps: (1) definition of a knowledge-base on the current state of the building stock, (2) investigation of refurbishment scenarios considering energy efficiency measures and retrofit rates, and (3) comparison of the achievable CO2 reductions with the climate protection targets in short and middle term. The results are addressed to local authorities to enable them to set up corrective actions to achieve the targets.Three realistic scenarios are investigated. The first one considers the annual current refurbishment trend and the most common energy efficiency measures. The second scenario applies the measures resulting from a cost-optimal analysis. The third scenario considers the mean annual refurbished floor area necessary to meet the climate protection targets. The results of the scenario analyses emphasise the need of implementing major refurbishments, rather than fixing stricter requirements.The building stock energy performance is assessed through the building typology approach defined in the IEE-TABULA project. It allows the models of building stock energy refurbishment to be presented in an effective way, easily understandable and manageable by non-energy experts.

Impact study of the climate change on the energy performance of the building stock in Stockholm considering four climate uncertainties

This work describes the research conducted in order to assess possible changes and uncertainties in future energy performance of the residential building stock in Stockholm. The investigation is performed on a sample of 153 existing and statistically selected buildings and covers the period of 1961–2100. Four uncertainty factors of the climate have been considered: global climate models, regional climate models, emissions scenarios and initial conditions; thereby, 12 different scenarios have been created. Energy performance of the building stock is studied by looking at the overall heating and cooling demand and the indoor temperature. Three cooling strategies of the building stock were evaluated: natural, natural and mechanical (hybrid mode) and only mechanical. To decrease the number of simulations, a method for sampling the climate data has been developed and tested against Sobol quasi-random sampling method.Results of the investigation show that for all the climate scenarios the future heating demand will decrease at the end of the studied period, i.e. around 30kWh/m2 (30%) lower than before 2011, while the cooling demand will increase. Results for the heating demand can differ for about 30% between the scenarios and even more for the cooling demand. Since the current and future cooling demands are rather low, the natural cooling can be the safe choice for mitigating overheating. Uncertainties of the climate data can affect the energy simulation results, but it is possible to rank them and introduce margins to the design based on the importance of the uncertainty factor.

Performance evaluation of non-conventional constructions: Case study in a temperate climate

The development of new construction solutions is fundamental to enhance the building stock energy performance, and thus promote sustainable development in the building sector. These solutions must be sensitive to both the energy performance and the environmental performance. The aim of the work presented in this paper is the energy performance evaluation of non-conventional envelope solutions that were applied in a test building built at the University of Minho's Azurém campus. The evaluation was carried out by means of data analysis of in situ measurements, and also the use of energy and daylighting simulation tools. Prior to the simulations it was necessary to calibrate the model and create a climatic data file representative of the real weather conditions. From this evaluation it was possible to assess the potentialities of different construction solutions. The non-conventional solution presented a similar energy performance but a better environmental performance than the conventional solution, due to the use of lower embodied energy materials. It was also proved that, with minor modifications, the non-conventional solution can produce a better energy performance than the conventional one, evidencing the potential of application of these solutions. ► Test buildings to assess non-conventional construction solutions. ► Energy performance evaluated by measured data and dynamic simulation tool. ► Daylighting performance evaluated by simulation tool. ► Detailed measured data to create weather file and simulation model calibration. ► Non-conventional construction solutions led to a 23% better energy performance.