Cristina Becchio

Occupant behavior lifestyles in a residential nearly zero energy building: Effect on energy use and thermal comfort

Occupant behavior is one of the most significant driving factors of uncertainty in the prediction of building energy use. Large performance gaps have been individuated between residential buildings with the same properties and similar climate conditions. Comfort criteria settings by the occupants and their interaction with the envelope and the systems directly affect the operation of buildings and related energy uses. This study employs building simulations to demonstrate the potential impact of occupant behavior lifestyles and different household compositions on energy use and thermal comfort conditions in a residential nearly zero energy building under-construction. In detail, occupant behavior was classified into three lifestyles: low consumer, standard consumer, and high consumer. The analysis considered energy-related behavioral patterns (regulation of heating and cooling set-points, energy use for equipment, lighting and domestic hot water, ventilation rates, regulation of window blinds) and highlighted key variables, which need to be addressed by decision-makers of behavioral change programs for conscious use of nearly zero energy buildings. While predictive studies concerning energy performance investigated mainly nearly zero energy building models that addressed the optimization of the building features themselves, this research reveals the urgent need of reference models related to human behavioral issues.

A MCDA-Based Approach for Evaluating Alternative Requalification Strategies for a Net-Zero Energy District (NZED)

In Europe the building sector is responsible for more than 40 % of the total energy consumption and for 36 % of the CO2 emissions. To avoid a further increase of these values, the European Union decided to issue several Directives in order to encourage the reduction of energy consumptions and to promote the use of renewable energy sources. In particular, the recast of the European Energy Performance of Buildings (Directive 2010/31/EU) promotes the improvement of buildings energy performance within the European Union, and introduces a new standard, the nearly-Zero Energy Building (nZEB). More recently, the European Commission is shifting the matter with steady increase from the single level of the building to the district one in order to hit the target of post-carbon cities and the concept of Net-Zero Energy District (NZED) is emerging. The evaluation of alternative strategies for the construction of NZED constitutes a multidimensional problem, where different aspects and impacts have to be considered, from the reduction of pollutant emissions to the investment cost, from the increase in indoor comfort to the creation of benefits in term of real estate assets value. The objective of the present study concerns an investigation of Multicriteria Decision Analysis for supporting decision problems in the context of NZED. In particular, starting from a real case study in the city of Turin (Italy), the multicriteria PROMETHEE method is employed for comparing four alternative strategies for the construction of a new NZED and to select the best solution from a socio-economic and environmental point of view.

Evaluating Health Benefits of Urban Energy Retrofitting: An Application for the City of Turin

The European Union (EU) has committed to lower GHG emissions for a 20% with respect to 1990 by 2020, reaching an 80% reduction by 2050. Renewable energy and buildings retrofitting will be key measures in cutting environmental impacts according to the new climate targets. The development of these energy-efficiency measures requires significant financial resources. The promotion of renewable-energy sources needs public acceptance to facilitate financial support for government. There is a growing body of literature that recognizes how the benefits of applying energy-efficiency measures outweigh the realization costs. Within this context, an evaluation of the whole range of co-impacts is crucial to compare different alternatives with the same objective. To implement a tool to assess the feasibility of a retrofitting project, firstly it is indispensable to identify the various possible benefits in a standardized manner and monetary terms. Secondly, it is fundamental to specify a logical path for assessing the attainment of these benefits, based on the features of the project. Recently, researchers have shown an increased interest in the evaluation of benefits. Despite this interest, very few studies have investigated the impact of the energy improvements of buildings on indoor comfort and human- health conditions. This work contributes to close the data gap in this context, investigating the health benefits connected to retrofitting interventions in residential buildings. A hybrid approach based on Contingent Valuation Method and economic analysis was applied to assess the impacts delivered by the energy retrofitting to an urban district in the city of Turin (Italy). A questionnaire was employed to elicit an estimate of consumers’ Willingness-To-Pay for better indoor comfort conditions and fewer hazards to health, reducing poor building features in terms of energy efficiency and air quality. A bidding game model was created to converge to the expected annual economic value of acceptable comfort conditions in the residential houses.

The Impact of Users’ Lifestyle in Zero-Energy and Emission Buildings: An Application of Cost-Benefit Analysis

The increase in energy exploitation and air pollution have forced the European Union to deal with energy saving and CO2 emissions reduction. With specific reference to buildings, important targets by 2050 have been established, implementing 2020 energy saving goals, and the concept of NZEB (nearly zero energy building) has emerged. In this context, clear understanding of buildings energy performances achieves primary importance and the inclusion of new variables in the analysis such as the user behavior can offer some insights into the solution of the discrepancy between predicted and real energy performances. In the research, an apartment block settled in Turin (Northern Italy) is selected as case study, energy retrofit measures formulated and evaluated including different users’ lifestyles by means of Cost-Benefit Analysis.