Search Results (6)

The paper includes a historical analysis of real energy consumption and indoor conditions in a single-family passive building located in Warsaw, Poland. Passive houses have emerged as a sustainable alternative to the conventional construction of houses, having advantages such as low energy consumption, comfortable indoor temperatures, an environmentally friendly nature, and low carbon emissions. This research consists of indoor temperature assessments over a 5-year period (2018–2022) which include comfort assessments made in accordance with the standard EN 16798-1 and precise assessments made for extreme weather events over a two-week critical period including the heating and cooling seasons. The real energy consumption analysis, including electric heating, outdoor lighting, indoor lighting, ventilation, and domestic hot water, was compared against passive house and nearly-zero energy standards. The results of the study show that the building is thermally comfortable to live in, as it remained mainly in the first comfort category, IEQ I. There was no such issue as overheating and underheating even during extreme weather events. The energy need for heating remained very close to the passive standard, namely 15 kWh/(m²·year). The total primary energy consumption for heating, hot water, and electricity meets the standard required value of 120 kWh/(m²·year). These findings demonstrate the effectiveness of passive house design principles at achieving high levels of thermal comfort and energy efficiency in cold climates. In addition, it is demonstrated that it is possible to maintain comfortable indoor temperatures (even with outdoor air temperatures reaching 35 °C) without air conditioning or cooling systems. The integration of a photovoltaic system offers a viable pathway toward transforming the building into a zero-energy standard, contributing to sustainability goals and reducing carbon emissions. Full article

The need to design buildings in compliance with the Paris Agreement goal requirements is urgent, and architects and engineers need to consider energy use and operational and embodied carbon requirements in doing so. Building envelopes will be an important element in the next generation of high-performance buildings and there have been significant advancements in recent years to develop building envelopes that help mitigate the building carbon emissions through energy-conserving low-embodied carbon or carbon-sequestering solutions. The key objective of this article is to present an overview of the state-of-the-art in the field of energy-efficient low-carbon buildings with a focus on envelope systems. This article provides a survey of the literature on energy use and carbon emissions of the United States building stock, presents recent advancements in energy-conserving building envelopes, and highlights reuse–reduce–sequester strategies that mitigate the embodied carbon of buildings. As materials are critical in reducing the energy consumption and carbon emissions of buildings, this paper also presents developments on diverse materials and building envelope solutions that have been effective in creating high-performance buildings, from insulation materials to phase-change materials and aerogels. Finally, the characteristics of a selected number of progressive net-zero-energy guidelines such as Passive House Institute (PHI) standards, Passive House Institute US (Phius) standards, the PowerHouse standard, and the BENG standard are discussed. The findings of this work highlight the increased focus on the design, construction, and engineering strategies that aim to mitigate the carbon emissions of buildings based on a holistic whole-life carbon mitigation approach. Full article

The UK has one of the least energy-efficient housing stocks in Europe. By 2030, the emissions from UK homes need to fall by at least 24% from 1990 levels to meet the UK’s ambitious goal, which is reaching net-zero emissions. The originality of this paper is to apply the building typology approach to predict energy savings of the UK housing stock under a step-by-step energy retrofit scenario, targeting the Passive House Standard for refurbishments of existing buildings, namely the EnerPHit “Quality-Approved Energy Retrofit with Passive House Components.” The typologies consist of twenty reference buildings, representative of five construction ages and four building sizes. The energy balance of the UK residential buildings was created and validated against statistical data. A building stock retrofit plan specifying the order in which to apply energy efficiency measures was elaborated, and energy savings were calculated. The predicted total energy demand for the UK residential building stock for the year 2022 is 37.7 MTOE, and the carbon emissions estimation is 65.33 MtCO₂e. The energy-saving potential is 87%, and carbon reductions are about 76%, considering all the steps of renovation applied. It has been demonstrated that the step that provides the biggest savings across the housing stock is the one that involves replacing windows, draught-proofing, and installing mechanical ventilation with heat recovery. Full article

While high-rise mass-timber construction is booming worldwide as a more sustainable alternative to mainstream cement and steel, in South America, there are still many gaps to overcome regarding sourcing, design, and environmental performance. The aim of this study was to assess the carbon emission footprint of using mass-timber products to build a mid-rise low-energy residential building in central Chile (CCL). The design presented at a solar decathlon contest in Santiago was assessed through lifecycle analysis (LCA) and compared to an equivalent mainstream concrete building. Greenhouse gas emissions, expressed as global warming potential (GWP), from cradle-to-usage over a 50-year life span, were lower for the timber design, with 131 kg CO₂ eq/m² of floor area (compared to 353 kg CO₂ eq/m²) and a biogenic carbon storage of 447 tons of CO₂ eq/m² based on sustainable forestry practices. From cradle-to-construction, the embodied emissions of the mass-timber building were 42% lower (101 kg CO₂ eq/m²) than those of the equivalent concrete building (167 kg CO₂ eq/m²). The embodied energy of the mass-timber building was 37% higher than that of its equivalent concrete building and its envelope design helped reduce space-conditioning emissions by as much as 83%, from 187 kg CO₂ eq/m² as estimated for the equivalent concrete building to 31 kg CO₂ eq/m² 50-yr. Overall, provided that further efforts are made to address residual energy end-uses and end-of-life waste management options, the use of mass-timber products offers a promising potential in CCL for delivering zero carbon residential multistory buildings. Full article

The Energy Performance of Buildings Directive (EPBD) has introduced the concept of Nearly Zero Energy Buildings (NZEB) specifying that by 31 December 2020 all new buildings must meet the nearly zero- energy standard, the Passive House standard has emerged as a key enabler for the Nearly Zero Energy Building standard. The combination of Passive House with renewables represents a suitable solution to move to low/zero carbon. The hypothesis in this study is that a certified passive house building with high levels of airtightness with a balanced mechanical ventilation with heat recovery (MVHR) should yield lower indoor radon concentrations. This article presents results and analysis of measured radon levels in a total of 97 certified passive house dwellings using CR-39³ alpha track diffusion radon gas detectors. The results support the hypothesis that certified passive house buildings present lower radon levels. A striking observation to emerge from the data shows a difference in radon distribution between upstairs and downstairs when compared against regular housing. The study is a first for Ireland and the United Kingdom and it has relevance to a much wider context with the significant growth of the passive house standard globally. Full article

Two eight-story wood-framed residential buildings with the Swedish 2012 passive house standard were built in 2009 in the Portvakten Söder quarter in the city of Växjö in Sweden. In this paper, we present the monitored specific energy use of the buildings and compare to the requirements of the Swedish building code and recommendation for passive houses. We also estimated the primary energy use and CO₂ emissions and investigated the tenants’ views and experiences of the two buildings. Results show that the actual specific energy use of 40.2 kWh/m²A_temp/year in the Portvakten Söder building fulfills, by a good margin, the requirements of the Swedish building code and the recommended passive house standard, but is higher than projected. Applying a marginal perspective, the calculated primary energy use and carbon dioxide emission from operating the buildings (excluding household electricity) was 40 kWh/m²A_temp/year and zero, respectively. Responses of 20 tenants to a mail-in questionnaire survey showed that over 90% were satisfied with their apartments. Full article