Environmental and economic optimization and prioritization tool-kit for residential building renovation strategies with life cycle approach

With the continuous development of the global economy, carbon dioxide and other greenhouse gas emissions are persistently increasing, making global warming an indisputable fact. As a high-energy consuming industry, the building industry has gradually emerged as the primary source of greenhouse gas emissions during urban expansion. Consequently, countries are exploring sustainable development pathways for low-carbon buildings to minimize the detrimental impact caused by the construction industry. This paper summarizes the current status of low-carbon building development and, through literature analysis concerning carbon standard systems and carbon emission accountings, discusses the challenges and possible improvements for the future. Establishing a quantitative evaluation tool for carbon emissions and elucidating accounting methods in the construction field is fundamental and a prerequisite for comprehensively studying low-carbon buildings throughout their life cycle. The challenges of low-carbon building development are as follows: (1) lack of a set of carbon emission measurement standards that can be commonly used internationally, (2) lack of a deep and systematic study of the theory of carbon emission accountings and (3) difficulty in recognizing carbon emission boundaries and related data for existing carbon emission accounting methods. This paper provides a comprehensive analysis of the current progress in low-carbon building development, along with an examination and optimization of the application of carbon emission accounting methodologies within construction to address the challenges.

Section: The Life Cycle Assessmentmentioning

confidence: 99%

A Review of Building Carbon Emission Accounting Methods under Low-Carbon Building Background

Xiong,

Wang,

Mao

et al. 2024

“…However, the Swedish Environmental Objectives Committee (Miljömålsberedningen) has officially endorsed the life cycle perspective as a foundational approach for assessing the environmental impact of new construction, rebuilding, and the management of existing buildings, including construction work [33]. Life cycle analysis (LCA) has played a central role in various studies concerning the renovation of residential buildings [28,30,[34][35][36][37][38]. In the case of the renovation project under analysis in this study, researchers closely followed the project from its beginning, employing different assessments to select renovation measures through simulation software [39][40][41][42].…”

Section: Introductionmentioning

confidence: 99%

Greenhouse Gas Payback Time of Different HVAC Systems in the Renovation of Nordic District-Heated Multifamily Buildings Considering Future Energy Production Scenarios

Khadra,

Akander,

Myhren

2024

The European Union (EU) has implemented several policies to enhance energy efficiency. Among these policies is the objective of achieving energy-efficient renovations in at least 3% of EU buildings annually. The primary aim of this study was to offer a precise environmental comparison among four similar district-heated multifamily buildings that have undergone identical energy efficiency measures. The key distinguishing factor among them lies in the HVAC systems installed. The chosen systems were as follows: (1) exhaust ventilation with air pressure control; (2) mechanical ventilation with heat recovery; (3) exhaust ventilation with an exhaust air heat pump; and (4) exhaust ventilation with an exhaust air heat pump with a Photovoltaic (PV) panel. This study involved a life cycle assessment that relied on actual material data from the housing company and energy consumption measurements. This study covered a period of 50 years for thorough analysis. A sensitivity analysis was also conducted to account for various future scenarios of energy production. The findings revealed that the building with an exhaust air heat pump exhibited the lowest greenhouse gas emissions and the shortest carbon payback period (GBPT), needing only around 7 years. In contrast, the building with exhaust ventilation without heat recovery showed the highest emissions and the longest carbon payback period (GBPT), requiring approximately 11 years. Notably, the results were significantly influenced by future scenarios of energy production, emphasizing the crucial role of emission factors in determining the environmental performance of distinct renovation scenarios.

“…Currently, in Europe, the renovation of apartment buildings mostly focuses on the thermal insulation of the building envelopes and on the increasing levels of airtightness, which is commonly carried out by replacing existing windows, with a limited focus on the ventilation of the building after the airtightness increases and on the replacement of the equipment for heating, domestic hot water (DHW), and cooling [5][6][7][8]. This practice leads to superficial (with primary energy savings of up to 30%) and, occasionally, moderate renovations (with primary energy savings between 30% and 60%).…”

Section: Introductionmentioning

confidence: 99%

“…Arbulu et al [7] developed a toolkit for residential building renovations using a lifecycle approach, which considers the integration of passive, active, and renewable energy source (RES) solutions. High importance was given to the passive solutions (thermal insulation), and limited focus was on the active and RES solutions, without any mention of natural or mechanical ventilation within the renovation process.…”

Section: Introductionmentioning

confidence: 99%

Analysis of Measured CO2 Levels through Long-Term Monitoring in Renovated Multifamily Buildings: A Common Case

Măgurean,

Petran

2023

The purpose of this study was to analyze the indoor air quality, in particular, the CO2 level, in a real environment, within 16 apartments located in the municipality of Zalău, Romania, in five recently renovated multifamily buildings in which families live under normal conditions. Long-term monitoring was undertaken for 4.5 months, during the heating season of 2022–2023. A representative microclimate perspective was analyzed: the median value of the time fraction, which exceeded the Indoor Environment Quality Category I (IEQcat I) threshold for adults’ bedrooms was 82.30%. For children’s bedrooms, it was 75.65%, while for living rooms, it was 58.78%. When considering IEQcat IV, it was identified that for the bedrooms, the time fraction for which the threshold values were exceeded was still significant (median value of 45.37% for adults’ bedrooms and 50.14% for children’s bedrooms). Even if the indoor thermal comfort conditions increased, it was found that for almost half of the time, the bedrooms did not provide a health-safe indoor environment for the occupants due to inadequate ventilation, exceeding the health threshold values. Thus, it was identified that the ventilation of buildings is a key issue within the renovation process and, currently, is not properly undertaken for the mass renovation of existing multifamily residential buildings.