Life Cycle Assessment and Service Life Prediction

Abstract

Models of buildings in life cycle assessment (LCA) often use simple descriptions of operational energy, maintenance, and material replacement. The scope of many building LCAs is often limited and uses assumptions such as building lifetimes of 30 to 50 years. In actuality, building lifetimes vary considerably, and scenarios using standard assumptions may have incorrect results. Assumptions concerning material replacement, repair, and maintenance should be deliberate and as realistic as possible. This research was initiated to demonstrate the importance of service life assumptions on building life cycle assessment results. Three roof types (built-up, thermoplastic membrane, and vegetated) and three wall forms (brick, aluminum, and wood siding) were analyzed. These materials were combined and modeled as nine distinct building envelopes. Five service life models were used to determine the service life of materials and systems. The analysis considered impacts related to material manufacturing, construction, operation, and maintenance. The Tool for the Reduction and Assessment of Chemical and other environmental Impacts global warming potential, atmospheric eco-toxicity, and atmospheric acidification impact assessment indicators were used. The analysis of the cumulative life cycle impact and life cycle impact per year found that life cycle impact was primarily dependent on the predicted frequency of major material replacement as well as differences in the frequency and intensity of prescribed maintenance. In some scenarios, the relative differences in the life cycle impact of the alternatives were dependent on the environmental indicator used.Volume 18, Number 2 of the building components. Some have employed protracted study periods of 30 years, based on the rationale that most trends are established at an early juncture, longer building life cycles become increasingly less relevant as time progresses, and results will not change regardless of the study period duration. Such generic assumptions belie the unique characteristics of building materials and assemblies. Whereas maintenance and repair impacts constitute a relatively smaller proportion of a building's or material's cumulative system impact, requirements vary and their omission or inaccurate assumption in the modeling of systems can obscure the results. If indeed the selection of materials

Design and construction strategies for reducing embodied impacts from buildings – Case study analysis

“…Therefore, it should be noted that as a result of the diversity of the methodologies used in the case studies and literature, the individual cases cannot be used to quantify reductions in general, but instead, illustrate the potential of different reduction strategies in various contexts. [42] Light weight construction CZ2, [43] NO4 [44], [39] NO2 [45] Optimising building form and design of lay-out plan SE4 [25] SE3 [28] NO1 [46] Building/service life extension SE7 [26] DK3a,b [47], [48] Element level analyses: [49], [50] JP4 [51] DK1 [52] Reusing building structures No comparative studies, but related Annex 57 case studies include UK12, DK1, SE7, CH1-5, CH8-9, CH11-13, AT4, [53] Flexible/adaptable design DK3c [47] SE6 [54] UK8 [55], UK11 [41], [56] Reducing construction stage impacts UK3, SE7 [26] UK5 [29], [57], [34] UK7 [33] Reducing end-of-life impacts [58] UK7 [33] 3…”

Impact of Service Life on the Environmental Performance of Buildings

“…In addition, the accelerated tests are quite expensive. There are also some other approaches to predict SL by considering service life models and obsolescence factors [1,34]. This method can be used for existing buildings or to be built buildings with the same material.…”

“…Life cycle assessment (LCA) studies that have been conducted, to date, consider the service life of building and building components between 30 and 70 years with a most commonly used value of 50 years (Table 1). However, the real picture is quite contradictory to these assumptions as the service life of buildings varies with materials, operation and maintenance and the surrounding environment [1,2]. This discrepancy may lead to inaccuracy of LCA analyses, and material and energy balance.…”

Cost-Effective Options for the Renovation of an Existing Education Building toward the Nearly Net-Zero Energy Goal—Life-Cycle Cost Analysis

“…Research from the building and construction industry identified eight major factors that influence the cost and schedule of a project (new and renovation) [7,30,31]: Complexity of the building, technological requirements, project information, project team requirements, contract requirements, project duration, market requirements, and site requirements. Among those eight factors, three factors are particularly essential to a renovation project with an aim to achieve net zero: Complexity, technological requirements, and site requirements.…”