Achieving a holistic view of the life cycle performance of existing dwellings

Abstract

Models which fully evaluate the life cycle energy and greenhouse gas (GHG) emissions of national housing stocks are not reported in literature. Capturing a holistic view of energy and emissions of the residential sector is an important process that can lead to a more effective policy making. This paper presents a methodology which evaluates the life cycle energy and GHG emissions of retrofitting housing stocks considering all life cycle stages and incorporating, to the greatest extent possible, all upstream inputs.To achieve this, we developed a hybrid model of the existing Irish housing stock, comprising a process-based approach supplemented by input -output LCA for installation of materials and fit-outs and maintenance of appliances. Life cycle analysis (LCA) is a commonly accepted technique for evaluating cradle-to-grave environmental impacts of a product. Using an assumed 50-year life span in all cases, representative archetypes were used to estimate the performance along retrofitting, operation, maintenance and disassembly phases of the three selected house retrofit scenarios: BaseCase (no intervention), Current Standards (retrofitting to meet existing building regulations) and Passive House (retrofitting to meet Passive House Standards).Results show that detached houses displayed the highest range of life cycle energy and exhibited the greatest absolute and percentage reductions compared to other house types, as life cycle energy ranges from 386 -614kWh/m 2 .yr, 225 -261kWh/m 2 .yr and 126 -137kWh/m 2 .yr for all house scenarios, respectively. Using these results an assessment is provided for policy makers on a holistic view of the life cycle performance of existing dwellings.

Simplified structural design and LCA of reinforced concrete beams strengthening techniques

“…In this paper, solutions are evaluated according to the Cumulative Energy Demand (CED) v.1.08 indicator (in MJ-Eq or kWh-Eq) and the Global Warming Potential (GWP) indicator, based on 2007 IPCC v1.02 methodology, and using the software tool SimaPro v7.3. These indicators are chosen because these are among the most widely used [23], as in [24,25]. Moreover, they are the first indicators suggested by the standards developed by CEN/TC 350 on the sustainability of construction works in the categories of i) Indicators describing environmental impacts, and ii) Indicators describing resources use.…”

A methodology to assess energy-demand savings and cost effectiveness of retrofitting in existing Swedish residential buildings

“…First, the archetypes and the representative housing stock were developed and selected, which give "as-built" status (Base Case) before retrofitting. The as-built archetype is defined as a significant category of houses, which can be extrapolated to the total energy saving potentials by the numbers of present archetypes from cities or national level (Famuyibo, Duffy, & Strachan, 2013). In the study, archetypes are classified by construction materials, the occupancies and the building ages.…”

Life cycle assessment of energy retrofit strategies for an existing residential building in Turkey

“…Two functional units were considered. A hybrid model for assessing the life cycle energy and GHG emission impacts of retrofitting residential building stocks comprising a process based approach was presented in the study of Famuyibo et al (Famuyibo, A.A., Duffy, A., Strachan, P., 2013). In order to estimate the performance along retrofitting, operational, maintenance and disassembly stages of the three selected house retrofit scenarios, the representative archetypes were used.…”