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This paper investigates the possibilities and challenges of using mass timber as a sustainable alternative for retrofitting existing buildings in Canada. To create the knowledge foundation on which to devise a holistic framework tailored to the specific characteristics of Canada's built environment, a detailed analysis of the types, geographical distribution, structural, and energy features of the local building stock is first presented. Then, previous strategies for enhancing and upgrading existing buildings with engineered timber are reviewed, classified, and evaluated. Finally, to explore economic and environmental implications, a detailed assessment of available life-cycle cost–benefit analysis approaches is conducted alongside their adaptation to Canada's building context. The findings of this paper can inform policymakers, builders, and designers in developing more sustainable building retrofit practices, design, and regulations, in line with Canada's efforts toward net zero emissions. [ABSTRACT FROM AUTHOR]

A seismically resilient transportation network entails preprioritized retrofit plans for conventionally designed highway bridges. This is particularly important for the province of Ontario in Canada, where more than 44% of the multispan bridges have been constructed prior to 1970. To support future seismic risk mitigation efforts, this study evaluated the seismic performance of a multispan continuous reinforced concrete bridge in Ontario, Canada, in its as-built and retrofitted conditions. Seismic retrofit is conducted utilizing novel Fiber Reinforced Elastomeric Isolators (FREIs). Analytical fragility curves are developed using Incremental Dynamic Analysis (IDA) on a three-dimensional nonlinear finite element model of the bridge using 45 synthetic ground motion records for eastern Canada. Results indicate that seismic isolation can effectively mitigate the seismic demand on columns and transfer the shear forces to the end abutments resulting in excessive backfill soil deformation. However, this deformation does not necessarily result in bridge failure and traffic disruption. [ABSTRACT FROM AUTHOR]

Assessing the energy performance of existing residential buildings (ERB) has been identified as key to improving building energy efficiency and reducing associated greenhouse gas emissions in Canada. However, identifying optimal retrofit packages requires a significant amount of knowledge of building energy modelling, and it is a time-consuming and laborious process. This paper proposed a data-driven framework that combines machine learning, multi-objective optimization, and multi-criteria decision-making techniques to evaluate the energy performance of ERB and thereby formulate optimal retrofit plans. First, an artificial neural network (ANN) was developed to predict the energy performance of a wide range of retrofit packages. A genetic algorithm was employed to determine the best structure and hyperparameters of the ANN model. Then, the energy consumption results were integrated with environmental and economic impact data to evaluate the environmental and economic performance of retrofit packages and thereby identify Pareto optimal solutions. Finally, a multi-criteria decision-making method was used to select the best retrofit packages among the optimal solutions. The proposed framework was validated using data on a typical residential building in British Columbia, Canada. The results indicated that this framework could effectively predict building energy performance and help decision-makers to make an optimal decision when choosing retrofit packages. [ABSTRACT FROM AUTHOR]

Coupled shear walls (CSW) are an efficient lateral load-resisting system. Their seismic performance depends primarily on their coupling beams (CBs) ability to provide adequate stiffness and strength. However, many existing buildings with CSW resisting system were designed and constructed according to old codes and standards with insufficient requirements for seismic design. These systems feature unsatisfactory behaviour and prematurely collapse in case of major earthquake events. Therefore, their seismic retrofit is urgently needed. The main objectives of this study are, i) evaluate and compare the seismic performance of CSWs designed to old and new codes; ii) highlight the deficiencies of CSWs designed to old codes; iii) investigate a retrofit method using externally bonded (EB) carbon fibre reinforced polymer (CFRP) composites to enhance the seismic response of deficient CSWs. To that end, a 20-story CSW is considered with different design details including one according to old National Building Code of Canada (NBCC) before the 1970s and the other one designed consistent with the new NBCC 2015 and the Canadian Standard Association, CSA A23.3–14, for Eastern seismic Canadian zone. The nonlinear analyses of CSWs under earthquake records are conducted in two steps. At first, the nonlinear time-history analyses of two types of CSWs are carried out using RUAUMOKO program and the deficiencies of old-designed CSW are identified through the comparison of obtained results. In the second step, the old design CSW is retrofitted using CFRP sheets and reanalysed to investigate the benefits of the retrofit technique in mitigating the shortcomings. The results indicate that CFRP retrofitting is an efficient method to enhance the seismic performance of deficient old CSWs in terms of story displacement, inter-story drift, CBs rotation, and ductility demand. [ABSTRACT FROM AUTHOR]

A preliminary techno-economic evaluation of retrofitting reciprocating internal combustion engine based cogeneration into existing Canadian houses for the purpose of achieving or approaching net-zero energy rating is presented. Primary energy and electricity consumption, associated greenhouse gas emissions and tolerable capital cost are used as indicators. A whole building simulation model was used to simulate the performance of a commonly used cogeneration system architecture with thermal storage in “typical” single storey houses located in Halifax, Montreal, Toronto, Edmonton and Vancouver, representing the five major climatic regions of Canada. The system is assumed to sell excess electricity to the grid at the purchase price. A high efficiency auxiliary boiler is included to supply heat when cogeneration unit capacity is not sufficient to meet the heating load. The effect of thermal storage capacity, interest rate and acceptable payback period on the overall performance was evaluated through a sensitivity analysis. The findings suggest that internal combustion engine based cogeneration provides a promising option to achieve net-zero energy rating for Canadian houses, and therefore more detailed studies focusing on the entire Canadian housing stock are needed. [ABSTRACT FROM AUTHOR]

Unreinforced masonry (URM) infill walls are extensively used in buildings; they are normally considered as nonstructural components and their structural effects are often neglected in seismic analysis. However they interact with their bounding frame under seismic actions resulting in significant changes in the dynamic properties of the building, which can lead to structural damage and increased floor accelerations. To evaluate the structural contribution of infill walls, two eleven-storey wings of a paediatric research hospital located in Montreal, Canada, have been selected as a case study. A detailed elastic finite element model was generated which included the infill walls. Ambient vibration measurements were also done in both buildings to extract their dominant dynamic properties and calibrate the numerical models. Subjecting the calibrated models to a set of ground accelerograms, interstorey-drift curves and floor response spectra were developed. The effects of seismic retrofit and infill walls on the dynamic properties and seismic response of the buildings were addressed by comparing the results of different numerical models• [ABSTRACT FROM AUTHOR]

One of the most significant sources of greenhouse gas (GHG) emissions in Canada is the buildings sector, with over 30% of national energy end-use occurring in buildings. Energy use must be addressed to reduce emissions from the buildings sector, as nearly 70% of all Canada's energy used in the residential sector comes from fossil sources. An analysis of GHG emissions from the existing residential building stock for the year 2010 has been conducted for six Canadian cities with different climates and development histories: Vancouver, Edmonton, Winnipeg, Toronto, Montreal, and Halifax. Variation across these cities is seen in their 2010 GHG emissions, due to climate, characteristics of the building stock, and energy conversion technologies, with Halifax having the highest per capita emissions at 5.55 tCO2e/capita and Montreal having the lowest at 0.32 tCO2e/capita. The importance of the provincial electricity grid's carbon intensity is emphasized, along with era of construction, occupancy, floor area, and climate. Approaches to achieving deep emissions reductions include innovative retrofit financing and city level residential energy conservation by-laws; each region should seek location-appropriate measures to reduce energy demand within its residential housing stock, as well as associated GHG emissions. [ABSTRACT FROM AUTHOR]

The main use of energy in the residential sector in Canada is for space heating. Reductions in residential energy use, therefore, are likely to be achieved primarily through energy-saving retrofits, such as improved insulation. Reasons advanced to explain the foot-dragging of the residential sector in this regard are examined here, along with various policy options. Canadian survey data from 2003 are used to examine and compare the most energy-inefficient households who saw no need for retrofits with other households who provided a similar response, with a view to assessing whether there are factors that can be exploited to increase the uptake of such retrofits. The results suggest there is likely to be no quick fix. In the absence of large retrofit subsidies, with their accompanying free-rider problem, or a multi-pronged strategy that includes a whole array of policy instruments, including one that changes the relative importance of energy costs in household budgets, the outlook for sizeable improvements in residential energy efficiency in Canada via residential retrofits does not appear to be overly promising. [ABSTRACT FROM AUTHOR]

Abstract: In 1998 the Canadian government introduced the EnerGuide for Houses (EGH) program, essentially consisting of home energy audits with financial incentives provided to the homeowner upon verification that sufficient auditor-recommended upgrades were undertaken to achieve energy savings. In this study, we analyze the EGH data compiled between October 1998 and September 2005 to determine what types of households chose to participate and what appear to be the main factors underlying retrofit decisions. In the program, homeowners were prescribed specific upgrade types in the first audit. Hence, the decision problem involves whether to retrofit at all and how many of the prescribed upgrades to adopt. Moreover, the second audit that reveals this decision does not reflect the possibility that some homeowners might have undertaken the recommended upgrades but opted not to or have yet to undergo the second audit. We adopt an econometric technique that takes these features of the data into account. We find that energy cost savings, financial incentives, and costs of retrofits are important factors behind retrofit decisions given several other home- and household-specific characteristics. [Copyright &y& Elsevier]

Abstract: Private and public sectors own and operate an array of office buildings that consume energy and contribute to the emission of greenhouse gases (GHG). Energy demands can be reduced by applying energy retrofit measures (ERMs) to existing buildings. The choice of ERMs involves evaluation of applicability, energy end uses and cost of application versus energy savings. This paper describes a methodology developed to screen office buildings for their current level of energy consumption and potential for retrofit application. Selection of an optimal set of ERMs is influenced by climate, occupancy, heating and cooling systems, envelope properties and building geometry. When assessing the implications of applying ERMs to a large building stock it is vital to screen the complete building set for optimal retrofit opportunities. This can be accomplished by characterizing office building stock into a manageable set of archetypes and simulating building operation using energy simulation software. Using regression analyses, a model was developed for estimating the energy consumption. Present value analysis was used to optimize the evaluation of the various ERMs. The methodology developed can be used to simplify the ranking of buildings for retrofit; to select and combine ERMs, and to plan energy and GHG reduction activities. [ABSTRACT FROM AUTHOR]

Retrofitting with fibre reinforced polymers (FRP) to strengthen and repair damaged structures is a relatively new technique. In an extensive research program underway at the University of Toronto, application of FRP in concrete structures is being investigated for its effectiveness in enhancing structural performance both in terms of strength and ductility. The structural components tested so far include slabs, beams, columns and bridge culverts. Research on columns has particularly focussed on improving their seismic resistance by confining them with FRP. All the specimens tested can be considered as full-scale to two-third scale models of the structural components generally used in practice. Results so far indicate that retrofitting with FRP offers an attractive alternative to the traditional techniques. In many circumstances, it can provide the most economical (and superior) solution for a structural rehabilitation problem. Selected results from experimental and analytical research are presented in this paper. [Copyright &y& Elsevier]

This paper reviews the factors and criteria for the design of new and the retrofitting of existing dry detention ponds to enhance removal of total suspended solids (TSS) from stormwater. Detention time is discussed as the most important factor affecting TSS removal. Two-stage facilities and multi-level outlet design are important means of enhancing TSS removal in dry ponds. Two dry ponds within the city of Edmonton were selected to evaluate their TSS removal. The level of expected TSS removal is low owing to the relatively short detention times for both ponds. Methods for retrofitting the dry ponds to enhance TSS removal are discussed.Key words: dry pond, stormwater, TSS removal, detention time, retrofitting.Cet article passe en revue les facteurs et critères de conception de nouveaux étangs de rétention, et de modification de ceux déjà existants, avec pour but d'améliorer la capacité d'enlèvement des substances solides totales en suspension (SST) contenues dans les eaux de ruissellement. Le temps de rétention est examiné en tant que facteur principal affectant l'enlèvement des SST. Les installations à deux étages et la conception de sorties multi-niveaux sont des procédés importants qui améliorent l'enlèvement des SST dans les étangs. Deux étangs de la Ville d'Edmonton ont été sélectionnés et leur capacité de rétention a été évaluée. Le niveau d'enlèvement des SST escompté est bas compte-tenu des temps de rétention relativement courts de ces deux étangs. Les méthodes de modification des étangs visant à améliorer l'enlèvement des SST sont examinées.Mots clés : étang, eaux de ruissellement, enlèvement des SST, temps de rétention, réajustement.[Traduit par la Rédaction] [ABSTRACT FROM AUTHOR]

The impact of various energy efficiency upgrade scenarios on the annual energy consumption of the Canadian housing stock is assessed using the Canadian Residential Energy End-use Model (CREEM). The energy efficiency upgrade scenarios that are considered include major retrofits, such as the improvement of the house envelope by adding insulation, and the replacement of the existing heating system and appliances by higher efficiency units, as well as minor retrofits, such as lighting fixture, thermostat, showerhead and aerator upgrades that reduce energy consumption. The economic feasibility of each upgrade was assessed using the indicator ‘energy savings per dollar investment’. The results indicate that the energy savings potential of the retrofits is rather small, resulting in savings of 0–8 per cent of the total energy consumption of the Canadian housing stock. Copyright © 2001 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

The article presents information on the recent developments in the environmental laws and legislations of Minnesota. The vacating of the transport rule of the U.S. Environmental Protection Agency and the proposal of federal implementation plan by EPA related to the best available retrofit technology (BART) are discussed. The amendments to the Great Lakes Water Quality Agreement by the U.S. and Canada are also discussed.