@article {bnh-7922, title = {Improving the resilience of existing housing to severe wind events - final project report}, number = {656}, year = {2021}, month = {03/2021}, institution = {Bushfire and Natural Hazards CRC}, address = {Melbourne}, abstract = {

This BNHCRC project titled:\  Improving the resilience of existing housing to severe wind events prescribes practical structural retrofits that will make improvements to the performance of Pre-80s (Legacy) houses in windstorms as well as measures to reduce damage and loss to contemporary houses.

Damage investigations carried out by the Cyclone Testing Station (CTS) following severe windstorms have typically shown that houses built prior to the mid-1980s in Australia perform worse than houses constructed to contemporary building standards, during windstorms. Given that these older houses are a significant proportion of the housing stock, practical structural upgrading based on the latest research may improve performance of housing and the economic and social wellbeing of a community.

Some details for structural retrofitting currently exist, but their uptake is limited, and there is also evidence that these are not carried out when houses require repairs following severe storms. Therefore, the issues of retrofitting legacy housing, including feasibility and benefit-cost are analysed in this project.

The primary objective of this study was to identify vulnerable legacy house types across Australia and develop cost-effective retrofits for mitigating damage during windstorms. These evidence-based strategies will (a) aid policy formulation and decision making by Government and industry, and (b) provide guidelines detailing various options and benefits to homeowners and the industry for retrofitting typical at-risk houses in Australia. The main aims were to:

This report presents an overview of the research approach used for this project including the selection of house types, the development of the VAWS software and the Internet-based guidelines. A case study is presented of the vulnerability and benefit cost assessment of one of the selected house types, with the complete set of results presented in the Appendices. These results show that tile roofed houses in cyclonic regions of Australia benefit the most from retrofitting for severe wind events. The benefit-cost ratios for these tile roof houses and other house types are expected to improve when accounting for intangible costs, which are currently not included in the analyses presented in this report. In addition, examples of the impacts and utilisation of this project including the Queensland Government Housing Resilience Program are also presented.

}, keywords = {cyclone, events, existing housing, resilience, severe, wind}, issn = {656}, author = {John Ginger and Korah Parackal and David Henderson and Martin Wehner and Hyeuk Ryu and Mark Edwards} } @article {bnh-7300, title = {Improving the resilience of existing housing to severe wind events: annual report 2019-2020}, number = {607}, year = {2020}, month = {09/2020}, institution = {Bushfire and Natural Hazards CRC}, address = {Melbourne}, abstract = {

This BNHCRC project titled:\  Improving the resilience of existing housing to severe wind events prescribes practical structural retrofits that will make improvements to the performance of Pre-80s (Legacy) houses in windstorms as well as measures to reduce damage and loss to modern homes.

The major activity carried out in 2019-20 by the CTS-JCU and GA has been refining the VAWS software package using detailed wind loading and structural response test data and conducting a benefit-cost analysis for a range of retrofit or mitigation options:\ 

The retrofit options for the ten selected house types are also being provided as guideline in a website that is being produced. In line with the project timeline, an alpha version of this tool will be presented to Stakeholders in the next Quarter with the intention of having the final version released at the end of the project.

This project continues to give advice to the Queensland Government Household Resilience Program which provides funding to low income eligible home owners to improve the resilience of their homes against cyclones. This program managed by the Queensland Department of Housing \& Public Works (QDHPW) commenced in late 2018 and has been extended through 2020. Eligible home owners can apply to receive a Queensland Government grant of 75\% of the cost of improvements (up to a maximum of $11,250 including GST. About 1700 houses have been retrofitted so far.\ 

}, keywords = {Housing, resilience, severe wind}, issn = {607}, author = {Korah Parackal and Martin Wehner and John Ginger and Hyeuk Ryu and David Henderson and Mark Edwards} } @article {bnh-6885, title = {Progressive failures of batten to rafter connections under fluctuating wind loads}, journal = {Engineering Structures}, volume = {215}, year = {2020}, month = {05/2020}, abstract = {

Batten to rafter connections in light framed timber housing can be vulnerable to wind loading, and failures of these connections are one of the more common failure modes seen in post windstorm damage surveys. Such failures often occur in a progressive or cascading manner resulting in the loss of a large section of the roof envelope. These progressive failures of batten to rafter connections are a complex process influenced by the pressure fluctuations on the roof surface, the response of individual connections and the behaviour of the structural system as a whole. This study presents a method for examining load redistribution and progressive failure behaviour of batten to rafter connections in light framed structures. Nonlinear time history analyses were performed using a finite element model using fluctuating pressures determined from a wind tunnel study and connection properties determined from laboratory testing of connections under dynamic loads.

}, keywords = {Light framed structures, Low-rise buildings, progressive failures, wind loads}, doi = {https://doi.org/10.1016/j.engstruct.2020.110684}, url = {https://www.sciencedirect.com/science/article/abs/pii/S0141029619346395}, author = {Korah Parackal and John Ginger and David Henderson} } @article {bnh-5494, title = {Analysis of damage surveys of houses and preliminary input of VAWs}, number = {477}, year = {2019}, month = {04/2019}, institution = {Bushfire and Natural Hazards CRC}, address = {Melbourne}, abstract = {

Significant financial loss in terms of cost of rebuilding or repair and loss of function of property (e.g. commercial activity, rental, relocation of residents, etc.), has been documented following recent severe tropical cyclones impacting the Australian coastal communities. These damage investigations estimate that the wind speeds in these events were less than the Australian building standard{\textquoteright}s design level wind speed for the regions impacted. Analysis of insurance claims data highlights issues with wind driven rain water damage. Additionally, investigations of the damaged buildings along with analysis of claims data reveals a high proportion of the losses are associated with contemporary construction as opposed to pre-current code buildings.\ 

Education and awareness of consequences of such failures (e.g. damage to property and risk to life) is required in all steps of the building process (regulation, design, construction, certification and maintenance) and by all parties (designer, builder, certifier, and owner).

}, keywords = {building risk, resilience, severe wind, VAWs}, author = {David Henderson and Daniel Smith and Korah Parackal and John Ginger} } @article {bnh-6311, title = {Community benefits of roof upgrades}, number = {528}, year = {2019}, month = {12/2019}, institution = {Bushfire and Natural Hazards CRC}, address = {Melbourne}, abstract = {

Legacy houses (Houses built Pre-1982) are at risk of damage from wind loads due to the often inadequate roof hold down provided by connection details. Improving wind resistance through replacing roof connections or retrofitting the existing structure can greatly improve building performance and community safety. The Queensland Government Household Resilience Program (HRP) provides funding to help eligible home owners improve the resilience of their homes against cyclones. This program developed with advice from the Cyclone Testing Station is managed by the Queensland Department of Housing \& Public Works (QDPWH) and commenced in late 2018.

}, keywords = {community resilience, cyclones, Emergency management, engineering, resilience, roof, Severe Weather}, issn = {528}, author = {Korah Parackal and John Ginger and David Henderson and Martin Wehner} } @article {bnh-6276, title = {Improving the resilience of existing housing to severe wind events - annual report 2018-19}, number = {524}, year = {2019}, month = {12/2019}, institution = {Bushfire and Natural Hazards CRC}, address = {Melbourne}, abstract = {

This project will provide practical structural retrofits that will make a significant improvement in the performance of Pre-80s (Legacy) houses to wind loads. The major activity carried out in 2018-19 by the CTS-JCU and GA has been progressing the VAWS software package using wind loading and structural response and other test data:

This project has also provided advice to the Queensland Government Household Resilience Program which provides funding to help eligible home owners improve the resilience of their homes against cyclones. This program is managed by the Queensland Department of Housing \& Public Works (QDHPW) and commenced in late 2018. Eligible home owners can apply to receive a Queensland Government grant of 75\% of the cost of improvements (up to a maximum of $11,250 including GST. About 2000 houses have been retrofitted.

}, keywords = {building resilience, cyclones, Emergency management, engineering, Housing, severe wind, storms, structural design}, issn = {524}, author = {John Ginger and Korah Parackal and Martin Wehner and Hyeuk Ryu and David Henderson and Mark Edwards} } @article {bnh-5434, title = {Improving the resilience of existing housing to severe wind events in Australia Annual Report 2017-2018}, number = {465}, year = {2019}, month = {03/2019}, institution = {Bushfire and Natural Hazards CRC}, address = {Melbourne}, abstract = {

This project will propose practical structural upgrading solutions based on the latest research that will make a significant improvement in the performance of Pre-80s (Legacy) houses that are impacted by severe windstorms. The project has analysed existing structural retrofitting details available for some forms of legacy housing and has found that uptake is limited, even when these houses require major repairs following severe storm events. The work carried out in 2017-18 has focussed on developing cost-effective strategies for mitigating damage to housing from severe windstorms. The major activity has been progressing the VAWS software package by Geoscience Australia (GA) using wind loading and structural response data and other test data obtained by the CTS-JCU:

{\textbullet} Residential structures (i.e. Houses) have been categorized into types based on building features that influence windstorm vulnerability using CTS and GA housing survey data. Two house types were selected and incorporated in the VAWS package. The structural response (i.e. damage progression) with increasing wind speed has been modelled and validated. Testing carried out as part of BNHCRC supported thesis projects have provided additional data.

{\textbullet} Retrofit options and cost-benefit modules will be added to the VAWS model by GA and made available for trialling by end users and stakeholders (i.e. homeowners, builders, regulators, insurers). End-users and stakeholders will be asked to evaluate VAWS and suggest amendments and provide feedback on practicality and aesthetics of potential upgrading methods for these house types. Cost effective guides will be developed for vulnerable house types.

{\textbullet} Case studies will be used to evaluate effectiveness of proposed retrofit solutions for risk reduction. Economic assessment using the same case studies will be used to promote (via the stakeholders and end users) uptake of practical retrofit options.

}, keywords = {housing structure, resilience, severe wind}, author = {David Henderson and John Ginger and Daniel Smith and Martin Wehner and Hyeuk Ryu and Mark Edwards} } @article {bnh-5506, title = {Internal pressures in a full-scale test enclosure with windward wall openings}, journal = {Journal of Wind Engineering and Industrial Aerodynamics }, volume = {189}, year = {2019}, month = {04/2019}, abstract = {

A single opening on the windward wall which generates large\ internal pressures\ in a building often defines the critical\ wind loadingstructural design\ criterion. This paper presents internal pressure fluctuations in a sealed\ Full-Scale Test\ Enclosure (FSTE) for a range of single windward wall opening configurations induced by atmospheric wind flow, to assess the influence\ opening size\ (i.e. S*\ =\ (A3/2/V)(as/U{\textasciimacron}h)2) has on the internal pressure. Damped\ Helmholtz\ resonance was observed for S* \> 0.88, with peak and standard deviation internal pressures being about 5\% higher than the\ external pressures\ when S* \> 1.9. Internal pressure fluctuations are attenuated when S* \< 0.75. The inertial coefficient\ CI\ is between 1.3 and 1.5 and the\ loss coefficientCL\ increases with increasing\ opening area(0.88\ \<\ S*\ \<\ 5.8) between 10 and 20. These parameters have a significant influence on the internal pressure fluctuations, and this controlled\ full-scale\ study carried out for the first time provides data for validating analytical and\ model-scale\ studies on internal pressure fluctuations in buildings.

}, keywords = {Full-scale, Helmholtz resonance, Inertial coefficient, Internal pressure, Loss coefficient, Low-rise buildings, Single opening}, doi = {https://doi.org/10.1016/j.jweia.2019.03.024}, url = {https://www.sciencedirect.com/science/article/pii/S0167610518310304}, author = {Humphreys, M and John Ginger and David Henderson} } @article {bnh-6333, title = {Model for assessing the vulnerability of Australian housing to windstorms - VAWS}, number = {529}, year = {2019}, month = {12/2019}, institution = {Bushfire and Natural Hazards CRC}, address = {Melbourne}, abstract = {

Modelling the vulnerability of houses in windstorms is important for insurance pricing, policy-making, and emergency management. Models for Australian house types have been developed since the 1970s, and have ranged from empirical models to more advanced reliability based structural engineering models, which provide estimates of damage for a range of wind speeds of interest. This report describes the development of a software program: Vulnerability and Adaption to Wind Simulation (VAWS), which uses probability based reliability analysis and structural engineering for the loading and response coupled with an extensive test database and field damage assessments to calculate the damage experienced by selected Australian house types.\ \ 

}, keywords = {building resilience, cyclone, Emergency management, engineering, severe wind, wind modelling}, issn = {529}, author = {Korah Parackal and Martin Wehner and Hyeuk Ryu and John Ginger and David Henderson and Mark Edwards} } @conference {bnh-6407, title = {Modelling the vulnerability of a high-set house roof structure to windstorms using VAWS }, booktitle = {Bushfire and Natural Hazards CRC Research Day AFAC19}, year = {2019}, month = {12/2019}, address = {Melbourne}, abstract = {

Modelling the vulnerability of houses in windstorms is important for insurance pricing, policy-making, and emergency management. Vulnerability models for Australian house types have been developed since the 1970s and have ranged from empirical models to more advanced reliability based structural engineering models, which provide estimates of damage for a range of wind speeds of interest. This paper describes recent developments in the engineering based vulnerability modelling software: {\textquoteleft}Vulnerability and Adaption to Wind Simulation{\textquoteright} (VAWS), which uses probability based reliability analysis and structural engineering for the loading and response coupled with an extensive test database and field damage assessments to calculate the damage experienced by selected Australian house types. A case study is presented to demonstrate the program{\textquoteright}s ability to model progressive failures, internal pressurization and debris impact.

}, keywords = {debris, simulation, structures, VAWs, Vulnerability, wind}, url = {https://knowledge.aidr.org.au/resources/australian-journal-of-emergency-management-monograph-series/}, author = {Korah Parackal and Martin Wehner and Hyeuk Ryu and John Ginger and Daniel Smith and David Henderson and Mark Edwards} } @article {bnh-6666, title = {Rainwater ingress through residential sliding doors}, number = {545}, year = {2019}, month = {06/2019}, institution = {Bushfire and Natural Hazards CRC}, address = {Melbourne}, abstract = {

Damage investigations carried out following windstorms have shown significant damage caused by rainwater ingress (Boughton, Falck et al. 2017). A preliminary experimental study was carried out at the Cyclone Testing Station (CTS) that simulated wind driven rain on a residential window under strong wind conditions to observe rainwater ingress.

The external pressures on a building envelope vary in time and space on the surface of a building with windward walls experiencing positive pressures and all other surfaces (side and leeward walls and roof) subjected to negative pressures.

Internal pressure fluctuations in a nominally sealed building with a porous envelope, are generally much lower than the external pressure fluctuations. This internal pressure is usually a small suction pressure and hence the net (i.e. (external {\textendash} internal)) pressure across the windward wall is positive but negative across the other surfaces. This pressure differential along with wind driven rain can result in air-entrained water ingress into the building through windows that are closed due to gaps and weep-holes.

Preliminary tests were conducted at the CTS on a window attached to the wind driven rain simulator (WDRS) to assess rainwater leakage and potential measures that could reduce leakage.

}, keywords = {ingress, rainwater, sliding doors}, issn = {545}, author = {Korah Parackal and John Ginger and Leblais, Alex and David Henderson} } @article {bnh-6656, title = {Retrofitting of a high-set Queensland house for wind loading}, number = {541}, year = {2019}, month = {06/2019}, institution = {Bushfire \& Natural Hazards CRC}, address = {Melbourne}, abstract = {

This report presents a preliminary study on the retrofitting/upgrading of roofing connections in an older Australian house type to improve its performance under wind loading. The house type selected is a rectangular plan high-set house with a low pitched gable roof. These houses are common in North Queensland and have been the subject of previous vulnerability studies by the Cyclone Testing Station. In previous studies this house type is also known as the {\textquoteleft}Group-4 House{\textquoteright}.

Vulnerability to wind loads of a population of these houses will be estimated using the Vulnerability and Wind Simulation (VAWS) software that is currently under development by the Cyclone Testing Station and Geoscience Australia. The changes to vulnerability functions for four connection upgrading scenarios are investigated. These preliminary analyses are used to inform initial cost benefit estimates for retrofitting older Australian houses.

}, keywords = {Housing, retrofitting, roofing, wind loading}, issn = {541}, author = {Korah Parackal and John Ginger and Martin Wehner and David Henderson} } @article {bnh-5161, title = {Distribution of wind loads in metal-clad roofing structures}, journal = {Journal of Structural Engineering}, volume = {144}, year = {2018}, month = {04/2018}, abstract = {

The roof is the part that experiences the largest wind load and is usually the most vulnerable part of a house. However, data on how the wind loads are transferred through the roof structure are scarce. The fluctuating nature and variable spatial distribution of wind loads combined with the structural response can cause significant challenges for assessing the distribution or sharing of loads in a roof. Such studies are required to obtain more reliable estimates on vulnerability assessment to windstorms. This paper describes the transmission of wind loads from the pressure on the cladding through the cladding-to-batten connections to the batten-to-truss connections on a roofing system typical of that in many contemporary houses constructed in cyclonic regions of Australia. The study found that the use of normal design practices can significantly underestimate connection loads when highly correlated large-scale wind pressures act on these roof systems.

}, doi = {https://doi.org/10.1061/(ASCE)ST.1943-541X.0001992}, url = {https://ascelibrary.org/doi/10.1061/\%28ASCE\%29ST.1943-541X.0001992}, author = {Nandana Jayasinghe and John Ginger and David Henderson and George Walker} } @article {bnh-6054, title = {Fragility and climate impact assessment of contemporary housing roof sheeting failure due to extreme wind}, journal = {Engineering Structures}, volume = {117}, year = {2018}, month = {09/2018}, pages = {464-475}, abstract = {

The paper describes a risk analysis of the economic impact of damage to metal roofing of a typical contemporary (new) Australian house subject to extreme wind loading. The failure modes considered are roof cladding and batten-to-truss connection failures, with the effect of defective construction also considered. Monte-Carlo simulation and structural reliability methods are used to stochastically model spatially varying pressure coefficients, roof component failure, and load re-distribution across the roof. This spatial reliability analysis enables fragility curves to be developed that relate likelihood and extent of roof cover loss to gust wind speed. The annual economic risk is up to 0.3\% of house replacement value. A typical house with construction defects increases economic risk more than sixfold when compared to the defect-free house. There is a 10\% chance that a changing climate will increase expected losses for houses in Brisbane and Melbourne by 6{\textendash}18\% over the next 50 years.

}, keywords = {Climate change, Damage, Fragility, Housing, Reliability, Wind load}, doi = {https://doi.org/10.1016/j.engstruct.2018.05.125}, url = {https://www.sciencedirect.com/science/article/pii/S0141029618302499}, author = {Mark Stewart and John Ginger and David Henderson and Paraic Ryan} } @conference {bnh-4790, title = {Large damage bills to buildings from cyclones can be reduced by small actions}, booktitle = {AFAC18}, year = {2018}, month = {09/2018}, publisher = {Bushfire and Natural Hazards CRC}, organization = {Bushfire and Natural Hazards CRC}, address = {Perth}, abstract = {

Recent severe tropical cyclones and storms impacting Australian cities and towns have resulted in large financial losses due to damaged buildings and property. Disruption to livelihoods during the repair/rebuilding prolongs recovery for the community. Damage investigations by the Cyclone Testing Station estimate the wind speeds for the majority of the regions investigated were less than the design wind speeds for contemporary construction (i.e. for buildings less than 35 years old). The damage building assessments show a significant proportion of the losses are due to contemporary buildings. This raises issues as to appropriateness of our building construction, Codes, engineering design practices, and ongoing maintenance.

}, author = {David Henderson and Daniel Smith and John Ginger} } @article {bnh-5219, title = {Simulated wind load strength testing of entrance doors}, year = {2018}, month = {12/2018}, institution = {Bushfire and Natural Hazards CRC}, address = {Melbourne}, abstract = {

Damage investigations following cyclonic events have shown failure of doors and windows as illustrated in Figure 1 and Figure 2. Failure of such elements leads to further damage to the building by allowing rain and wind to enter the house. In addition to water damage to contents and internals, this creates increased stress to the building envelope due to the increased internal pressure as illustrated in Figure 3, which can lead to further failure such as roof failure.

Small weaknesses can therefore lead to large failures.

The study {\textquotedblleft}Design of Potential Dominant Opening to Resist Cyclonic Winds{\textquotedblright} by Nicoline Thomson, David Henderson and John Ginger highlights the under design of a standard external door for cyclonic conditions. Following this study, additional tests were conducted, replacing the timber doorframe with a steel doorframe and assessing various types of doors and lock mechanisms under cyclonic conditions.

The aim of this test programme was to perform full-scale simulated wind load strength testing of these different configurations of entrance doors. The AS 4040.2 static and AS 4040.3 cyclic simulated wind load strength test regimes\ were used as guides to load the test doors.

}, issn = {450}, author = {Leblais, Alex and David Henderson} } @article {bnh-5218, title = {Simulated wind load strength testing of soffits}, year = {2018}, month = {12/2018}, institution = {Bushfire and Natural Hazards CRC}, address = {Melbourne}, abstract = {

Damage investigations following cyclonic events have shown failure of soffit lining, including on contemporary buildings, as illustrated in Figure 2 to Figure 12. Failure of soffit lining can lead to further major damage to the building by allowing wind driven rain to enter the ceiling attic, causing the ceilings to collapse and further water damage. In addition to water damage to contents and internals, soffit lining failure creates increased stress to the building envelope due to the increased internal pressure caused by wind entering the roof cavity through the eaves, which can lead to further failure such as roof failure.

Small weaknesses can therefore lead to large failures.

This report uses results, and summarises parts, of the thesis {\textquotedblleft}Design of soffits and eaves to resist wind loads in cyclonic regions{\textquotedblright} by Lalin Chhoeuk, in particular the mechanical assessment of various combinations of soffit lining to batten connections to evaluate their suitability for use in cyclonic regions.

The aim of this test programme was to perform full-scale simulated wind load strength testing of these different configurations of soffit lining to batten connections. The AS 4040.2 static simulated wind load strength test regimes was used as guides to load the test specimens.

The simulated wind load strength tests were conducted in an airbox testing facility located at the Cyclone Testing Station at James Cook University.

}, issn = {449}, author = {Leblais, Alex and David Henderson} } @article {bnh-4467, title = {Wind load fluctuations on roof batten to rafter/truss connections}, journal = {Journal of Wind Engineering \& Industrial Aerodynamics}, volume = {175}, year = {2018}, month = {02/2018}, abstract = {

Batten to rafter connections in light framed housing can be vulnerable to progressive or cascading failures where a localised failure can cause the loss of a large section of the roof envelope. The synchrony of loads at neighbouring connections may affect the initiation of such failures. A 1/50 length scale wind tunnel model study was performed on a gable roof house to record spatial and temporal pressure fluctuations on the roof surface and data were studied to determine the flow separation mechanisms causing different loading patterns on batten to rafter connections. The cross correlation between load time histories was used to give a measure of synchrony between loads experienced at neighbouring connections and indicate the direction that fluctuations move across the roof. Orthogonal wind directions result in 2-dimensional flow separation that produce more synchronous loads at batten to rafter connections than cornering wind directions, where conical vortices produce high uplift forces on connections. The patterns of loading and their correlations give a means of identifying which parts of the roof and which approach wind directions may result in the initiation of a progressive failure of batten to rafter connections.

}, keywords = {Correlation of loads, Light framed structures, Low-rise buildings, Progressive failures., Wind tunnel study}, doi = {https://doi.org/10.1016/j.jweia.2018.01.032}, url = {https://www.sciencedirect.com/science/article/pii/S0167610517304506}, author = {Korah Parackal and John Ginger and David Henderson} } @article {bnh-5162, title = {Analysis of rapid damage assessment data following severe windstorm events}, journal = {Australian Journal of Emergency Management}, volume = {32}, year = {2017}, month = {10/2017}, abstract = {

The Cyclone Testing Station (CTS) and partners have conducted forensic damage assessments in Australia following severe windstorm events for over four decades. The information collected is used for building science research that provides the evidence base needed for improvements to building codes and development of damage mitigation solutions. The Queensland Fire and Emergency Services (QFES) operate Rapid Damage Assessment (RDA) teams in the aftermath of major disasters (e.g. cyclone and bushfire) to collect and disseminate information on extent of damage to buildings in impacted communities. These data enables focused and coordinated response in the immediate aftermath of an event and better planning for event recovery. This paper explores the use of QFES RDA datasets in analysing the damaging effects of severe windstorm events. Two case studies are discussed: a supercell that hit Brisbane on 27 November 2014 and Tropical Cyclone Debbie that made landfall along the northern Queensland coastline in March 2017. Where possible, damage data are combined with hazard information (dual-Doppler radar horizontal wind fields) and their relationship is investigated. The analysis demonstrates that RDA data are not only useful in response and recovery phases, but also have value for research aiming to better understand building failures and reduce damage in future events.

}, url = {https://ajem.infoservices.com.au/items/AJEM-32-04-21}, author = {Daniel Smith and Richard Krupar III and David Henderson and M. S. Mason} } @article {bnh-3957, title = {Development of a full-scale structural testing program to evaluate the resistance of Australian houses to wind loads}, journal = {Frontiers in Built Environment}, year = {2017}, month = {04/2017}, abstract = {

Extensive damage to houses during severe tropical cyclones in the 1970s in Australia highlighted the need for research-based structural engineering principles to be applied in design and construction of houses. Houses have structural redundancies and complex load paths, so the analysis of even simple houses was complicated. In order to evaluate the structural performance of these parallel systems, full-scale house testing commenced at the Cyclone Testing Station (CTS) in the early 1980s with the static multipoint loading of an old house destined for demolition. Following that test program, nine full-scale houses were tested under static and cyclic loading to evaluate load paths in different types of houses with different building practices and materials. Results have been incorporated into amendments of house construction codes, standards, and manuals. Advances in computer modeling and instrumentation have led to more sophisticated full-scale studies. Data on real houses under construction have informed this work and enabled analytical models to incorporate variability in strength of connections in a way that a single test cannot. Progressive failure in the structural systems of timber-framed housing can now be studied to differentiate between houses that have significant damage and seemingly identical ones that have limited damage in the same wind event. These studies involve wind tunnel investigations to determine temporal pressure distributions; full-scale multiple tests on connections (with and without construction defects) to determine statistical distributions of strength and load/deflection relationships; and full-scale tests on houses or portions of houses to determine load sharing mechanisms between parallel structural and non-structural elements. The results of the test programs were used to calibrate the analytical models, which can be used for reliability studies. The paper presents a summary of the methodology and findings from previous CTS full-scale house tests. The results of the most recent research using full-scale tests on a portion of a house and its companion numerical models are discussed and the benefits and limitations of the process outlined.

}, doi = {10.3389/fbuil.2017.00021}, url = {http://journal.frontiersin.org/article/10.3389/fbuil.2017.00021/full}, author = {Boughton, Geoffrey N. and Korah Parackal and Satheeskumar, N and David Henderson} } @article {bnh-4216, title = {Improving the resilience of housing to severe wind events: annual project report 2016-17}, number = {342}, year = {2017}, month = {09/2017}, institution = {Bushfire and Natural Hazards CRC}, address = {Melbourne}, abstract = {

Damage investigations carried out by the Cyclone Testing Station (CTS) following severe wind storms have typically shown that Australian houses built prior to the mid-1980s do not offer the same level of performance and protection during windstorms as houses constructed to contemporary building standards. Given that these older houses will represent the bulk of the housing stock for many decades, practical structural upgrading solutions based on the latest research will make a significant improvement to housing performance and to the economic and social well-being of the community.

Structural retrofitting details exist for some forms of legacy housing but the uptake of these details is limited. There is also evidence that retrofitting details are not being included into houses requiring major repairs following severe storm events, thus missing the ideal opportunity to improve resilience of the house and community. Hence, the issues of retrofitting legacy housing, including feasibility and hindrances on take-up, etc., must be analysed.

The primary objective of this research is to develop cost-effective strategies for mitigating damage to housing from severe windstorms across Australia. \ These evidence-based strategies will be (a) tailored to aid policy formulation and decision making in government and industry, and (b) provide guidelines detailing various options and benefits to homeowners and the building community for retrofitting typical at-risk houses in Australian communities. Specific task items include:

}, issn = {342}, author = {David Henderson and Daniel Smith and John Ginger and Martin Wehner and Hyeuk Ryu and Mark Edwards} } @conference {bnh-3922, title = {Load sharing between batten to rafter connections under wind loading}, booktitle = {13th Americas Conference on Wind Engineering}, year = {2017}, month = {05/2017}, address = {Gainesville, Florida}, abstract = {

Single nailed batten to rafter connections of non-cyclonic region houses were tested under quasi-static ramp loads and under fluctuating dynamic loads determined from a wind tunnel study. Dynamic connection testing showed that nails of connections slip during intermittent {\textquoteleft}peak events{\textquoteright} in the wind load time history with connection failure occurring after several peak events. Non-linear time-history structural analysis was performed on a system of batten to rafter connections where connection testing data were used to model the nominal force-displacement relationships of the nailed connections. This preliminary computer analysis was able to capture the effects of load sharing and redistribution during nail slips and progressive failures.

}, url = {https://www.researchgate.net/publication/317411903_Load_Sharing_Between_Batten_to_Rafter_Connections_under_Wind_Loading}, author = {Korah Parackal and John Ginger and D. J. Smith and David Henderson} } @article {bnh-4230, title = {Severe wind hazard preliminary assessment: Tropical Cyclone Debbie, Whitsunday Coast, Queensland, Australia}, year = {2017}, month = {03/2017}, institution = {James Cook University}, address = {Townsville}, abstract = {

Severe Tropical Cyclone Debbie was a category 4 system that made landfall near Airlie Beach (Figure 1) on the north Queensland coast at midday on the 28th of March, 2017. As part of a continuing effort to better characterize wind fields that impact communities during severe wind events, the Cyclone Testing Station (with collaborators from the Wind Research Laboratory at The University of Queensland) deployed SWIRLnet (Surface Weather Relay and Logging Network) weather stations to the region prior to Debbie{\textquoteright}s landfall. Six SWIRLnet towers (3.2 m high anemometers placed in the communities likely to be affected) collected data continuously prior to, during and after landfall. Three towers were deployed in the Ayr/Home Hill region, two in Bowen and one in Proserpine (Figure 2). This Preliminary Assessment Report details the initial observations from these towers, compares these with Bureau of Meteorology Automatic Weather Station observations, and makes some preliminary comment on the damage to structures in stormaffected communities.

}, url = {https://www.jcu.edu.au/__data/assets/pdf_file/0005/422951/TC-Debbie-Rapid-Assessment-Report_v8.pdf}, author = {Thomas Kloetzke and Korah Parackal and D. J. Smith and Richard Krupar III and Leblais, Alex and Humphreys, M and Spassiani, Alessio and M. S. Mason and David Roueche and David O Prevatt and David Henderson and Boughton, Geoffrey N.} } @article {bnh-4148, title = {Testing of simulated flood effect on the strength of selected building components}, number = {334}, year = {2017}, month = {06/2017}, institution = {Bushfire and Natural Hazards CRC}, address = {Melbourne}, abstract = {

This report presents the results of tests conducted to ascertain the resilience of selected building components to floodwater exposure. The experimental test programme was part of the Bushfire and Natural Hazards Collaborative Research Centre (BNHCRC) project entitled {\textquotedblleft}Cost-effective mitigation strategy development for flood prone buildings{\textquotedblright}.

The motivation for this project arises from the experience and observations made during the recent flooding in Australia in 2011 and 2013, which caused widespread devastation in Queensland. The objective of the project is to address the vulnerability of existing residential building stock in Australian floodplains and is targeted at assessing cost-effective mitigation strategies to reduce the vulnerability.

Geoscience Australia as the lead researcher for the project selected the Cyclone Testing Station at James Cook University in Townville, Queensland, to conduct the experimental tests. These tests aimed to address knowledge gaps in the areas of strength and durability implications of selected components of a typical brick veneer slab-on-grade house due to immersion.

The experimental programme was developed in consultation with insurance industry loss assessors from two major companies and was scoped in recognition of the available budget. The objective of the testing was to identify whether the selected components remain serviceable following inundation and subsequent drying or whether replacement was required.

The experimental programme examined the resistance to inundation of three common building components as outlined below. For each component, a number of samples were tested to attempt to provide some understanding of the variation of resistance. For each component some specimens were tested dry without wetting and some were tested after drying following inundation. For Component 3, some specimens were also tested wet immediately after inundation.

The results of the tests showed that flooding did not have any significant effect on the pull-out strength of the bond of the ceramic floor and wall tiles to their substrate, nor on the racking strength of the OSB wall sheet bracing. There was a nominal strength reduction of 10\% for the HDF wall sheet bracing when tested after wetting and drying cycle.

However, there was a significant reduction (~46\%) in load carrying capacity of the timber joists when tested in the wet condition. These results suggest that the samples whilst in the wet stage may be compromised due to reduced strength capacity and stiffness. However, if allowed to dry then the specimen could recover to nominally 96\% of average strength capacity and stiffness. Moreover, it was observed that the moisture content level after the test returned close to pre-inundation level within a week and therefore contributed to recover the strength and stiffness.

The results of the testing will inform recommendations on mitigation measures within the BNHCRC flood project. The results will also inform the selection of building materials for new construction in flood-prone areas.

}, issn = {334}, author = {Maqsood, T and Martin Wehner and Mark Edwards and Simon Ingham and David Henderson} } @article {bnh-4227, title = {Tropical Cyclone Debbie: damage to buildings in the Whitsunday Region}, number = {63}, year = {2017}, month = {06/2017}, institution = {James Cook University}, address = {Townsville}, abstract = {

Tropical Cyclone Debbie (TC Debbie) was classified by the Bureau of Meteorology (BoM) as a Category 4 cyclone and crossed the Queensland coast north east of Airlie Beach around midday on Tuesday 28 March 2017.

Before the event, the Cyclone Testing Station (CTS) deployed six mobile anemometers (SWIRLnet) in the area between Ayr and Proserpine. After the event, CTS teams investigated the performance of houses; larger residential structures such as apartments, strata properties and resort accommodation; commercial and public buildings; and sheds. The study area included the communities of Bowen, Proserpine, Airlie Beach, Hamilton Island, Dingo Beach, Wilson{\textquoteright}s Beach and Conway Beach. A wind field was developed using CTS and BoM anemometer data and showed that buildings within the study area experienced wind speeds lower than their relevant design wind speed.

CTS teams assessed the causes of damage to buildings from wind, wind-driven rainwater and storm surge. Inadequate tie-down details between battens and rafters or trusses, and between the roof structure and walls caused many of the structural failures in buildings constructed before the 1980s. Tie-down connections between roof structure and walls that had been inappropriately detailed also failed on some recently constructed buildings. Connections between verandah beams and posts on some buildings with larger verandahs also failed. \ 

This study confirmed the findings of previous damage investigations concerning the vulnerability of: windows with inadequate fixings, window and door furniture; poorly fixed flashings, gutters and soffit linings; large access doors that had not been strengthened so that they complied with AS/NZS4505; lightweight sheds; and fences.

Many occupants of newer buildings reported significant damage from wind-driven rain entering through windows and doors or under flashings even though there was no structural damage to the building. Many people reported that they mopped up water in front of windward wall windows during periods of maximum winds, which exposed them to risk of injury. Further research is required to improve performance of building elements that leak during high winds.

The storm tide generated during TC Debbie was lower than predicted because the cyclone crossed the coast after high tide. Lower-lying buildings in Wilson Beach were inundated to a height of up to 1.1 m causing damage to wall linings, built-in cupboards, floor coverings and contents. In some cases, wave action broke cladding elements and windows. Wave action and scour undercut footings in some buildings on Hamilton Island and Wilson Beach.\ 

The report provides recommendations to improve the performance of building structure and cladding systems including: adequate detailing for roof to wall connections; improved fixing of flashings, retrofitting options for older buildings; improvements in windows and door furniture under repeated wind loads; and revision of storm surge guidelines.

}, isbn = {978-0-9954470-4-2}, issn = {63}, url = {https://www.jcu.edu.au/__data/assets/pdf_file/0009/461178/TC-Debbie-report.pdf}, author = {Boughton, Geoffrey N. and Falck, D. J. and David Henderson and D. J. Smith and Korah Parackal and Thomas Kloetzke and M. S. Mason and Humphreys, M and Navaratnam, S and Bodhinayake, G and Simon Ingham and John Ginger} } @conference {bnh-2943, title = {Building community cyclone resilience through academic and community partnership}, booktitle = {AFAC16}, year = {2016}, month = {08/2016}, publisher = {Bushfire and Natural Hazards CRC}, organization = {Bushfire and Natural Hazards CRC}, address = {Brisbane}, abstract = {

This paper will present research from collaboration between the Cyclone Testing Station at James Cook University and insurer Suncorp over the last two years. A key outcome of this work in 2016 has been Suncorp{\textquoteright}s recognition of homeowner mitigation efforts through an insurance premium reduction program known as the {\textquoteleft}Cyclone Resilience Benefit{\textquoteright}. The research methods and findings that informed this program as well as other key outcomes including recommendations for codes and standards will be discussed. A broader context will also be presented including the political backdrop of the Productivity Commission inquiry into natural disaster funding and the recent Northern Australia Insurance Affordability Taskforce.

}, author = {Jon Harwood and D. J. Smith and David Henderson} } @conference {bnh-4158, title = {Correlation of peak wind loads at batten-truss connections}, booktitle = {18th Australasian Wind Engineering Society Workshop}, year = {2016}, month = {07/2016}, publisher = {Australasian Wind Engineering Society}, organization = {Australasian Wind Engineering Society}, address = {McLaren Vale}, abstract = {

Wind loads on roofs fluctuate significantly, both across their surfaces and in time. A 1/50 scale wind tunnel study was conducted to determine the correlations of these load fluctuations on batten to truss connections. This study found that load histories between neighbouring connections are correlated and are sensitive to wind direction. Critical wind directions that cause the highest uplift loads are not necessarily those that experience the highest correlations amongst neighbouring connections. Additionally, for different wind directions loads at connections to the left, right or diagonally across from the critical connections are more correlated, suggesting that the path that a progressive failure takes is dependent on wind direction and the location on the roof where it initiates.

}, author = {Korah Parackal and John Ginger and David Henderson} } @conference {bnh-3386, title = {Correlation of peak wind loads at batten-truss connections}, booktitle = {Mechanics of Structures and Materials XXIV}, year = {2016}, month = {12/2016}, publisher = {CRC Press}, organization = {CRC Press}, address = {Perth, Australia}, url = {https://www.crcpress.com/Mechanics-of-Structures-and-Materials-XXIV-Proceedings-of-the-24th-Australian/Hao-Zhang/p/book/9781138029934}, author = {Korah Parackal and John Ginger and David Henderson} } @article {bnh-3087, title = {Improving the resilience of existing housing to severe wind events: Annual project report 2015-2016}, number = {224}, year = {2016}, month = {09/2016}, institution = {Bushfire and Natural Hazards CRC}, address = {Melbourne}, abstract = {

Damage investigations carried out by the Cyclone Testing Station (CTS) following severe wind storms have typically shown that Australian houses built prior to the mid-1980s do not offer the same level of performance and protection during windstorms as houses constructed to contemporary building standards. Given that these older houses will represent the bulk of the housing stock for many decades, practical structural upgrading solutions based on the latest research will make a significant improvement to housing performance and to the economic and social well-being of the community.

Structural retrofitting details exist for some forms of legacy housing but the uptake of these details is limited. There is also evidence that retrofitting details are not being included into houses requiring major repairs following severe storm events, thus missing the ideal opportunity to improve resilience of the house and community. Hence, the issues of retrofitting legacy housing, including feasibility and hindrances on take-up, etc., must be analysed.

The primary objective of this research is to develop cost-effective strategies for mitigating damage to housing from severe windstorms across Australia.\  These evidence-based strategies will be (a) tailored to aid policy formulation and decision making in government and industry, and (b) provide guidelines detailing various options and benefits to homeowners and the building community for retrofitting typical at-risk houses in Australian communities. Specific task items include:

{\textbullet} \  Categorise residential structures into types based on building features that influence windstorm vulnerability using Geoscience Australia and CTS survey data. From these, a suite will be selected to represent those contributing most to windstorm risk

{\textbullet} \  Involve end-users and stakeholders (i.e. homeowners, builders, regulators, insurers) to assess amendments and provide feedback on practicality and aesthetics of potential upgrading methods for a range of buildings. Cost effective strategies will be developed for key house types

{\textbullet} \  Vulnerability models will be developed for each retrofit strategy using survey data, the authors{\textquoteright} existing vulnerability models, and the NEXIS database of Australian housing characteristics. Case studies will be used to evaluate effectiveness of proposed retrofit solutions in risk reduction. Economic assessment using the same case studies will be used to promote uptake of practical retrofit options.

}, issn = {224}, author = {Daniel Smith and David Henderson and John Ginger and Martin Wehner and Hyeuk Ryu and Mark Edwards} } @article {bnh-2856, title = {Towards effective mitigation strategies for severe wind events}, journal = {The Australian Journal of Emergency Management}, volume = {31}, year = {2016}, month = {07/2016}, abstract = {

The need to mitigate the losses from severe wind events in Australia has been highlighted repeatedly over the last decade, paralleling that of the hurricane-prone south-east United States of America. The Northern Australia Insurance Premiums Taskforce final report released in 2015, along with numerous other studies and reports, emphasised that mitigation is the only rational solution to reducing loss and improving the current insurance affordability situation. Engineering solutions exist to prevent failures, however post-event observations highlight their lack of implementation. It follows that the current level of community engagement in mitigation activities in cyclone-prone regions of Australia must be improved if losses are to be reduced. This paper discusses issues of engagement and reviews literature and existing mitigation programs as background for a smartphone mitigation tool being developed in Queensland, Australia, and Florida, USA. The Northern Australia Insurance Premiums Taskforce final report can be found at:\ www.treasury.gov.au/ConsultationsandReviews/Reviews/2015/NAIP-Taskforce/Final-Report.\ 

}, url = {https://ajem.infoservices.com.au/items/AJEM-31-03-14}, author = {Daniel Smith and Connor McShane and Anne Swinbourne and David Henderson} } @article {bnh-5099, title = {Wind loads on contemporary Australian housing}, journal = {Australian Journal of Structural Engineering}, volume = {17}, year = {2016}, month = {09/2016}, abstract = {

Design pressures given in wind loading standards are based on wind tunnel studies conducted during the 1970s to 90s on rectangular hip and gable roofs. However, most contemporary houses have complex hip-roof geometries with a range of plan footprints. Wind tunnel model studies were carried out on representative one- and two-storey houses to determine cladding design and truss hold-down loads. These loads were compared to design loads determined from wind loading standards AS/NZS 1170.2 and AS 4055. AS 4055 gave conservative design loads in most situations, and AS/NZS 1170.2 underestimated the loads near the windward edges and ridge on the roof. AS/NZS 1170.2 does give satisfactory design loads for wall cladding and truss hold down.

}, doi = {https://doi.org/10.1080/13287982.2016.1229375}, url = {https://www.tandfonline.com/doi/abs/10.1080/13287982.2016.1229375?journalCode=tsen20}, author = {Korah Parackal and Humphreys, M and John Ginger and David Henderson} } @article {bnh-3434, title = {Wind uplift strength capacity variation in roof-to-wall connections of timber-framed houses}, journal = {Journal of Architectural Engineering}, volume = {22}, year = {2016}, month = {02/2016}, abstract = {

The roof-to-wall connection in a house is designed to transfer the uplift and lateral loads during strong winds by providing a continuous load path from the roof to the foundation. The uplift capacity and failure mode of the connection depends on the number and type of fasteners (nails), timber species, type of framing anchor, and constructions defects. This paper presents experimental results that were used to assess the uplift capacity variation of typical roof-to-wall connections. Based on tests with two types of connections (triple grip and truss grip) assembled with two types of timber (radiata pine and spruce pine), nails (hand and gun), and framing anchors (triple grip and universal triple grip), the results show that the variation in timber species, nail, and triple grip type changes the strength and the failure modes of the connection. The strength of the connection was reduced by about 24\% when the timber species was changed from radiata pine to spruce pine and the hand nail to gun nail on the triple grip connection. This study also showed that construction defects in roof-to-wall connections influence the design uplift capacity. If there are two missing nails in the hand-nailed triple grip connection (i.e., one nail on the truss and another one on the top plate) the design uplift capacity reduces by about 40\% of the ideal hand-nailed triple grip connection. This study identified the critical nails and their locations required to mitigate failure of the roof-to-wall triple grip connection subject to wind loading.

}, doi = {10.1061/(ASCE)AE.1943-5568.0000204$\#$sthash.bMSTwFiH.dpuf}, url = {http://ascelibrary.org/doi/10.1061/\%28ASCE\%29AE.1943-5568.0000204}, author = {Satheeskumar, N and David Henderson and John Ginger and Wang, CH} } @conference {bnh-1619, title = {Improving the Resilience of Existing Housing to Severe Wind Events Conference Paper 2014}, booktitle = {Bushfire and Natural Hazards CRC and AFAC Wellington Conference 2014}, year = {2015}, month = {02/2015}, abstract = {

Damage investigations carried out by the Cyclone Testing Station (CTS) following severe wind storms have typically shown that Australian houses built prior to the mid-1980s do not offer the same level of performance and protection during windstorms as houses constructed to contemporary building standards. Given that these older houses will represent the bulk of the housing stock for many decades, practical structural upgrading solutions based on the latest research will make a significant improvement to housing performance and to the economic and social well-being of the community.
Some structural retrofitting details exist for some forms of older housing but the take up of these details is limited. There is also evidence that retrofitting details are not being included into houses requiring major repairs following severe storm events, thus missing the opportunity to improve resilience of the house and the community. Hence the issues of retrofitting of older housing including feasibility, and hindrances on take-up etc. must be analysed.
This paper describes a Bushfire and Natural Hazards CRC project whose primary objective o is to develop cost-effective strategies for mitigating damage to housing from severe windstorms across Australia. These evidence based strategies will be (a) tailored to both aid policy formulation and decision making in government and industry, and (b) provide guidelines detailing various options and benefits to homeowners and the building community for retrofitting typical at risk older houses in Australian communities.

}, author = {David Henderson and John Ginger} } @article {bnh-2356, title = {Improving the resilience of existing housing to severe wind events: Annual project report 2014-2015}, number = {143}, year = {2015}, month = {02/11/2015}, institution = {Bushfire and Natural Hazards CRC}, address = {Melbourne}, abstract = {

Damage investigations carried out by the Cyclone Testing Station (CTS) following severe wind storms have typically shown that Australian houses built prior to the mid-1980s do not offer the same level of performance and protection during windstorms as houses constructed to contemporary building standards. Given that these older houses will represent the bulk of the housing stock for many decades, practical structural upgrading solutions based on the latest research will make a significant improvement to housing performance and to the economic and social well-being of the community.

Structural retrofitting details exist for some forms of legacy housing but the uptake of these details is limited. There is also evidence that retrofitting details are not being included into houses requiring major repairs following severe storm events, thus missing the ideal opportunity to improve resilience of the house and community. Hence, the issues of retrofitting legacy housing, including feasibility and hindrances on take-up, etc., must be analysed.

The primary objective of this research is to develop cost-effective strategies for mitigating damage to housing from severe windstorms across Australia.\  These evidence-based strategies will be (a) tailored to aid policy formulation and decision making in government and industry, and (b) provide guidelines detailing various options and benefits to homeowners and the building community for retrofitting typical at-risk houses in Australian communities. Specific task items include:

{\textbullet} \  Categorize residential structures into types based on building features that influence windstorm vulnerability using Geoscience Australia and CTS survey data. From these, a suite will be selected to represent those contributing most to windstorm risk

{\textbullet} \  Involve end-users and stakeholders (i.e. homeowners, builders, regulators, insurers) to assess amendments and provide feedback on practicality and aesthetics of potential upgrading methods for a range of buildings. Cost effective strategies will be developed for key house types

{\textbullet} \  Vulnerability models will be developed for each retrofit strategy using survey data, the authors{\textquoteright} existing vulnerability models, and the NEXIS database of Australian housing characteristics. Case studies will be used to evaluate effectiveness of proposed retrofit solutions in risk reduction. Economic assessment using the same case studies will be used to promote uptake of practical retrofit options

}, issn = {143}, author = {Daniel Smith and David Henderson and John Ginger and Martin Wehner} } @article {bnh-1535, title = {Improving the Resilience of Existing Housing to Severe Wind Events Annual Report 2014}, year = {2015}, abstract = {

This is an annual report for the year 2013/14 for the Improving the Resilience of Existing Housing to Severe Winds project. The primary objective of this project is to develop cost-effective strategies for mitigating damage to housing from severe windstorms across Australia.

}, author = {David Henderson} } @conference {bnh-2092, title = {Investigation of damage: Brisbane 27 November 2014 sever storm event - non peer reviewed extended abstract}, booktitle = {Adelaide Conference 2015}, year = {2015}, address = {Adelaide, Australia}, abstract = {

Research proceedings from the Bushfire and Natural Hazards CRC \& AFAC Conference in Adelaide, 1-3 September 2015.\ 

}, author = {Korah Parackal and M. S. Mason and David Henderson and D. J. Smith and John Ginger} } @article {bnh-2508, title = {Modelling cyclone loss mitigation using claims analysis}, year = {2015}, abstract = {

This paper follows from a series of recent studies conducted by the authors and Suncorp Group Limited which analysed insurance claims from Tropical Cyclone (TC) Yasi (Queensland, 2011) to determine typical drivers of insured loss (i.e. roofing failures, etc.) for residential housing. Using the claims data from TC Yasi, the benefits of mitigation were broadly estimated by reducing claim values based on survey results from builders and assessors on expected loss reduction in properties with mitigation features. This information was provided to Urbis (project consultant to Suncorp) for cost-benefit analysis of the projected benefits of mitigation over the next 50 years in Queensland. In this paper, the claims manipulation approach to modelling loss mitigation is presented and the results for TC Yasi are briefly discussed.

}, author = {Daniel Smith and David Henderson and Lucy M Terza} }