@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-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} }