Survey of Flood Damage to Buildings Uncertainties and Standardisations

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1 Survey of Flood Damage to Buildings Uncertainties and Standardisations by Professor David Proverbs Flood Research Group School of Engineering and the Built Environment University of Wolverhampton

2 Climate Change: UK Implications Experts predict that: Temperature will rise by 3 o C by 2100 (unprecedented warming rate) Mean sea levels will rise by around 25 cm by 2100 Heavy rain will be 4-5 times more common in 2050 than n at present 1 in 100 year flooding event today will become 1 in 20 year event by 2050 Regular and serious flooding will become a fact of life for many parts of the UK in years to come

3 UK Flooding Facts 2 million homes and 185,000 commercial properties worth over 215 billion 1.3 million hectares of agricultural land worth 7 billion 5 million people in England and Wales are at risk from flooding Autumn 2000 floods affected an estimated 10, homes across the country with the estimated cost of million The worst flooding in 1953 claimed 480 lives and caused damage valued at 5 5 billion Today, a similar flood could cause more deaths and over 20 billion insured losses

4 Assessment of Flood-Damaged Property A Literature Review Little consensus of opinion and ignorance of many factors regarding damage assessment procedures or optimal repair methods Prone to subjectivity and significant variance Existing guidance is mostly based on generalisation,, ad-hoc and simplistic Lack of knowledge regarding appropriate drying methods and their effectiveness Highlighted the need of definitive guidance on flood- damaged assessment and subsequent reinstatement works

5 Flood Damage Research Principle Aim: To generate benchmarks in respect of flood damage remedial works for typical domestic properties based on the opinions of experts

6 Flood Damage Research The following aspects were also investigated: The importance of flood characteristics when undertaking an assessment of flood damage, and sources of information or methods to determine each characteristic Methods and/or equipment employed to dry flood- damaged buildings Methods used to determine if a building is sufficiently dry for repair works to commence

7 Project Methodology Questionnaire survey designed to collect data regarding: Background information (details of employer, working area, job title and experience in assessing flood-damaged damaged properties) Perceived importance of flood characteristics and methods used in i practice to determine the characteristics Drying methods and their effectiveness (present and ideal) Methods used in practice to determine if a building is sufficiently dry (present and ideal) Repair strategies (present and ideal) and their performance (cost, time, quality and client satisfaction), based on common flood damage scenarios (floors, walls, doors and windows, utilities) presented in the form of digital photos taken from real footage of flood-damages damages properties

8 Project Methodology Example of flood damage scenario: An external wall of a flood-damaged damaged property has evidence of rising damp problem Respondents were asked to choose one from several repair strategy options provided Additionally, they were invited to add their own strategy if this was not listed

9 Project Methodology Questionnaire was distributed to: 1800 members of the RICS Residential Faculty Members of the Chartered Institute of Loss Adjusters via an invitation (in the form of leaflet) to participate in the survey Additionally, data were collected through online questionnaire in the project website. Overall, 289 completed questionnaires were received

10 Characteristics of the respondents Respondent organisations Estate agent/housing Association Consulting engineers Loss adjuster 59.7 Environmental Services 1.7 Damage repair specialist 6.3 Surveying consultancy practice 23.3 Architectural practice Local authority Insurance company Percentage of respondents

11 Characteristics of the respondents Operating regions of the respondents organisations North-West East Midlands South-East 48.9 Yorkshire and Humberside 12.7 Scotland 3.9 East Anglia West Midlands South-West 18.0 Wales The North Percentage of respondents

12 Characteristics of the respondents Respondents levels of experience in terms of number of years in assessing flood-damaged properties 30 Percentage of respondents Number of years in assessing flood-damaged properties

13 Perceptions of Flood Characteristics Perceived importance of flood characteristics Flood characteristics Mean Median Mode Rank Sewage and fasciae content Contaminant content Depth Duration Source Velocity

14 Experts Perceptions of Flood Characteristics Strong evidence of positive relationships between the importance of contaminant content, duration, source and depth of the floodwater, and the number of properties surveyed over the last 2, 5 and 10 years Experts with more experience consider these characteristics to be more important

15 Experts Perceptions of Flood Characteristics Findings of methods to determine flood characteristics: Flood damage assessors relied heavily on visual inspections and independent judgments Local information and/or witnesses were also important sources of information, particularly for determining the depth and duration of the flood Suggests that current assessment of flood-damaged damaged properties contains subjectivity and may therefore be prone to variation

16 Drying Methods Used in Practice Surveyors consider various methods to assist drying rather than focusing on a single dominant method. The most popular method involved making use of any existing heating systems (practical and timely). The most popular ideal drying method was to install temporary heating.

17 Drying Methods Used in Practice Property size (in terms of volume, area, number of rooms) was the most important factor to determine the number of dehumidifiers to be installed in a flood-damaged damaged property Some damage assessors would rely on experienced-based trial and error and generalisation of one dehumidifier per room or two per standard semidetached house Two-thirds of the respondents sealed off sections of the property to assist the drying procedure

18 Drying Methods Used in Practice A high degree of subjectivity was again found in determining the number of sections to be sealed off Lack of knowledge in regard to appropriate methods to determine dampness levels, and hence reliance on subjective methods (i.e. based on visual observation and allowing a number of days after the flood) These methods were perceived to be the least effective but ironically used quite extensively The most effective method perceived was calcium carbide moisture metres

19 Repair Strategies Used in Practice Most popular strategy is not necessarily the best solution in terms of cost, quality, time and satisfaction nor the benchmark for a particular scenario. However, most surveyors are satisfied that their current practice is the most appropriate solution The tendency is that any strategy which derives higher quality and/or satisfaction demands higher cost and vice versa There are few strategies which perform better in all aspects

20 Repair Strategies Used in Practice In some scenarios, cost is not the most important consideration Some respondents would recommend an alternative strategy than their present one The increased cost involved is the main reason for not employing strategies which delivered higher quality and satisfaction

21 On-going Research at the Flood Research Group EPSRC International Network of Experts on Flood Damage and Repair (refer to flyer) Impact of flooding / risk of flooding on residential property values and costs of insurance An investigation into the satisfaction levels of UK domestic property occupiers with respect to flood damage repair works

22 Acknowledgements We gratefully acknowledge the financial support provided by the sponsor of this research, Lloyds TSB Insurance; and also the support in kind provided by Rameses Associates and the RICS Foundation. We also wish to thank building surveyors and loss adjusters who participated in the questionnaire survey.

23 Selected list of relevant publications of the Flood Research Group Proverbs, D, Nicholas, J. and Holt, G.D. (2000) 'Surveying flood damage to domestic dwellings: The present state of knowledge', RICS Research Foundation Paper Series, Volume 3, Number 8. ISBN Nicholas, J., Holt, G. D., and Proverbs, D. (2001) Towards standardizing ardizing the assessment of flood damaged properties in the UK. Structural Survey, Volume 19, Number 4, pp ISSN X. 080X. Awards for Excellence 2002 most Outstanding Paper in the 2001 volume. Soetanto,, R. and Proverbs, D.G. (2004) Impact of flood characteristics on damage caused to UK domestic properties: the perceptions of building surveyors. Structural Survey Special Issue: Flooding: Implications for the Construction Industry. Guest Editor: D.Proverbs erbs,, Volume 22, No 2, ISBN Nicholas, Proverbs and Holt (2001) An Investigation Into Factors Influencing The Assessment Of UK Flood Damaged Domestic Properties,, in Proceedings of RICS COBRA 2001 Conference, Glasgow Caledonian University, 3 rd 5 th September, pp ISBN (2 vols.) Soetanto,, R., Proverbs, D.G. and Nicholas, J. (2002) Assessment of flood damage to domestic properties: surveyors perceptions of flood characteristics.. RICS COBRA Conference, Nottingham Trent University, 5-66 September 2002, pp ISBN COBRA 2002: Awarded the RICS Building Surveying Faculty Postgraduate Prize for Samwinga,, V. and Proverbs, D. (2003) ) Satisfaction Of Domestic Property Occupiers With Respect To Flood Damage Repair Works.. ARCOM Nineteenth Annual Conference, September 3-5, 3 University of Brighton, pp ISBN

24 Selected list of relevant publications of the Flood Research Group Soetanto,, R. and Proverbs, D.G. (2003) Benchmarks for the repair of Flood Damaged External Walls. Proceedings of the Royal Institution of Chartered Surveyors (RICS) COBRA Conference, University of Wolverhampton, 1 st to 2 nd September, pp ISBN Samwinga,, V., Homan, J. and Proverbs, D. (2004) Satisfaction issues in the reinstatement of flood damaged domestic property. 4th International Postgraduate Research Conference, Salford University, March 29 th -April 4 th, pp ISBN Samwinga,, V., Proverbs, D. and Homan, J. (2004) Exploring the experience of insured UK homeowners in flood disasters. International RICS Construction and Building Research Conference (COBRA) 2004, Leeds Metropolitan University, September ISBN Lamond,, J., Proverbs, D. and Antwi,, A. (2005) The effects of floods and floodplain designation on value of property: An analysis of past studies. The Second Scottish Conference for Postgraduate Researchers of the Built and Natural Environment (ProBE( ProBE),, th November 2005, Glasgow Caledonian University, Glasgow, pp Edited by Charles Egbu and Michael Tong. ISBN X Proverbs, D.G. and Soetanto,, R. (2004) Flood Damaged Property: A Guide to Repair. Blackwell Publishing. ISBN

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