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Resilient Buildings: Informing
Maintenance for Long-term
Sustainability
Final Industry Report, Project 1.53
November 2018
Lam Pham | Palaneeswaran Ekambaram | Rodney Stewart | Oz Sahin
Edoardo Bertone | Juliana Flores | Guilherme Franklin de Oliveira
Copyright © SBEnrc 2018
This book has been peer reviewed
by independent reviewers.
Recommended Citation: Lam Pham, Palaneeswaran
Ekambaram, Rodney Stewart, Oz Sahin, Edoardo
Bertone, Juliana de Faria Correa Thompson
Flores and Guilherme Franklin de Oliveira (2018)
Resilient Buildings: Informing Maintenance
for Long-term Sustainability — Final Industry
Report. Sustainable Built Environment National
Research Centre (SBEnrc), Australia.
This Final Industry Report summarises research
carried out in SBEnrc Project 1.53 — Resilient
Buildings: Informing Maintenance for Long-term
Sustainability. The Project Research Report Parts
1-4 (available at https://sbenrc.com.au/research-
programs/1-53/) describes the research process
and outcomes in a more comprehensive manner.
The content of this publication may be used and
adapted to suit the professional requirements of
the user, with appropriate acknowledgement of the
Sustainable Built Environment National Research
Centre (SBEnrc) and the report’s authors. It may
be reproduced, stored in a retrieval system or
transmitted without the prior permission of the
publisher. All intellectual property in the ideas,
concepts and design for this publication belong
to the Australian Sustainable Built Environment
National Research Centre. The authors, the SBEnrc,
and its respective boards, stakeholders, ocers,
employees and agents make no representation or
warranty concerning the accuracy or completeness
of the information in this work. To the extent
permissible by law, the aforementioned persons
exclude all implied conditions or warranties and
disclaim all liability for any loss or damage or
other consequences howsoever arising from
the use of the information in this publication.
John V McCarthy AO
Chair
Sustainable Built Environment
National Research Centre
Dr Keith Hampson
Chief Executive Ocer
Sustainable Built Environment
National Research Centre
The Sustainable Built Environment National Research Centre (SBEnrc), the successor to
Australia’s Cooperative Research Centre (CRC) for Construction Innovation, is committed to
making a leading contribution to innovation across the Australian built environment industry.
We are dedicated to working collaboratively with industry and government to develop and
apply practical research outcomes that improve industry practice and enhance our nation’s
competitiveness.
We encourage you to draw on the results of this applied research to deliver tangible
outcomes for your operations. By working together, we can transform our industry and
community through enhanced and sustainable business processes, environmental
performance and productivity improvements.
Preface
3
This research has been developed with funding and
support provided by Australia’s Sustainable Built
Environment National Research Centre (SBEnrc) and
its partners.
Core Members of SBEnrc include Aurecon, BGC
Australia, Queensland Government, Government
of Western Australia, New South Wales Roads and
Maritime Services, New South Wales Land and
Housing Corporation, Curtin University, Grith
University and Swinburne University of Technology.
We are grateful for the contributions of the workshop
and interview participants and persons consulted from
various stakeholder organisations such as Australian
Windows Association, Australian Building Codes
Board (ABCB), Australasian Fire and Emergency
Services Authorities Council (AFAC), Commonwealth
Scientic and Industrial Research Organisation
(CSIRO), Department of Fire and Emergency
Services (DFES) – Western Australia, and Facilities
Management Association of Australia (FMA).
Acknowledgements
Core SBEnrc Members
Project Aliate
Project Steering Group
Graeme Newton, PSG Chair, Head, Cross River Rail
Delivery Authority (CRRDA), Brisbane
Lam Pham, Project Leader, Professor,
Swinburne University of Technology
Carl Barrett, Group Manager, Energy and
Environment, BGC Australia
Dan Gardiner, Energy and Environment Advisor,
BGC Australia
Sarah Mewett, Manager, Analytics and Market
Intelligence, Department of Communities, WA
Veronica Pannell, Policy and Research Ocer,
Department of Communities, WA
Carolyn Marshall, Principal Architect,
Building Management and Works, Department
of Finance, WA
Dean Wood, Principal Architect, Building
Management and Works, Department of Finance, WA
Rosemary Axon, Principal Architect, Department
of Housing and Public Works, QLD
Dean Luton, Senior Architect, Department of
Housing and Public Works, QLD
Jessica Dominguez, Senior Project Ocer, Service
Reforms, Land and Housing Corporation, NSW
Martin Nunez, GIS Project Manager, Property
Information, Land and Housing Corporation, NSW
Palaneeswaran Ekambaram, Associate Professor,
Swinburne University of Technology
Emad Gad, Professor, Swinburne University
of Technology
Rodney Stewart, Professor, Grith University
4
Resilience of buildings is a national objective in disaster mitigation. Often, maintenance is
a missing link to improving the resilience of buildings in extreme events. The performance
of the buildings decreases over time and without eective maintenance, their vulnerabilities
to extreme events will increase. This SBEnrc Project 1.53 Resilient Buildings: Informing
Maintenance for Long-term Sustainability aimed to examine the role of maintenance in
making buildings more resilient to the extreme weather impacts of bushres, oods and
water ingress from cyclones and high winds. This project focused mainly on low-rise public
buildings and the use of technical knowledge to inform policy and practice. The methodology
included literature reviews, workshops, interviews and industry consultations looking for
gaps in current policy and practice. The Project Research Report (Parts 1-4) provides further
details on each aspect of the research and supporting references.
The key recommendations from this SBEnrc Project P1.53 are:
1. A maintenance schedule for building assets should be provided as part of the design for
durability.
2. A maintenance manual for each building should be made available for the people
responsible for its maintenance.
3. Accurate as-built documentation should be made available for maintenance purposes.
4. Routine maintenance inspections should be used to detect prevailing and new emerging
risks to building resilience.
5. An appropriate procurement framework for responsive maintenance should be developed.
6. ‘Build back better’ for sustainable resilience against natural hazards.
7. Establish maintenance responsibilities for whole-of-life value and sustainability.
8. Develop smart infrastructure with advanced digital integration for ecient maintenance and
eective resilience.
The project outcomes of key recommendations and implementation strategies will be useful
to building owners, governments and industry stakeholders. The creation of a ‘Framework
for specifying building maintenance’ is recommended, from which individual building
maintenance manuals can be compiled.
Executive Summary
5
IntroductionContents
Introduction 6
Maintenance of buildings
– a key post-construction agenda 8
Maintenance and resilience
of buildings for bushre risks 9
Maintenance and resilience
of buildings for ood vulnerabilities 12
Maintenance prevention strategy
to mitigate wind-driven rainwater
ingress through windows and external
glazed doors in social housing 18
Recommendations from
SBEnrc Project 1.53 24
Natural disaster hazards are signicant risks in Australia.
The cumulative value of total losses from natural disasters
for the period 1967-2013 was AUD $171.5 billion (2013
price equivalent), in which the cost of death and injuries
was $15.3 billion1. Specically, the proportions of natural
disaster losses in Australia during this 46-year period were:
(i) 32% from storms, (ii) 28% from oods,
(iii) 19% from cyclones, (iv) 17% from bushres, and
(v) 4% from other extreme events (such as earthquakes).
Losses across Australian States and Territories and
dierent event types are shown in Figure 1.
This SBEnrc project, 1.53 Resilient Buildings: Informing
Maintenance for Long-term Sustainability, aimed to
examine the role of maintenance in making low-rise
buildings more resilient to the extreme weather events
of cyclones/high winds, bushres and natural oods,
using technical knowledge to identify gaps and inform
policy and practice. The research methodology included
focused literature reviews, brainstorming discussions
with the research teams and the project steering group,
interviews and workshops with industry practitioners and
correspondence/consultations with project aliates and
other stakeholders. The Project Research Report (Parts
1-4) provides further details and references for each aspect
of the research2.
1 The information on losses for the 46-year period (1967 to 2013) is extracted from: Handmer, J., Ladds, M.
and Magee, L. (2016) Disasater Losses from Natural Hazards in Australia, 1967-2013.
2 SBEnrc Project 1.53 webpage: https://sbenrc.com.au/research-programs/1-53/
6
Figure 1. The attribution of total disaster losses to extreme events in Australia
– 1967 to 2013
40,000
30,000
20,000
10,000
0
NSW NT TASQLD WA ACTVIC SA Other
2013 Dollars in $millions
Australian State/Territory
Reported cost
Insured cost
4%
32%
28%
17%
19%
Storm
Flood
Cyclone
Bushre
Other
7
Maintenance of buildings –
a key post-construction agenda
Maintenance activities are undertaken while the buildings
are in use to keep the building performance at a level
safe and acceptable to the users. Maintenance activities
include periodic and post-event inspections, repairs,
replacements, refurbishments and retrots. Resilience
of a building is its ability to survive and be restored after
extreme events. Maintenance should be considered as
part of the building’s durability performance-based design.
According to ISO 15928-3:2015, a maintenance schedule is
a key component in the description of structural durability
performance. Dierent strategies for maintenance may
be adopted, depending on how the building is designed
for durability. Maintenance of performance-based design
is problematical; for example, the replacement of non-
standard and novel products.
The Australian National Construction Code (NCC) currently
contains no maintenance provisions as these are principally
deemed as post-construction activities. This is a policy
decision from the States and Territories (S&T). Maintenance
is considered as a S&T responsibility in Australia. All S&Ts
have developed their guidelines for the maintenance of
essential safety measures. Maintenance for habitability
aspects (e.g. aesthetic and comfort) are generally carried
out by the building owners or facility/property managers
or occupants. Systems and arrangements for preventative
maintenance targeting long-term resilience and mitigation
are at an infancy stage in many client organisations. Also,
in most cases there is generally no maintenance manual for
the buildings. While there is considerable information on
building maintenance, there is no single source of reference
to inform the users, particularly on condition assessment or
preventive maintenance for natural disasters such as high
winds/cyclones, oods and bushres.
In 2018, Shergold and Weir reported to the Australian
Building Ministers Forum on the eectiveness of
compliance and enforcement of the Australian building
regulatory system3. As per their recommendations, a
building manual in digital format is required to be provided
which should have: (i) as-built construction documentation;
(ii) maintenance requirements; (iii) assumptions made in
performance solution; (iv) building product information; and
(v) conditions of use. According to the British Research
Establishment (BRE) report4, only 32% of the total building
repair cost is spent on making the repairs and the remaining
68% is usually spent on: (i) producing tender documents;
(ii) comparing prices (where not covered by a schedule of
rates); (iii) placing orders; (iv) checking work in progress;
(v) checking work on completion; (v) measuring completed
work quantities; (vi) raising invoices; (vii) validating invoices;
and (viii) negotiating discrepancies. Ecient and more
resilient building stock in the public sector could be
achieved through eective procurement arrangements
of responsive maintenance with relevant partnering and
alliance frameworks.
3 Shergold, P. and Weir, B. (2018). Building Condence – Improving the eectiveness of compliance and enforcement systems for
building construction industry across Australia – February 2018; https://www.industry.gov.au/sites/g/les/net3906/f/July%202018/
document/pdf/building_ministers_forum_expert_assessment_-_building_condence.pdf
4 Prior, J.J. and Nowak, F. (2005). Repair it with eective partnering – Guide to contractual relationships for cost eective responsive
maintenance, British Research Establishment (BRE) report.
8
Maintenance and resilience
of buildings for bushfire risks
Bushres are unplanned res in vegetation areas such as
forest, woodland, shrub land, and grassland. In Australia,
bushre risks are critical in dry summer seasons as there
is a greater potential for spread of re from hazards such
as burning embers, radiant heat and direct/indirect ame
contact. Bushre occurrence is a recurrent concern in
several regions and often results in property damage/
destruction and sometimes in injuries/fatalities.
Bushfire attack mechanisms
and building losses
In the event of a bushre, a building could be ignited
by a range of mechanisms:
• Direct exposure to ames from a bushre – where there
is an insucient set-back distance between buildings
and the dominant bushre vegetation (DBV) such avs
forest, scrub, crops or a combination.
• Direct ember attack – which is the most common cause
of ignition and loss of buildings due to bushres. Ember
density is directly proportional to the distance between
building stock and DBV. Under extreme circumstances,
embers can travel a long distance (1 to 10 km). Short
distance embers (within 1 km of a re front) are often
found in prolic numbers and tend to have greater impact.
Typically this mechanism is responsible for over 90% of
ignitions leading to building loss in an urban environment.
• Radiation due to a re associated with DBV – in which
(i) the building vulnerabilities are dependent on radiation
exposure and duration of exposure; (ii) the radiation
experienced by an object is a function of the temperature
of radiant heat source, its geometry and orientation and
distance between the object and the radiator; and (iii) the
intensity of received radiation is a function of set-back
distance, type of vegetation and the ame height.
• Secondary radiation – such as from re associated
with an adjacent building, object or vegetation. If a
neighbouring building or object catches re, then the
duration of burning may be between 15 -20 minutes
which is signicantly longer than the duration of a
passing ame front. The resulting radiation may be
signicant depending on the separation distance
between this building/object and the subject building.
Assisted by wind, burning embers, radiant heat and ames
may (i) enter the building and directly ignite its contents,
(ii) enter the building envelope and ignite combustible
elements within the cavities of the building envelope and
later ignite the building contents, (iii) cause the building
façade or façade elements to break, distort or yield, leading
to one of the above processes, and/or (iv) ignite the façade
of the building leading to one of the above processes. The
combined eects of wind and re may lead to structural
failure well below the ultimate design wind speed, but this
has not been investigated in detail anywhere.
9
Location Hazard vs. Property Bushfire Resistance
= Building Vulnerability
Building Vulnerability vs. Occupant Vulnerability
= Bushfire Risk
Figure 2. Example of a Bushre Risk Assessment
Bushfire risk assessment
A building’s vulnerability for bushre risk is dependent on
its location and resistance capacity. Several parameters
contribute to the location hazard levels and the Bushre
Attack Level assessment procedure of AS3959 is a fair
description of the site hazard characteristics for bushre
risks. Property bushre resistance characteristics depend
on the building itself and the surrounding elements such as
gardens, fences and combustible materials.
Occupant vulnerability is a key factor in bushre
emergencies. While maintenance can contribute to
lowering the risk of ignition for all buildings within the
designated bushre prone areas, ‘high risk’ buildings,
such as hospitals, may need additional consideration such
as access, re-ghting facilities, and evacuation route.
Seeking advice from bushre experts is recommended for
complex cases and high risk categories. An example of a
Bushre Risk Assessment is given in Figure 2.
Location
Hazard
Property Bushre Resistance
High (H) Medium (M) Low (L)
High (H) M H H
Medium (M) L M H
Low (L) L L M
Building
Vulnerability
Occupant Vulnerability
Low (L) Medium (M) High (H)
High (H) M H H
Medium (M) L M H
Low (L) L L M
Building regulations and standards
in Australia
The performance requirements for construction in
designated bushre prone areas (dened in States and
Territories Regulations) are in Volumes 1 and 2 of the
National Construction Code (NCC). The specic clause
from the NCC is: ‘A building that is constructed in a
designated bushre prone area must, to the degree
necessary, be designed and constructed to reduce the risk
of ignition from a bushre, appropriate to: (a) potential for
ignition caused by burning embers, radiant heat or ame
generated by a bushre; and (b) intensity of the bushre
attack on the building.’
The draft NCC 2019 introduces a systematic verication
method based on an ignition probability threshold of 10%
under the inuence of appropriate bushre design action.
By considering the asset perspective and occupancy type,
it clusters with importance level (IL) 1 to 4 for determining
the bushre design action assigns an annual probability
of exceedance to each IL – e.g. IL = 2 for a small motel or
boarding house; IL = 3 for a large hotel; IL = 4 for an aged
care building.
Australian Standard AS3959 has outlined a method of
determining the Bushre Attack Level for a site, with a
step-by-step procedure including factors such as climate,
slope of ground and vegetation variations. In addition,
a set of deemed-to-satisfy provisions are available in
AS3959 (e.g. for Class 1, 2 and 3 buildings) and in The
National Association of Steel-framed Housing (NASH)
Standard (e.g. for Class 1 and 10a).
10
11
Maintenance for improved bushfire
resilience of buildings
Maintenance has a key role in reducing the risk of ignition
due to ember actions. Gaps around the edges of the roof or
along the roof’s ridge, eaves and roof line provide pathways
for the entry of embers into a roof space. The same is
true with respect to ventilation openings into spaces
below suspended oors, if there are combustible surfaces
against which embers can accumulate. Open vents can
also allow the entry of embers into the interior space, and
evaporative coolers, due to their combustible lters, are
susceptible to ember attack, especially if they are not
operating at the time of the re and the lters are dry. The
accumulation of embers against exterior combustible
surfaces can also result in ignition. Gaps greater than 3 mm
are sucient to allow the entry of some types of ember.
Hence the standard requirement to have vents and weep
holes screened with metal mesh with a maximum aperture
of 2 mm unless they have an aperture less than 3 mm.
The external facade shall be prevented from having gaps
greater than 3 mm. Doors and windows in bushre risk
zones are required to have a protective metal mesh with
maximum aperture of 2 mm. A set of useful inspection
points consolidated from the literature follows:
• External ignition points such as timber decks, eave fascia
boards and/or gutters, timber window frames, timber
stairs, timber door frames, red cedar cladding, gapped
board around stumps, exposed timber beams, timber
wall frames, doormats, fabric veranda roofs, timber
shingle roofs, plastic roof panels, veranda/pergola,
timber framing behind air conditioning units, bitumen roof
membranes, canvas awnings and weather boards.
• Ember entry points such as door jams, windows that
are not tight-t, ues and chimneys, gaps in roong or
ooring systems and gaps in building facades
• Ember accumulation points such as re-entrant corners,
roof valleys, gutters, unprotected sub-oor areas, wall/
roof cavities, under decks and between decking boards
above bearers, door thresholds and window frames.
Recommendations to enhance
maintenance and resilience
of buildings for bushfires
1. All buildings in designated bushre prone areas
should be maintained to reduce the risk of ignition
due to ember attack.
2. An integrated database of critical maintenance items
for buildings and their surrounding areas should be
established. In addition, a list of key maintenance
items for bushre risks should be compiled for each
individual building.
3. For high risk buildings, relevant bushre experts should
be consulted for more accurate assessments and
suitable measures to lower the risks for the building
and its occupants.
11
Floods are common and recurrent extreme events in all
States and Territories in Australia. The Bushre and Natural
Hazard Cooperative Research Centre has reported that
oods are the most nancially costly and the second
deadliest natural hazard in Australia. The complexities
and uncertainties of ood risks are diverse in Australia,
including the eects of variable rainfall, climate change
and cyclones, across more than eight climatic zones5.
Flood types impacting buildings include:
• Fluvial (river) ooding – when a watercourse swells
due to heavy and/or prolonged rainfall.
• Pluvial ooding – when substantial water pools
on the ground or is unable to drain away.
• Closed-basin ooding – when a closed body
of water receives excessive runo.
• Flash ooding – when a rapid overland ow
of water occurs due to high intensity rainfall.
• Sewer (drainage) ooding – when pipes and sewers
are not adequate to cope with rainfall.
• Coastal ooding – when inundation of land occurs
in coastal regions due to storms or high tides.
• Groundwater ooding – when ground water levels
rise above the surface.
Flood impacts and building damage
Natural oods and water ingress vulnerabilities from
high winds such as severe storms and cyclones cause
signicant damage to low-rise buildings in Australia. The
tangible impacts are mainly acute/short-term damage and
chronic/long-term deterioration. Intangible impacts include
the stress of dealing with builders/repairers/insurers,
emotional losses and fear of resilience for future oods.
Floods can damage structures and non-structural
components of buildings due to a range and combination
of ood forces/actions including:
• Hydrostatic forces and resultant actions
– Lateral pressure; e.g. when water rises on one side
of a structure, such as a wall
– Capillary rise; e.g. when capillary action causes
upward movement of dampness/wetness
• Hydrodynamic forces and resultant actions
– Lateral pressure caused by water owing
around a building
– Suction by localised changes in velocity/pressure;
e.g. around corners and through gaps
– Turbulence due to irregular uctuations in velocity
– Breaking and non-breaking waves
• Buoyancy and resultant actions; the whole building
or its components oat or cause other damage
• Impact forces of oating debris and resultant actions
– Static actions; e.g. sediment accumulation inside
or outside the building
– Dynamic actions; including concentrated and
distributed forces
– Erosion actions; e.g. associated with dragged
soils/gravels/other debris
• Non-physical actions; such as chemical (e.g. rust and
corrosion of reinforcement) and biological elements
(e.g. mould by singular/ multicellular fungi and timber
decay)
5 The Australian Building Codes Board (ABCB) mapped the states and territories of Australia into
eight climate zones for the National Construction Code - i.e. (1) High humidity summer, warm winter;
(2) warm humid summer, mild winter; (3): hot dry summer, warm winter; (4) hot dry summer, cool
winter; (5) warm temperate; (6) mild temperate; (7) cool temperate; and (8) alpine.
Maintenance and resilience of
buildings for flood vulnerabilities
The extent and duration of ood exposure as well as the
condition of a building can sway the risk of damage. Typical
types of building damage from ood impacts include:
• Damage to foundations from geotechnical/soil failures.
• Damage to walls and building components; e.g. cracks,
dampness, warping, aking and lifting.
• Damage to oors; e.g. lifting of ooring, decay of joists,
springy boards, sub-oor moisture.
• Damage to utilities and non-structural components;
e.g. HVAC (heating, ventilation and air conditioning),
plumbing, electrical and mechanical systems.
Multi-hazard occurrences can enhance the risk levels;
for example, ood after cyclone/windstorm, ood after
ood, ood after re, ood after mudow and ood after
a hailstorm. Climate change eects may further increase
ood occurrences and associated risks. Increased demand
for new housing and non-residential buildings may increase
pressures to build in areas at risk to oods.
Figure 3 illustrates considerations in enhancing building
resilience to ood risks.
Figure 3. Enhancing building resilience to ood risks
• Parameters and benchmarks
• Information and databases
• Planning priorities
• Policies and governance
• Regulatory and
non-regulatory
responsibilities
Design for
maintenance
against ood
vulnerabilities
Maintenance
for ood
resilience
• Avoidance of
ood impacts
• Flood resistance
• Flood resilience
• Maintainability
and resilience
Planning and
governance for
preventative
mitigation
Sustainable
smart integration
and intelligent
systems
• Manuals and guidelines
• Lifecycle cost-based
decision models
and integrated asset
management framework
• Smart systems with BIM,
block-chain and Articial Intelligence
• Inspections and audits
• Safety evaluation
and checklists
• Routine maintenance
• Predictive maintenance
• Retrotting and build
back better
13
Planning and governance for preventive
mitigation
Useful parameters and benchmarks for planning buildings
resilient to ood hazards include: Annual Exceedance
Probability, Australian Height Datum, Probable Maximum
Flood, Dened Flood Event and Flood Planning Level.
References for planning and estimating riverine/coastal
ood vulnerabilities include the HAZUS ood technical
manual6. Additional benchmarking references for resilience
planning include the European Union Floods Directive,
UK Environment Agency report on National Flood and
Coastal Erosion Risk Management Strategy, UK House of
Commons reports on Future Flood Prevention7 and Flood
and Water Management Act 20108, and the USA Federal
Emergency Management Agency Policy Standards for
Floor Risk Analysis and Mapping.
Design for maintenance against flood
vulnerabilities
Design strategies for avoiding ood impacts on buildings
include: (i) siting, site layout and elevating land;
(ii) preventive landscaping and surrounding improvements;
(iii) drainage and soak-away systems; (iv) impermeable
boundary walls; (v) raising the lowest oor level of a building
with a threshold height above the likely design ood level.
Designing for maintainability will enhance the resistance and
resilience of buildings against ood risks. Some noteworthy
points consolidated from the recent literature include:
• Building design in ood hazard areas should conform
to requirements and guidelines such as ABCB9 and
ASCE/SCI 24-1410.
• It will be valuable to consider performance-based ood
design in accordance with standards and guidelines
such as ASCE/ SEI 24-05, FEMA 543, FEMA P798 and
FEMA P 424.
• Roof drainage design should consider the eects of
duration, intensity and frequency of rainfall, and design
rain loads and secondary roof drain data.
• Primary drainage systems shall be designed for a
rainfall intensity equal to or greater than the 60-min
duration/100-year return period (frequency) storm
(ASCE7-16).
• The 2015 International Plumbing Code requires the
use of 100-year return period/60-minute duration for
the design of both the primary drainage system and
the secondary drainage system. From a structural
engineering standpoint, the critical duration for most
roof geometries (the duration which maximises the
hydraulic head) is closer to 15 minutes than 6011.
6 FEMA (2011). Multi-hazard loss estimation methodology ood model Hazus®-MH 2.1 Technical Manual. Federal Emergency Management Agency, Washington, DC, USA.
7 HC (2017a). Future ood prevention: Government’s response to the Committee’s Second Report of Session 2016-17. House of Commons (HC) – Environment, Food and Rural
Aairs Committee, UK.
8 HC (2017b). Post-legislative scrutiny: Flood and Water Management Act 2010. House of Commons (HC) – Environment, Food and Rural Aairs Committee, UK.
9 ABCB (2012a). Construction of buildings in ood hazard areas, Version 2012-2, Australian Building Codes Board (ABCB), Australia; ABCB (2012b). Standard for construction of
buildings in ood hazard areas 2012 – Australian Building Codes Board (ABCB), Australia.
10 ASCE (2014). Flood resistant design and construction, ASCE Standard ASCE/SCI 24-14. American Society of Civil Engineers (ASCE), USA.
11 Chock, G., Ghosh, S.K., O’Rourke, M., and Staord, T.E. 2018. Signicant changes to the minimum design load provisions of ASCE 7-16, ASCE Press.
14
12 Chock, G., Ghosh, S.K., O’Rourke, M., and Staord, T.E. 2018. Signicant changes to the minimum design load provisions of ASCE 7-16, ASCE Press.
13 FEMA (2014). Homeowner’s guide to retrotting - six ways to protect your home from ooding, FEMA P-312: 3rd Edition, Federal Emergency Management Agency, Washington, DC, USA.
14 Useful reports include:
ATC (2004). Field manual: safety evaluation of buildings after windstorms and oods, ATC-45, Applied Technology Council, California, USA.
Bravery, A.F., Berry, R.W., Carey, J.K., Cooper, D.E. (2003). Recognising wood rot and insect damage in buildings, BR 453, British Research Establishment, UK.
BRE (1997a). Repairing ood damage: immediate action, Good Repair Guide 11 – Part 1, British Research Establishment, UK.
BRE (1997b). Repairing ood damage: ground oors and basements, Good Repair Guide 11 – Part 2, British Research Establishment, UK.
BRE (1997c). Repairing ood damage: foundations and walls, Good Repair Guide 11 – Part 3, British Research Establishment, UK.
BRE (1997d). Repairing ood damage: services, secondary elements, nishes, ttings, Good Repair Guide 11 – Part 4, British Research Establishment, UK.
BRE (2006). Repairing ooded buildings – an insurance industry guide to investigation and repair. Flood Repairs Forum, BRE Press,
British Research Establishment, UK.
• Each portion of a roof shall be designed to sustain
the load of all rainwater that will accumulate on it,
if the primary drainage system is blocked, plus the
uniform load caused by water that rises above the
inlet of the secondary drainage system at its design
ow (ASCE7-16).
• If the secondary drainage systems contain drain lines,
such lines and their point of discharge shall be separate
from the primary lines. The total head corresponding
to the design ow rate for the specied drains shall be
based on hydraulic test data12.
• Where a roof drain is installed in a sump pan located
below the adjoining roof surface, reductions in hydraulic
head and rain load on the adjoining roof should only
be credited when based on hydraulic analysis from a
qualied plumbing engineer. (ASCE 7-16)
• As water accumulates, roof deection allows additional
water ows. If the structure does not possess enough
stiness to resist this, failure by localised overloading
may result (ASCE 7-16).
• For existing buildings in a high-risk category, suitable
retrotting and design improvements should be adopted,
including elevation, relocation, ood proong and
barriers13
Maintenance for flood resilience
Factors inuencing building maintenance for ood
resilience include: type of material and construction; age
of the building; design and height; attached equipment,
annexures and non-structural/utility xtures; inuence of
regulatory policies and regimes; condition of the building;
current and intended purpose; documentation (e.g. format,
detail, quality); location and extreme event exposure;
social factors; economic factors (e.g. lifecycle costs);
safety and health aspects; environmental and energy/
resource aspects; materials, including spares; workforce
(e.g. availability, cost, knowledge and skills, workmanship,
integrity/trust). Repairing and maintaining ood-damaged
buildings is generally a reactive maintenance strategy.
Safety evaluation is a critical requirement before
repairing ood damage. Establishing inspection contexts
and checklist items would be relevant for proactive
maintenance of buildings for ood resilience14.
15
The literature review, brainstorming discussions and
consultations with industry partners and stakeholders
associated with this research revealed the following
key points:
• Routine inspection and maintenance for ood resilience
of buildings could be a shared responsibility at
appropriate levels relevant to all related parties.
• Developing maintenance manuals for ood resilience
of buildings and a library/knowledge portal of
maintenance checklists would be useful.
• Routine maintenance could target value procurements
with performance specications.
• Standardisation and certication of ood resilience
materials and ood protection products, would enhance
the reliability of maintenance and the eectiveness of
inspections.
• Education and training across the maintenance
supply chain (e.g. repairers) is needed.
Sustainable smart integration and
intelligent systems
Predictive maintenance can yield the best value and
sustainable resilience of buildings against natural
hazards such as oods. However, developing predictive
maintenance systems for practical use requires signicant
quality datasets of independent and dependent parameters
and variables of building stock maintenance. It would be
useful to link predictive models with integrated databases
of building assets with ‘as built’ information, condition
assessment (periodical and post-ood) and cost data
(maintenance, repair/retrot, lifecycle). The maintenance
decisions for ood hazards need to be rationalised through
integration of building information modelling (BIM), discrete
and real-time monitoring frameworks, advanced data
analytics and articial intelligence (AI) including machine
learning and deep learning systems.
16
Recommendations to
enhance maintenance and
resilience of buildings for
flood risks
1. All properties (including buildings and landscaping)
in ood prone areas should be maintained through
continuous monitoring and routine maintenance of
critical components.
2. Maintenance checklists of critical components for
the properties should be developed and integrated
with appropriate databases and systems for routine/
continuous condition monitoring and maintenance
decisions for ood resilience. The checklist should
cover all building structural elements, nishes, utilities
and non-structural xtures and landscaping within
the property.
3. Strict regulatory controls for building permits and
‘mature’ governance of maintenance for ood resilience
need to be developed.
4. All new designs should include responsible design
for maintainability embracing ood resistance and/
or ood resilience aspects. Responsive construction/
maintenance should be considered, embracing relevant
ood resilient technologies and materials in new
constructions and retrotting of existing constructions
for resilience.
5. Flood resilience planning agendas should be
developed for new development and maintaining
existing building assets.
6. A ‘smart’ systems approach with development of
maintenance manuals, smart systems and integrated
databases linked with building information and
lifecycle cost-based predictive/decision-support models
is required for futureproong resilience for
ood vulnerabilities.
7. As a non-mandatory arrangement for foolproof ood
resilience, certications for the maintenance supply
chain and ood resilience products/materials could
be considered.
17
The building envelope consists of various elements that
have to work together in order to protect the structure
against rain, wind, sleet and snow. In coastal cities and
towns in northern Australia, windows and external glazed
doors in buildings are particularly vulnerable to recurrent
serviceability failure caused by wind-driven rain during
cyclone events. Maintenance prevention strategies are
particularly important for government infrastructure and
building assets, since government is responsible for the
lifecycle maintenance of these. Maintenance prevention
strategies at the design, construction and inspection
stage of building procurement are the missing links to
improving resilience.
To develop a maintenance prevention strategy, rst a
literature review identied the failure modes of residential
buildings from cyclones and high winds. Subsequent data
collection included workshops and phone interviews with
design and construction professionals from manufacturing
and building rms, inspection rms and window installers,
as well as government. Thematic analysis of the workshops
and interviews identied a number of contributing factors
to the susceptibility for wind-driven rainwater ingress
through windows and external glazed doors in social
housing.
The research team also explored the standard of design
and as-constructed documentation, installation quality,
inspections regimes, Australian standards, and the
knowledge and training of window installers. The ndings
indicated that the current glazing process is sometimes
of insucient quality, resulting in recurrent repairs and
the overall lower quality of the construction. There is little
opportunity for government representatives to inspect
and assure work quality with the current standard of
documentation and during the preparation and installation
currently provided.
Maintenance prevention strategy to mitigate
wind-driven rainwater ingress through windows
and external glazed doors in social housing
Figure 4. Schematic quality assurance process during design
and construction of openings (windows and external glazed doors)
Construction
documentation
Contract
documentation
AC grade AC
OC
IQF
Preparation and installation
procedure
1 2
7 4
6
5
3
Core recommendations for prevention
strategies to mitigate wind-driven water
ingress
Seven core recommendations were developed:
(1) construction documentation (including
drawings and specications) (CD);
(2) contract documentation;
(3) preparation and installation procedure;
(4) auditing checklist (AC);
(5) installation quality form (IQF);
(6) openings certicate (OC);
(7) auditing checklist grade (AC grade).
19
Quality assurance process
using a social housing example
1. Construction documentation:
Social housing projects are often procured through
‘Construction only’ or ‘Design and Construction’
processes. The recommended quality assurance
process (Figure 4), has to adapt the order of items
1 and 2 according to these processes. For ’Design
and Construction‘, Contract documentation is before
Construction documentation, but for ’Construction
only‘, the process is reversed. Research indicated
that the move towards ’Design and Construction’
procurement has resulted in poorer quality design
and as-constructed information being produced by
contractors. The industry workshops revealed the need
for: (a) improved documentation and (b) providing more
specic information on detailed requirements from the
contractor within the tender documents.
For ‘Design and Construction’ arrangements, it is
recommended that either: (a) that process be limited to
projects where detailed documentation is not required;
or (b) the building contractor be required to provide fully
detailed construction documentation and specications
for the documentation stage and for as-constructed
records on handover of the project.
For ‘Construction Only’ projects: (i) the client should
ensure that fully detailed construction documentation
and specications are provided in the documentation
stage; and (ii) the builder is required to provide
as-constructed records on handover of the project
including detailed design documentation and
specications to describe the installation of windows
and external glazed doors. Specically, thorough
construction documents for windows and glazed door
openings are required for the buildings in wind regions C
(ultimate design wind speed 232.2 kilometers/hour) and
D (ultimate design wind speed 318.8 kilometers/ hour)
as per the Australian Standards AS/NZS 1170:2:2002.
The design specications for construction and
maintenance should cover: (a) durability and compatible
sealants; (b) preparing the substrate; (c) preparing the
opening with appropriate membrane system; (d) curing;
(e) head, side angle ashing, sub-sill and dam ends;
(f) ashings, drip moulds, storm moulds and trims; (g)
fasteners; and (h) storm shutters.
2. Contract documentation:
The tendering process should include the recommended
quality assurance process within the contract for all
forms of procurement. The contract requires agreement
between both the client and contractor. The contract
should describe a quality assurance process relating to
the preparation and installation of windows and external
glazed doors in an eort to increase quality and direct
liability in the construction phase. The contract should
include preparation and installation procedures for
windows and external glazed doors as well as IQF, AC,
OC and AC grade. This recommendation should apply
to all contract types; i.e. both Construction contracts,
and Design & Construct contracts.
20
3. Preparation and installation procedure:
The preparation and installation procedure of windows
and external glazed doors to masonry openings is
detailed in two stages as shown below, with further
detail in the Project Research Report Part 4.
Stage 1 – Openings preparation
(i) Ensure all primer, waterproong membrane and
sealants are compatible before installation.
(ii) Prepare the substrate in accordance with AS
4654.2 and Australian Window Association to
provide appropriate fall as per design (minimum
15 degrees as per AWA).
(iii) Ensure opening is clean, dry and free from debris.
(iv) Provide a continuous water-stop throughout the
perimeter of the opening.
(v) Prepare opening with appropriate primer and
waterproong membrane system in accordance
with AS 4654.2. Multiple layers of membrane
should be applied to ensure membrane is free from
any holes or gaps that will allow water to penetrate
the substrate. Ensure membrane has no gaps
and extends at least 200 mm past the opening.
(vi) Components of membrane systems shall be cured
as per manufacturer specications. Curing times
between applied membrane coatings should be
taken into account.
(vii) Install appropriate specied sub-sill, angled metal
dam ends, head drip moulds and side angles,
noting that the head-sill, side angle and ashings
must be directed to ow into the sub-sill without
any obstructions and the back and end dams
provide additional water-stop.
(viii) Ensure approved primer and sealant is used for a
water-tight seal and appropriate corrosion resistant
fasteners are used as per specied wind load or
engineer’s specications. Fasteners must be over
and under-sealed to prevent moisture penetrating
the opening. Allow appropriate clearances for
thermal expansion and free owing drainage.
Stage 2 – Openings installation
(i) Ensure the correct window and door specications
for terrain category and building height .
(ii) Ensure weep holes are free from debris and are free
owing.
(iii) Install window and door and frame to the opening
as per manufactures specications.
(iv) Ensure appropriate specied ashings, mouldings
and trims are installed to ensure the prevention of
water ingress.
(v) Storm shutters and awnings are to be installed as
per manufactures specications.
21
15 Build Back Better in recovery, rehabilitation and reconstruction (2017): https://www.unisdr.org/les/53213_bbb.pdf
4. Auditing Checklist (AC):
The Auditing Checklist for a building has to be completed
during the inspection of windows or external glazed
doors by superintendents. The objective is to check
they are installed adequately and note a relevant grade
(i.e. Satisfactory/Unsatisfactory). Another objective
is to place responsibility and liability on contractors
and superintendents. The AC is to be completed by
the superintendent, accompanied by the supervisor
responsible for the activity. The AC is completed at two
stages: (i) upon completion of the opening membrane
and ashing system; and (ii) on completion of the glazing
installation. The superintendent should give reasonable
notice (e.g. 2 weeks) to the primary contractor before
performing the AC. A building certier may also inspect
building work at any time, whether or not the certier
is given a notice for an AC for the work. The number of
windows and external glazed doors to be checked on
site will be a minimum of 25%, identied by a unique
identication tag or sticker. An Installation Quality Form
(IQF) completed by the primary contractor will display
a unique sicker to ensure the appropriate number of
inspections occur evenly over all levels of the building.
The frequency will vary according to the site schedule and
each opening will have its own independent check list.
Figure 5. Auditing Checklist (AC)
22
5. Installation Quality Form (IQF):
The primary contractor is responsible for completing
the IQF in conjunction with relevant installation
documentation (e.g. in Queensland – Form 16) and
providing this to the superintendent. For visual evidence,
the IQF should include photographic documentation
of each completed stage of the installation. It is
recommended that (a) the number of windows and
external glazed doors documented is a minimum of 25%;
and (b) an indicator tag/ sticker is allocated once the
opening has been documented. The objective of the IQF
is to (a) check whether the external openings are installed
satisfactorily and (b) raise liability and responsibility for
contractors/builders in placing sucient attention to
windows and external glazed doors as a building element
that is signicantly important to the building envelope.
6. OpeningsCerticate(OC):
Once the AC and IQF have been completed, the
superintendent provides the Openings Certicate (OC)
to the contractor. The aim of the OC is similar to that of
the AC and the IQF, in that it documents responsibility
for the information provided from both the contractor
and superintendent. For all building projects located in
Wind Regions C and D, the AC and IQF together will
have to document 50% of the openings of the project.
Also, the approach could be considered for all building
projects where vulnerability to wind-driven rain has been
identied (e.g. coastal high-rise buildings). For example,
in the Queensland Form 16, the addition of the AC and
IQF in item ‘4 Description of component/s certied’.
7. Auditing Checklist grade:
The AC grade highlights the importance of providing a
satisfactory installation to mitigate the potential for water
ingress. It is recommended to implement the AC and
the IQF for dierent activities during the construction
process and use the results as quality indicators of
the as built construction and in subsequent tendering.
Where tenderers have a poor record of providing quality
construction, they will receive poor experience ratings for
subsequent government tenders. This grade is provided
for each of the primary contractors and should be
reviewed on acceptance of the tendering process.
Other recommendations:
The following recommendations are to the wider industry
and not within the control domain of the Project’s industry
partners:
• Australian standards: The ‘openings’ standard for
Australia is AS 2047 – 2014. The water penetration
resistance test described in AS/NZS 4420.1:2016 occurs
under static wind load in which the test specimen is
subjected to water sprayed uniformly and continuously
over the exterior face. The Cyclone Testing Station (CTS)
at James Cook University is conducting tests to replicate
high dynamic range (HDR) pressure consistent with
cyclonic pressure. Their preliminary ndings indicate that
static pressure water penetration tests are inadequate for
characterising cyclonic events and most windows would
have some form of water penetration during cyclone
conditions. The CTS may propose new requirements for
AS 2047-2014 and AS/NZS 4420.1:2016.
• Knowledge transfer and education: Special emphasis
and additional eorts should be placed on educating
builders and installers on the importance of quality
installation of windows and glazed doors in order to
reduce the life-cycle maintenance costs of buildings.
The Australian Window Association (AWA) provides
industry training to improve familiarisation with relevant
windows and glazed doors installation. The Australian
Institute of Waterproong (AIW) provides industry
training to improve familiarisation with waterproong
systems. While there are courses and online materials
available, installers in regional northern Queensland may
not be receiving adequate training on the latest best
practice installation and waterproong procedures.
23
1. A maintenance schedule for building assets
should be provided as part of the design for
durability.
This could allow dierent strategies for maintenance
to be considered as part of service life planning (e.g.
replacement of parts and the frequency of inspection);
and it could facilitate maintenance actions by providing
safe and easy access to components that require
maintenance.
2. A maintenance manual for each building should
be made available for the people responsible for
its maintenance.
Public building assets are wide ranging and diverse.
Each building is exposed to dierent kinds and levels of
hazards that will require dierent kinds of maintenance
actions. This is particularly relevant to public assets
where personnel changes make it dicult to track how
decisions are made and systems are maintained over
the service life of the building.
3. Accurate as-built documentation should be made
available for maintenance purposes.
It is dicult to maintain buildings without reliable
as-built documentation. While design documentation
is generally available, as-built documentation is dicult
to compile because many changes are made during
construction that are dicult to keep track of.
4. Routine maintenance inspections should be used
to detect prevailing and new emerging risks to
building resilience.
For the building assets, routine maintenance inspection
reports used to initiate maintenance actions can also
be used to detect signs of emerging risks. This should
only be used as a preliminary scan to initiate further
investigation, as the causes of emerging risks are often
complex.
5. An appropriate procurement framework for
responsive maintenance should be developed.
Developing appropriate procurement arrangements
with suitable partnering/alliances and frameworks
for responsive maintenance should be considered to
enhance the eciency of outcomes and add value.
Responsive maintenance might be through employing
performance specications-based organisation of direct
labour and/or contractors. For example, a framework
of performance-based target cost alliances with
appropriate ‘pain and gain’ sharing is relevant for long
term maintenance of certain assets or earmarked key
components of building stock.
6. ‘Build back better’ for sustainable resilience
against natural hazards.
The ‘build back better’ for sustainable resilience
concept of the United Nations Oce for Disaster Risk
Reduction15 should be integrated into suitable repair,
renovation, retrot and reconstruction situations.
Any occurrence of major repair/ renovation/ retrot/
reconstruction of buildings or key components provides
valuable opportunities such as: (i) potential foolproof
prevention of subsequent mitigation requirements
for resilience of buildings against disaster risks;
and (ii) possibilities for enhancing the sustainability
futureproong.
Recommendations from
SBEnrc Project 1.53
24
7. Establish maintenance responsibilities for
whole-of-life value and sustainability.
Relevant mandatory and non-mandatory responsibilities
aimed at whole-of-life value and sustainability should
be established for the property owners, occupants and
stakeholders. For this, critical requirements include:
(i) improved understanding (e.g. through extensive
research) on lifecycle costs of all common building
types and key components; (ii) appropriate regulatory
and governance frameworks; (iii) checklists and
guidelines for non-mandatory responsibilities of dierent
parties; (iv) relevant arrangements for education and
training in this regard.
8. Develop smart infrastructure with advanced
digital integration for ecient maintenance and
eective resilience.
Developing smart infrastructure with advanced digital
integration should be considered to enhance the
eciency of maintenance activities and eectiveness
of resilience outcomes. The key opportunities identied
in this regard is integration of Building Information
Modelling (BIM), facility/asset management systems,
embedded real-time condition monitoring hardware and
software, smart analytics and intelligent systems with
block-chain cryptography.
25
A framework for specifying building maintenance
To implement these recommendations a ‘Framework
for specifying building maintenance’ could be created.
Specifying maintenance involves work at all levels from
design and construction to specic maintenance actions.
It could be designed to cover new buildings and/or existing
buildings involving one or all three types of maintenance
(essential safety measures, habitability and preventive).
An individual building manual for a specic building could
be compiled from information provided in the Framework.
For example, a non-mandatory framework for existing
buildings might contain the following components:
(i) A protocol for compiling a specic building
maintenance manual.
(ii) A protocol for regular building inspection and
reporting.
(iii) As-built record of elements that may require
maintenance or may be aected by maintenance
actions.
(iv) A maintenance schedule, including the required
maintenance level and frequency.
(v) If a performance-based design was used,
assumptions made in deriving the performance
solution relevant to the maintenance.
(vi) Lifecycle assessment and deterioration modelling
of key components of building assets.
(vii) Building product information relevant to maintenance
(and basic procurement/supply chain information).
(viii) Maintenance checklists (if relevant) for: (a) earthquake;
(b) bushre; (c) ood; (d) high winds and cyclones
(including water tightness of openings); and
(e) hailstorms.
26
”We receive detailed maintenance
advice and schedules for most
assets we purchase except our
most valuable built assets that are
also the most vulnerable
to extreme weather events. ”
27
Find out more:
Project webpage: https://sbenrc.com.au/research-programs/1-53/
Project YouTube video: https://youtu.be/0sZUuEraEBA
For further information:
Palaneeswaran Ekambaram
Swinburne University of Technology
Hawthorn, Victoria
pekambaram@swin.edu.au
+61 3 9214 8526
www.sbenrc.com.au
Rodney Stewart
Grith School of Engineering
Grith University - Gold Coast Campus
r.stewart@grith.edu.au
+61 7 5552 8778
This research would not have been possible
without the ongoing support of our core industry,
government and research partners: