Property Flood Resilience - Things to consider
The Property Flood Resilience Grant Scheme allows homeowners and businesses affected to access a grant of up to £5,000 to make their properties more resilient to the effects of future floods. While the Code of Practice (released in February 2020) provides the guidance and industry standards for delivering property flood resilience, those unfamiliar with the concept can read on for an introduction to the topic and some key points for consideration when looking to protect their property.
What is Property Flood Resilience?
Property Flood Resilience (PFR), sometimes referred to as Property Level Protection (PLP), is the term used to describe the ways in which a property can be protected from flood damage. The two main strategies used are keeping water out of a building, known as ‘resistance’, and improving the ability to recover a property following a flood, known as ‘resilience’.
Resistance. Things to consider…
A resistance strategy identifies routes of water entry through the fabric of a building and applies appropriate measures to prevent and ‘resist’ water entry. Flood doors, flood barriers, SMART airbricks and airbrick covers, as well as sealants and pumps are all commonly used measures. A resistance approach presents a relatively quick option and results in the least disruption to the home and living space.
Identifying how water will enter a building requires background knowledge, experience and a specific understanding of how building design and construction materials react to flood water. Keeping water out of a building typically requires multiple measures, often using manual products (put in place when a flood is expected) on grounds of affordability, and automatic products (self-activating) on grounds of practicality. In addition to mitigating against the presence of groundwater, pump systems help to prevent or slow the rising of water within a property should a defence product fail, or water enter via an unidentified route.
The kitemark for flood protection products is PAS1188, meaning these products have been independently tested under specific flood conditions set by the British Standards Institute (BSI). Product maintenance is equally as important in preventing unit failures and ensuring a defence product will work as intended when it is needed most. Over time, rubber seals will perish, and extremes of hot and cold weather can lead to the expansion, contraction, hardening and cracking of plastics, sealants and other materials exposed to the elements. Products such as flood doors and windows are often accompanied by guarantees which remain dependent on product servicing at specified intervals; usually by either the manufacturer or supplier for an additional cost or service charge.
Keeping water out of a building also presents other factors to be considered, including the pressure that flood water exerts on external walls. The pressure of water increases with its depth and oncoming rate of flow, meaning consideration must be given to the height to which a property can be safely protected without risking structural damage. While government guidelines suggest 600mm (2ft) as a safe height to resist water entry, many buildings in flood risk areas are protected to around 900mm (3ft). Beyond the safe standard of protection, it is advised that flood water be allowed to overtop barriers and enter a property in order to prevent catastrophic damage. The force constantly applied to external walls by flood water means that even a relatively light impact from floating objects and debris, such as vehicles and tree limbs, can be enough to cause a wall to buckle and collapse; posing further risk to life.
Resilience. Things to consider…
A resilience strategy improves the recoverability of a flooded property by reducing the impact on the building and its residents. If done effectively, flood resilience measures would result in damage reduction and the quick recovery and reoccupation of a property, potentially eliminating the need for an insurance claim.
Water resilient wall boards and skim, hardwoods, plastic skirting and ceramic wood-effect floor tiles are all materials which can be cleaned, disinfected and remain in place following a flood. Sump and pump systems, stainless steel kitchen units and raising the height of plug sockets, utility meters and appliances all represent good, flood resilient practices which can be implemented during restoration.
A comprehensive approach to resilience can be significantly more expensive and disruptive, and those undertaking such an approach often do so directly after their home has flooded; when the re-instatement phase presents an incredibly advantageous opportunity to build-in water resilient materials and design principles. With the insurance industry traditionally reluctant to engage with flood resilient repair, homeowners wanting to adopt resilience are often faced with reaching an agreeable settlement figure with their insurer. While investment in a water resilient building can pay dividends over the longer-term, residents choosing to project manage the installation themselves may find that it could extend the amount of time they are away from their home; potentially adding additional stress and strain on family and finances.
With less than one-in-three owners researching a property’s flood risk before buying, and close to two-thirds of owners having never checked their flood risk, the Association of British Insurers (ABI) has made proposals which would see homeowners in flood risk areas require a property flood resilience survey as part of the selling process. These proposals would see the mainstream adoption of a Property Flood Resilience Database (PFR-d); a traffic light system and scoring model similar to that of the Energy Performance Certification Scheme. The required PFR survey and accompanying report would inform potential buyers of a property’s flood risk, its current level of resistance and resilience to flooding, and the subsequent works required to improve it.
Implications on Insurance
While Flood Re currently presents a means for many homeowners to obtain affordable flood insurance cover, the scheme will only remain in place until 2039, at which point pricing will no longer be capped and domestic flood risk policies will revert to a free market. With PFR scores collated on an insurance industry accessible database, it would provide a fair and objective means by which a property’s level of resistance and/or resilience to flooding could be directly reflected in the price of insurance premiums; the higher the PFR score, the lower the cost of flood insurance cover.
So why is this important in the context of a resilience strategy?
Water resilient design, construction and materials present an appealing proposition to insurers. Unlike a resistance approach on which success is reliant on human and technological interventions, a resilience approach effectively removes these variables, eliminating the risk of human error and product failure. Based on the principle that if it can’t be damaged it won’t need repair, only water resilient materials and design offers the greatest chance of damage reduction if flood water enters a property. Should such a scheme be introduced at a future date, it would be for this reason that resilience measures would score higher than resistance measures as part of any PFR scoring process.
Which way to go – Resistance, Resilience or both?
While keeping spend relative and proportionate to the level of flood risk faced by a property could be considered a sensible approach, each circumstance is unique, and a holistic view best serves to cover all bases. In addition to the thoughts discussed above, the most appropriate strategy to take when protecting a property can only be derived from the consideration and assessment of a range of different factors. Some key ones are mentioned below…
The Property’s Flood Risk
- Identify ALL sources of flood risk; river and coastal, surface water and sewer, reservoir and groundwater, as well as the risk posed by canals and any other ‘ordinary’ watercourse and natural drainage system, such as brooks, streams and dykes.
- Consider the expected frequency of flood events from different sources.
- Consider the possible depth and duration of flood water from different sources and return periods.
To find out more about flood risk, read our ‘Understanding Flood Risk’ blog here: https://bit.ly/2T17a8F
The Property and its location
- Consider the type, age, construction, condition, operation and contents of the property. Semi-detached or terraced properties can also flood as a result of an attached neighbouring property yielding to water ingress, either via the sub floor area or via party walls where the permeability of masonry types and wall finishes will affect seepage rates.
- If the property is a listed building or located within a heritage / conservation area there may be restrictions as to the measures and products which can be used to protect the building. Clarification on permitted products and works can be obtained through consultation with the local planning department or building control.
- Is a reliable flood warning trigger available and would it provide enough lead-time for the resident to respond?
The Resident(s) and their circumstances
- The availability of the resident and how quickly they can return to their property to act is as important as the defences themselves. If the homeowner is regularly away from the property or is unable to leave work, automatic flood protection products or resilience measures would offer the most suitable way forward.
- The age, health and mobility of the resident will impact significantly on their ability to manually install flood defences, as well as their capability to clean and recover their home following a flood.
- The budget to undertake such works will ultimately determine what can and cannot be achieved. Where communities are significantly affected by large-scale flooding, the UK government may provide property flood resilience grant schemes through local authorities, allowing eligible homeowners to claim up to £5,000 worth of funding to reduce the impact of future floods.
Those unsure how to proceed in protecting their home would be well advised to have a property flood resilience survey carried out by an experienced professional. While there will be a charge for such a survey and report, it should adopt a rigorous and meticulous approach to flood risk assessment and mitigation, as well as consider some of the wider and more personal attributes mentioned above; allowing residents to understand their risk and the resilience strategies recommended.
For more information of on property flood resilience, you can download the Property Flood Resilience Toolkit on the following link: https://bit.ly/2Tz8pf6
For further information on flood resilience, visit the Flood Hub on the following link: www.thefloodhub.co.uk