Climate change will have a major impact on the performance of the UK’s social housing sector, which comprises 2.5 million housing units across 1500 social housing providers. Octavia Housing is responsible for 4000 of these homes, centred in West London and provides the organisational setting for this work.
This project used an adaptation framework model to translate climate risks into meaningful impact scenarios for asset managers. It integrated these into a performancebased built asset management model to establish a series of performance thresholds and triggers to prioritise future adaptation interventions. A range of generic adaptation solutions to flooding and overheating have been collated and reviewed against typical housing unit archetypes. An outline adaptation plan has been developed that prioritises adaptations that address current climate threats and provides for the routine re-evaluation of future threats. Such an approach should ensure that Octavia’s homes continue to support their tenants well-being.
Further project details
1. What approach did you take in assessing risks and identifying adaptation measures to mitigate the risks?
Risk assessment: publically available documentation based on UKCP09 projections was consulted, georeferenced and analysed alongside georeferenced stock condition data to distinguish properties vulnerable to flood, heat wave and subsidence risks.
Adaptation measures: generic adaptation measures for flooding and overheating were identified from publically available documentation and their applicability to Octavia’s stock was assessed against typical housing unit archetypes.
2. How have you communicated the risks and recommendations with your client? What methods worked well?
Climate risks were communicated through a series of impact scenarios which were used to identify the vulnerability and coping capacity of housing unit archetypes to flooding and overheating.
The impact of the climate risks on performance of those archetypes that were highly vulnerable and had a low coping capacity were communicated through sample building survey reports.
The implications of the climate risks were extrapolated across Octavia’s housing portfolio and the consequences were communicated through a series of impact grids.
The recommendations for adaptation and further investigation were communicated through an outline adaptation strategy.
All the above worked well although the extrapolation from typical archetypes to portfolio level impacts left many unanswered questions.
3. What tools have you used to assess overheating and flood risks?
The climate impact scenarios for flooding and overheating were derived from publically available toolkits that had used the UKCP09 projections to evaluate the adaptation risks of London’s housing (e.g. the EPSRC CREW project, The London Adaptation Strategy, local authority flood risk assessments etc). Octavia Housing’s stock condition database was used in conjunction with GoogleEarth, GoogleStreetview and ArcMap to identify those properties that were at risk of flooding. Building level surveys of typical archetype housing units were used to assess the effectiveness of a range of adaptations to reduce vulnerability and improve resilience of Octavia’s housing units.
The impact of overheating was assessed using London wide predictions for future temperature profiles and HNS for England heat wave thresholds. The CREW Project Retrofit Adaptation toolkit was used to assess the potential for a range of adaptations to reduce overheating in the archetype housing units.
Octavia address subsidence through their responsive maintenance programme and water consumption through their mitigation programme.
4. What has the client agreed to implement as a result of your adaptation work?
The client has instigated detailed evaluation of the cost effectiveness of flood resilience measures for its highly vulnerable basement flats and introduced a tenant briefing regime for those tenants in such properties.
The client has agreed to enhance its stock condition survey process to collect additional data that will allow it to regularly monitor the vulnerability and resilience of individual housing units rather than relying on typical archetypes.
5. What were the major challenges so far in doing this adaptation work?
The main climate risk to Octavia is pluvial flooding. However, pluvial flood risk maps are not yet widely available. As such much of the risk assessment had to be based on assumptions of flood risk. This reduces the currency of projections and leads to a responsive approach to adaptation planning where only immediate risks are prioritised. This runs counter to the goals of long term adaptation of the built environment.
6. What advice would you give others undertaking adaptation strategies?
Make use of publically available information to assess current climate risks that your properties face and then extrapolate the potential impacts that climate change may have. In this way you can develop an adaptation strategy that deals with current problems whilst you gather the information, both in house, and from UK wide sources, to allow longer term adaptations to be programmed into a built asset management plan.
Adaptation work can be expensive. To minimise this built asset management plans should look to undertake works as part of planned works or reinvestment/ improvement programmes. For example, we have found that there is synergy between proposed energy efficiency and climate change ad