There are a number of strategies and solutions available to adapt our built environment and infrastructure to the impacts of climate change.
Many adaptation strategies can contribute to wider policy objectives and the creation of an attractive, high quality public realm. Also, many climate change adaptation solutions are complementary and may need to be incorporated alongside each other to achieve an effective overall solution to the risk. For example, the orientation of the building can be considered alongside solar shading solutions and choice of building and landscaping materials.
Some adaptation solutions may also provide opportunities for meeting other sustianability objectives, such as tree planting and sustainable drainage or solar shading and reducing carbon dioxide emissions.
Careful consideration is needed when designing adaptation solutions. It is important not to preclude future adaptation (e.g. by incorporating flexibility in the design) and to ensure that adaptation measures, wherever possible, do not contribute to an increase in carbon emissions.
The use of spatial scales
Spatial scales can be used to categorise development based on key design characteristics: size, function and location. The appropriateness of different adaptation strategies and solutions will vary according to these characteristics. Each of the solutions presented and discussed in this module will indicate which scale(s) it is most applicable to:
The adaptation solutions are categorised according to the key risk area and the appropriate spatial scale(s) at which each solution could be applied.
At the building scale it will be important to balance requirements through careful design, particularly where energy efficiency measures have the potential to exacerbate summer heat risks.
For example, while mechanical air conditioning is an obvious way to guarantee thermal comfort during hotter summers, this solution would contribute additional heat to the surrounding air, significantly increasing energy demands from the cooling equipment leading to increased carbon dioxide emissions.
Opportunities exist through using passive solutions first and then finding the best mechanical solution to meet any remaining cooling requirement.
At the neighbourhood scale, efforts to manage high temperatures should focus on providing cool and shaded outdoor areas. If well designed, adaptation at this scale can also benefit internal spaces, e.g. street trees provide cooling outdoors, as well as shading buildings.
Town or urban extension scale
At the town or urban extension scale, opportunities for reducing the Urban Heat Island effect, via large scale infrastructure and landscape design, should be explored.
Masterplans should allow for the integration of water (such as ponds and lakes), open space and built form through green infrastructure and bluespace strategies. This should take into account the range of cross benefits that adaptation options offer, as well as the potential for adaptation solutions to conflict with one another.
Precipitation and flooding
At the building scale, the aim should be to implement measures that reducing the building’s contribution to flood risk, reduce the building’s vulnerability to flooding and increase the building’s resilience during flood events. However, in some circumstances it may be more appropriate to relocate vulnerable land uses out of flood risk areas.
Consideration should also be made for where adaptation solutions may conflict with other adaptation measures, or with efforts toward climate change mitigation. This could include circumstances where the use of solar photovoltaic panels may compete for roof space with green roofs.
At the neighbourhood scale, efforts to manage flood risk should focus on understanding where this risk is highest and protecting those properties. The use of sustainable drainage systems should play a major role in any drainage strategy.
In well designed schemes, where adaptation solutions have been integrated at an early stage, these solutions can bring additional benefits in terms of cooling, water quality, promotion of biodiversity, resource management, or enhancement of public spaces. These are highlighted in the solutions below.
Town or urban extension scale
At the town or urban extension scale developments are located near rivers, fluvial flooding will pose the biggest flood threat. The greatest opportunities for reducing this threat lie with adopting large scale infrastructure, such as flood defence systems and drainage networks, and integrating spatial plans, i.e. green space and the built environment) with flood management plans.
If large scale development is planned for undeveloped land, such as greenfield land, the risk of flooding from surface water runoff, due to new and extensive areas of hard surfacing, will pose a significant threat. It is crucial that consideration for how the development will cope with surface water flooding is given at the initial concept of design stage of the development. Similarly with the neighbourhood scale, adaptation solutions that have been integrated at an early stage may provide additional benefits.
Pressure on water resources
As the rainfall regime in Hertfordshire changes due to climate change, and additional built development takes place, the management and storage of water for extraction, consumption, treatment and general use will become increasingly more challenging. It is therefore vital that demand on primary water resources is reduced or managed as far as practicable and methods are applied to ensure continuing water quality and quantity.
Adaptation solutions may also provide multiple opportunities for reducing water use and improving water quality, if carefully applied.
At the building scale, the multiple benefits offered by some solutions should be exploited. These benefits are highlighted in the solutions described below. For instance, rainwater harvesting and storage can collect runoff from the roof helping to minimise surface water runoff and reduce flooding, whilst providing a non-mains supply source of water for use by the building.
At the neighbourhood scale, opportunities for enhancing the built environment through the creation of ‘bluespace’, such as lakes or ponds, should be explored. Community scale water re-use systems, such as rainwater harvesting present good opportunities for managing water use.
Town or urban extension scale
At the town or urban extension scale, efforts should be focused on managing , protecting and enhancing watercourses, such as rivers and lakes, to allow them to continue providing an important water resource and important habitats for wildlife and recreational opportunities.
It is equally important to safeguard groundwater sources, particularly those just below ground level, as these may contribute to sustaining a secure and stable water supply. Consideration should be given to the current and future capacity of water resources.
Many of the solutions available for minimising or eliminating the risk of ground instability, or for adapting the built environment to cope with this risk, offer additional benefits in terms of reducing flood risk, overheating and protecting water resource. Therefore, many of these solutions could be viewed as cost-effective due to their dual or multiple functions.
At the building scale, efforts should be focussed on reinforcement and appropriate design and construction, taking care not to conflict the need for structural stability with the need for high quality adaptive design, and vice versa.
For example, materials such as timber frame are more flexible than concrete or brick frames and therefore less susceptible to subsidence. However, there is less potential for thermal mass and thus more potential for overheating. In addition, timber is less flood resilient than concrete.
At the neighbourhood scale, adaptation should be incorporated by providing deeper, stronger and well-drained foundations. Opportunities for adapting existing development include vegetation management and the maintenance/upgrade of drainage networks.
In new developments, synergies with flood risk and water resource management should be explored, particularly in terms of sustainable drainage.
Town/urban extension scale
At the town/urban extension scale, action should focus on ground stability engineering, particularly addressing any areas that may present landslide potential. Solutions lie in the use of large scale infrastructure and vegetation management and, if well designed, opportunities exist for providing enhanced quality of public spaces. Synergies with flood risk and water resource management should be explored.