Climate Adaptation and Resilience: Heat Islands, Water Management and Urban Design
In the fight against climate change, cutting emissions — "mitigation" — has long been at the centre of the agenda. Yet heat waves, sudden and intense rainfall, and drought have already become part of everyday life. For this reason a second heading has been added alongside mitigation: adaptation. The ability of cities, buildings and infrastructure to keep functioning under changing conditions is now a design criterion.
Adaptation does not try to solve the problem within the boundaries of a single building. A building's cooling performance depends on the temperature of the surfaces around it; whether its basement floods depends on how the neighbourhood manages its rainwater. That is why climate adaptation is, by its very nature, a subject that must be considered at the scale of the city.
The Urban Heat Island: The Heat Cities Produce Themselves
The urban heat island is the condition in which densely built-up areas are warmer than the surrounding rural regions. Asphalt, concrete, stone and roof surfaces absorb solar radiation throughout the day and heat up, then release that heat slowly at night. As a result, the temperature difference persists not only during the day but through the night as well.
In Türkiye, the city where this effect is discussed most is Istanbul. Observation and modelling studies show that the intensity of the heat island in Istanbul is around 3 degrees Celsius; model simulations indicate that this difference could rise to as much as 6 degrees as the atmospheric circulation between the countryside and the city changes.
What is truly striking is that the form of development changes the outcome. In the same study, a horizontal-growth scenario based on building over vacant land shows that the temperature increases are not confined to the built-up areas but spread to their surroundings as well, reaching up to 3 degrees. By contrast, in a vertical-growth scenario in which the number of storeys of low- and mid-rise buildings is doubled, the increase stays at around 1 degree.
This finding shows that climate adaptation is not only about the choice of materials or technology. How much of the land is built on, and how much is left permeable and green, is at least as decisive as the detail of a façade.
The Tools for Reducing Heat
The methods used to ease the heat island effect at the city scale are largely shared:
- Shade and tree cover: Trees provide shade and cool their surroundings through transpiration. Shading walking routes directly affects how usable public space is in the summer months.
- Highly reflective surfaces: Light-coloured, reflective roof and paving materials reduce the heat a surface stores.
- Green roofs and façades: Vegetated surfaces both lower heat gain and retain part of the rainwater.
- Permeable ground: Water-absorbing pavements both cool the surface and reduce run-off.
- Water elements and blue infrastructure: Pools, ponds and stream beds balance the microclimate.
The common feature of these solutions is that their effect remains limited when applied on their own. The real difference emerges when they are applied consistently across a whole district rather than a single plot.
Water Management: Treating Rain as a Resource, Not Waste
The second heading of climate adaptation is water. Traditional urban planning treats rainwater as waste to be removed from the city as fast as possible. The "sponge city" approach, by contrast, aims to turn water into a value that is managed on site, stored and used as a resource.
The model rests on designing infrastructure and surface coverings so that they can absorb, retain, filter and reuse rainwater. Since 2015 China has made this state policy and plans to build, in more than 30 cities by 2030, infrastructure capable of absorbing 70 percent of rainwater. In Germany, Berlin and Hamburg stand out with green roofs, permeable pavements and the restoration of natural watercourses; in the Netherlands, Rotterdam and Amsterdam do so with integrated solutions that combine permeable surfaces with canals.
There are examples in Türkiye as well. Under the Sponge City İzmir project, rainwater storage tanks, rain gardens, permeable surfaces and infiltration systems are being put in place; what distinguishes the project is that it uses nature-based solutions together with the existing infrastructure rather than replacing it entirely. Impermeable roads and car parks covered with asphalt and concrete are being turned into permeable areas, and the collected water is directed to parks and median strips. In Ödemiş, a biological infiltration pond that will store 60,000 cubic metres of water underground has been built.
The implication of these applications for the construction and real-estate sector is clear: car parks, squares and landscaped areas are not merely aesthetic elements but also a water infrastructure. How much of a plot's rainwater is retained directly affects flood risk and the load on the network.
Bringing Adaptation into the Early Stages of Design
Climate adaptation is not a list of equipment added at the end of a project; it is an approach shaped by the first decisions. The settlement plan, the orientation of the massing, the ratio of permeable area, the preservation of the tree cover and the reading of the topography are decisions that are hard to make up for later.
For this reason, adaptation should be addressed in three stages. The first is risk analysis: assessing the current and future condition of the site in terms of temperature, flooding and water resources. The second is design decisions: setting density, permeable surfaces and green cover according to that analysis. The third is operation: measuring how the system actually performs and improving it over time.
Adaptation is also a financial matter. Assets that carry climate risk are increasingly under close scrutiny in terms of insurability, financing cost and long-term value. Resilience, though it may look like a cost item today, is becoming one of the factors that determine an asset's performance over its entire lifetime.
Our Approach as Koray Group
As Koray Group, we see climate adaptation as a fundamental criterion to be addressed at the design stage of our projects. Operating in construction, real estate and energy under one roof allows us to evaluate a building's energy performance, its surrounding landscape and its relationship with water not separately but holistically. In our projects we take care to preserve the permeable and green texture of open spaces, to protect the existing trees, and to align settlement decisions with the natural structure of the land.
What our more than 70 years of experience has taught us is that long-lived buildings must be prepared not only for today's conditions but for tomorrow's as well. Climate adaptation is therefore not an add-on for us; it is a natural part of our approach to producing sustainable projects and shaping them through innovation.