Right now, we are in the middle of the hottest heatwave Europe has known. People are struggling in record-breaking temperatures. And the records keep breaking — sometimes year on year, or, like now, several times in a single week.
I am an advocate for cooler cities with over 20 years of practical experience. The spaces I design are essential to a well-functioning city. The spaces that mechanical air conditioning cannot solve. The spaces that make or break the quality of urban life. With the climate heating so quickly, it is easy to understand why yesterday’s designers did not plan for the heat we now face.
Expect new thinking in the years ahead.
The Gulf is a different story. The capital cities — Abu Dhabi, Muscat, Riyadh and others — are no strangers to extreme heat. Their historic districts, where they survive, were designed in response to climate, but today they are only small pockets. The modern districts, born in the post-oil era of air conditioning, are far less adapted to the local climate.
There are, though, cities around the Gulf that show what good design can do. I have walked the streets of Isfahan, designed for extreme heat. And having walked other great streets around the world — Barcelona, Melbourne, New York — I know from experience that design makes a difference, a decisive one. The difference between feeling comfortable or not. Between wanting to go outside or not. Between dangerously unhealthy or not. I do not need convincing that design makes a difference.
know the difference between feeling comfortable or not, wanting to go outside or not, being dangerously unhealthy or not
I work with a team committed to creating cooler cities. It is a cross-disciplinary effort, and so is our team: urban designers, landscape architects, horticulturalists and micro-climate researchers. One thing we have learned is that there are huge gaps between the science, the theory and the practice. Even though we can measure and simulate, do we produce meaningful results that translate into the best design outcomes?
I’m going to write about how to make shadow studies that won’t be shelved as irrelevant data, but used to inform design and improve the thermal performance of outdoor spaces.
This post is part of an ongoing series on thermal comfort and placemaking. A research project with our Green Different Network partner, Dr. Nihal Al Sabbagh – Founder of Environas.
Consultants produce shadow studies for the summer solstice, the winter solstice, and the equinox. Have you ever asked why those dates?
Take the winter solstice. Is knowing where shadows fall on that day useful for understanding thermal comfort? No. It sits in the middle of the cool season, when sitting and walking outside are comfortable in sun or shade alike — there is no comfort problem to study. And if the aim were the coldest day, the solstice isn’t it; the cold arrives weeks later, in January. The solstice is the shortest day, not the coldest one.
The summer solstice is marginally more meaningful. At over 43°C, shade removes heat from direct sunlight but air temperature and humidity remain beyond comfortable. Why study shadows on a day nobody is sitting outside? Furthermore, it isn’t even the hottest day; peak heat lands around 31 July. The equinoxes are calendar halfway points, not comfort events. Not one of these four dates was chosen because it is when a space tips between usable and unusable.
That tipping point — the shoulder period — is when shade makes a difference in behaviour. Shadow studies on these dates meaningfully inform and influence design outcomes. We haven’t seen a shadow-study brief that asks for this — so we wrote one ourselves.
To establish where and when shade is needed to make outdoor spaces usable, and to evidence how the landscape design extends the usable outdoor season. The study must demonstrate how shadow studies have informed design decisions.
Study the shoulder periods — the weeks either side of summer when a space crosses between comfortable and uncomfortable — not the solstices or equinoxes. Dates differ by activity, because a walking person generates more heat than someone sitting.
Solar noon alone misses how people use space. Study the hours that match the programme. For example, for dining and active public realm, 0800, 1300, and 1800 (morning, lunch, early evening). Shadows move through the day, so each hour matters in its own right: a breakfast café needs shade in the morning, a lunch terrace needs it overhead at midday, an evening venue needs it late. Midday is the most demanding for comfort, but it is not a substitute for the others — match the shade to where and when each space is actually used.
The table below maps activities and study dates, and explains the purpose of these combinations.
Use type | Study date(s) | Why this date |
|---|---|---|
Sitting — discretionary (dining, seating) | Pre-summer: ~early March Post-summer: ~mid-November | The boundaries of the sit-comfortable season — where shade decides whether a space is used and pushes each boundary outward. How far depends on the site; quantify it. |
Play — discretionary (playgrounds, active areas) | Comfortable window: ~late December to late January only | These must be shaded regardless — for UV protection, not comfort. Children’s skin is vulnerable and UV stays high through the cool, busy months, so shade playgrounds regardless of the thermal calendar. |
Walking — discretionary routes (promenades, retail streets) | Pre-summer: ~mid-February
Post-summer: ~early December | Walking’s comfortable window is narrower than sitting’s. People stroll these by choice, so comfort still governs use. |
Walking — mandatory routes (paths, entrances, assembly) | Hottest day: ~31 July (not the solstice) | These must be shaded regardless — it’s a health and safety matter, not a comfort choice. The worst-case study isn’t deciding whether to shade; it demonstrates that amandatory provision is met. |
Compliance (if a rating scheme demands it) | Solstices / equinox | Keep only to satisfy the scheme — a separate deliverable, not design-driving analysis. |
A shadow study shows where shade falls and when. It does not simulate comfort, which also depends on wind, humidity, and radiated heat from surrounding surfaces. Treat it as a strong indication, not the full picture.
Where greater accuracy is needed, commission thermal comfort simulation (ENVI-met, Ladybug, or similar) as a design tool, not a tick-box. It can test whether a particular canopy, planting, or building orientation extends the season further than shade alone, and it catches false assumptions — spaces that look shaded at the right hour but stay hot from radiant heat off nearby surfaces. A shadow study alone will not show that.
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