Architecture · Climate
Building With the Wind
Wind decides where you sit, where you eat and where the pool is usable. Almost nobody surveys it, and every unused terrace is the result.
Sunlight gets modelled. Views get photographed. Wind gets ignored, and then the owners spend a decade eating indoors on beautiful evenings, unable to explain why the terrace never quite works.
The first hour of research is free
Every regional meteorological service publishes wind roses: the direction and frequency of wind by month. Fifteen minutes with the one for your area tells you which side of the house the prevailing wind arrives from, and whether it changes between winter and summer, which along most coasts it does.
Then walk the site. Local topography rewrites regional data completely. A ridge, a stand of pines, a neighbour's garage: each of them creates a lee that extends roughly seven to ten times its height downwind. That lee is where your outdoor dining table belongs.
Three tools, in order of usefulness
The return wall. A solid wall at one end of a terrace, roughly 1.8 metres high and 2 to 3 metres long, perpendicular to the prevailing direction. It costs the price of a sofa and adds six weeks to each end of the outdoor season.
The planted screen. Permeable planting slows wind better than a solid fence, which creates turbulence and a nasty rolling eddy on its downwind side. Aim for something like fifty per cent porosity: cypress, tamarisk, oleander, a slatted timber screen with gaps.
The level change. Dropping a seating area 60 centimetres below the terrace deck puts a seated person's head below the airflow. Sunken lounges look like a style decision. They are a wind decision that happens to look good.
The most-used square metre of any coastal house is the corner where the wind stops. Find it before you place the kitchen.
Elena Batista, landscape architect
Wind and the front door
There is a practical detail that separates houses that feel calm from houses that slam. If the entrance faces the prevailing wind and the plan is open, every opening of the front door pressurises the whole house: doors bang, papers move, the fire smokes.
The old solutions still work. A porch. A lobby with two doors. A screen wall placed a metre in front of the entrance, angled to break the flow. None of them are expensive, and all of them have to be in the plan from the beginning.
The pool that nobody swims in
A pool placed for the view rather than the shelter will be cold, choppy and used twice a summer. Water loses heat to wind far faster than to air temperature, and a breeze of 15 km/h across an open pool can cost several degrees.
Put the pool in the lee. Put the view on the walk between the house and the pool. Nobody looks at the horizon while swimming lengths anyway.
Wind and the building itself
Wind does not only decide where people sit. It decides how much heat a house loses. An exposed building on a ridge can lose thirty to fifty per cent more energy through infiltration than the same building in a sheltered position, because pressure differences drive air through every gap in the envelope.
The response is not thicker insulation. It is airtightness: a continuous membrane or a wet-plastered internal layer, with every service penetration sealed, tested by a blower door before the finishes go on. On an exposed site this is the single highest-return item in the specification, and it costs almost nothing if it is planned rather than patched.
Noise, the underrated factor
There is a threshold, somewhere around 25 kilometres an hour, above which people stop using outdoor spaces regardless of temperature. It is not discomfort, it is the sound: wind noise in the ears, in planting, in loose fittings, and the constant low roar that makes conversation an effort.
Solid barriers stop wind and reflect noise. Permeable planting slows both, which is why a garden with a hedge on the windward side feels calmer than one with a wall, even when the measured wind speed is identical. And loose elements, unlined pergola fabric, hollow metal furniture, badly fixed shutters, generate their own noise at speeds far below the threshold. Check for those first. They are free to fix and they ruin more terraces than the wind itself.
The summary a builder will accept
Sun defines where the house looks. Wind defines where the house is used. Design the elevation for one, and the outdoor rooms for the other, and the building will be occupied nine months a year instead of three.
