June 2026 will stay in the memory of everyone living in Ticino. From 17 June a heatwave swept across the whole of Switzerland, with the Confederation declaring danger level 3 out of 4. In low-lying areas north and south of the Alps there were twelve consecutive tropical days, and according to MeteoSwiss a ten-day heatwave this early in the summer is almost unprecedented. In Lugano the average daily maximum reached 32.7 °C.

It is not an isolated case: spring 2026 was the third warmest ever measured in Switzerland, and temperatures had already hit 30 degrees at the end of May. Summer comfort at home has become a design issue, no longer something to fix by buying an air conditioner.

Heat comes in mainly through the glass

Contemporary homes have large glazed surfaces, and that is a good thing: light, views, wellbeing. But in summer the sun passing through the glass turns into heat that stays trapped inside. That is why the first rule of passive cooling is simple: stop the sun before it gets in.

An internal blind helps little, because the heat is already inside. The most effective solutions are:

• external shading such as brise-soleil, awnings and shutters;
• shading integrated into the glass unit, working between the two panes.

The ScreenLine® blinds by Pellini – Finglas belong to the second group: venetian, pleated or roller blinds sealed inside the insulating glass, protected from dust and weather, with no maintenance. By tilting the slats you decide how much light to let in and how much heat to keep out. BeSpace is their official distributor for Switzerland.

Windows and glass: the choice is made at the design stage

A high-performance window is not only useful in winter. Well-insulated, properly installed frames stop outside heat from seeping in at the edges, and integrated shading systems make daily use easier. This is the solution adopted by Bomè in mountain projects with timber-aluminium windows, triple glazing and integrated shades.

The glass must also be chosen carefully: its solar factor shows how much of the sun’s energy passes inside. With TaccaGlass we assess the most suitable insulating glass for each façade’s orientation: a south-facing front on the lake does not have the same needs as a north-facing one.

An envelope that acts as a shield

Walls and roof should not only insulate: they should slow the passage of heat, so that the afternoon peak reaches the interior reduced and delayed, when in the evening the windows can already be opened. Buildings with a load-bearing timber structure by Abito Holz provide high thermal insulation and good thermo-hygrometric comfort, in summer as in winter.

Greenery as a natural air conditioner

A green roof or wall heats up far less than a concrete or dark stone surface. Plants provide shade, hold moisture and release it slowly: the microclimate around the house changes, especially in towns, where asphalt and concrete store heat for hours. The vertical gardens by Verde Profilo, indoors and outdoors, bring this effect even where there is no space at ground level.

Manage, don’t just build

The best shading is of little use if it stays open at the wrong times. Control systems by Lutron automate blinds and lights according to the time of day and orientation: shading closes when the sun hits the façade and opens again when it is time to ventilate.

Checklist for a cool home in summer

1. Shade the glass from the outside or inside the glass unit, not from the inside.
2. Choose the glass according to the orientation of each façade.
3. Plan for night-time cross ventilation from the design stage.
4. Use light-coloured surfaces and greenery on exposed roofs, terraces and walls.
5. Automate shading and lighting.
6. Keep air conditioning as back-up, not as the only defence.

With Architectural Things we design homes for a changing climate, bringing together architecture and technical partners. If your home became unbearable during the last heatwave, contact us: we start with a site visit.

Read more: Outdoor design and sustainability: toward responsible living.

Sources: MeteoSwiss heatwave review – Ticinonline · Record temperatures – laRegione · Heatwave on the way – blue News