OBSERVATORY 31 August 2026 Vaud Federal

Swiss new build overheating, Vaud turns to geocooling

A Minergie-certified railway complex handed over in Prilly in March 2026 hit 34 °C in a bedroom this summer. A week later, a Vaud MP asked for compulsory geocooling on every new ground-source heat pump in the canton.

By the Envergure editorial team

Swiss new build overheating has found its Vaud test case. A Minergie-certified complex handed over in Prilly in March 2026, built for 250 million francs, with bedrooms measured at 34 °C in the middle of the summer.

CANTON OF VAUD

Sun, symbol of summer heat A certified new building climbed to 34 °C

Swiss Federal Railways handed over the Central Malley residential complex in March 2026, 172 flats in Prilly built for 250 million francs. The building carries both the Minergie and SNBS labels.

During the heatwave, readings showed night-time temperatures of 28 to 29 °C inside the flats, and up to 34 °C in one bedroom on a separate measurement, while residents were using their blinds and ventilation normally (Watson).

34 °Cpeak measured in a bedroom
28 to 29 °Cnight-time temperatures recorded
172flats handed over in March 2026
250mfrancs, cost of the complex

Does an energy label protect a flat from a heatwave?

Not here. The Minergie and SNBS labels did not prevent Swiss new build overheating at Central Malley, and the two causes identified sit in the automated blind control, badly set, and in ventilation that falls short in high heat (Le Temps).

The lesson is blunt for a buyer and for a landlord alike. A flat can be new, certified and badly tuned. Summer comfort is checked with a thermometer in August, not on a label read in December.

CANTON OF VAUD

Document, symbol of a bill filed in parliament A motion would make geocooling compulsory in the canton

A week after those readings, Green MP Alberto Mocchi filed a motion in the Vaud cantonal parliament. It would require every new ground-source heat pump installed in the canton to include a geocooling system, and it would subsidise retrofitting the systems already in place.

The Prilly complex shows why the question belongs before the first spade goes in the ground. Geocooling already serves the offices and shops there, but not the flats.

Light bulb, symbol of a practical tip
Worth keeping. On a Vaud project with a ground-source heat pump, passive cooling has to be costed at design stage. The motion asks for a subsidy to adapt existing systems, which says enough about the price of fixing it afterwards.
CANTON OF VAUD

Banknotes, symbol of financial support 74 million francs for energy retrofits in 2026

The canton is putting 74 million francs into energy retrofit grants in 2026, 34 million from Vaud and 40 million from the Confederation. That is close to 22 % more than in 2025, and the canton expects it to trigger around 500 million francs of investment in construction, renewable energy and energy efficiency (vd.ch).

Retrofit grants and expected investment, canton of Vaud, 2026Energy retrofit grants, 202674 millionInvestment the canton expectsaround 500 million
The 2026 budget of the Vaud Programme Bâtiments, 34 million from the canton and 40 million from the Confederation, and the leverage announced on construction, renewable energy and energy efficiency. Source vd.ch.

What does the new AMU grant give an owner?

Hands-on support, on top of the money. The Assistance à la Maîtrise d’Usage grant follows owners and tenants through the whole of a renovation project, within the Vaud Programme Bâtiments. It is the new piece of the 2026 scheme.

For a Vaud owner hesitating between insulation and a new heating system, the programme now comes with someone to talk to and a bigger budget, two things it lacked last year.

FEDERAL

Globe, symbol of the federal level Lex Koller, a second consultation open since 26 August

The revision of the Lex Koller, the federal law on the acquisition of real estate by people abroad, has entered a second round. A second consultation phase opened on 26 August 2026, covering commercial buildings and shares in listed property companies and funds (admin.ch).

PhaseTimingWhat is put out for consultation
Preliminary draft15 April to 15 July 2026Authorisation for a main residence bought by nationals from outside the EU and EFTA, restrictions on holiday homes, on commercial buildings held purely as investments and on shares in listed property companies
Second phaseOpen since 26 August 2026Commercial buildings and shares in listed property companies and funds

The exact scope of this second phase and its deadline are not spelled out in the communication available so far. We will come back to it once the consultation text is published.

FEDERAL

Bars, symbol of the mortgage mix Saron gains ground, mostly in German-speaking Switzerland

Variable-rate Saron mortgages accounted for 24 % of the volume brokered by Moneypark in the first half of 2026, against 22 % at the end of 2025. The regional split says more than the trend (PME Magazine).

ScopeShare of Moneypark volume
Switzerland as a whole, end of 202522 %
Switzerland as a whole, first half of 202624 %
German-speaking Switzerland, first half of 202632 %
French-speaking Switzerland, first half of 202610 %

The Swiss National Bank policy rate is expected to stay where it is until the end of 2026, which leaves the choice between a fixed rate and Saron wide open. A French-speaking borrower who rules out the variable rate is following a regional habit rather than a market constraint.

Information circle, symbol of a warning
Careful with the shop-window rate. The cheapest five-year fixed rate advertised by Moneypark starts at 1.23 %. That figure comes from a broker rather than from an independent market average, so check it before promising it to a seller or a buyer.
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