According to Scotland's solar energy trade body, the Scottish Government’s proposed energy efficiency standard for buildings would be obsolete before it comes into force.

What is more, proceeding as intended could leave solar power absent from new rooftops. This is even after the EU mandated solar technology for new-build properties—and England is expected to follow suit.

The Scottish Government opened a consultation this week on implementing rules inspired by the international Passivhaus standard.

In summary, Passivhaus buildings have very high levels of insulation and airtightness, leading to exceedingly low energy demand.

They also set an overall energy performance target covering space heating, cooking, and appliances.

The paper states, “There is increasing recognition and application of the standard, which contributes positively to overall energy and net zero objectives.”

A plan to implement it was announced in early 2023, based on measures set out in Alex Rowley MSP’s proposed Domestic Building Environmental Standards (Scotland) Bill.

The consultation is based on the original, or ‘classic’ Passivhaus standard, which was devised decades ago when renewables were rare and expensive

With solar power and smart energy systems now cheap and common, time-of-use tariffs available, and road transport becoming increasingly electrified, it is no longer appropriate to look to a standard from a profoundly different time.

Passivhaus Classic has long been superseded by the more ambitious ‘Plus’ and ‘Premium’ forms, which mandate the installation of renewable energy—which could also include solar thermal systems for producing hot water.

However, solar power is not mentioned at all in the consultation, which covers both domestic and non-domestic properties, and it does not go as far on energy efficiency as the Passivhaus Classic.