New energy-efficiency rules could make more than a quarter of Aberdeen's office space obsolete overnight.
Analysis from Knight Frank also suggests that a swathe of Granite City office stock may be unlettable by 2030 without improvements.
The Press & Journal says a consultation document recently released by the Scottish Government set out its intention to align with the EPC (energy performance certificate) system used elsewhere in the UK.
The changes proposed would see the validity of Scottish EPCs reduced from 10 years to five.
The MEES rules will also be tightened twice more in the coming years.
According to Knight Frank, 28% of Aberdeen's office space has an EPC rating of E or below.
It could all become unusable if Holyrood follows the minimum energy-efficiency standards (MEES) that apply in England and Wales.
Rules tightened
The MEES rules will also be tightened twice more in the coming years.
From April 2027, commercial properties will need at least an EPC rating of C to be lettable.
Three years later, the bar will be raised again to include only buildings with an A or a B EPC rating.
Less than one-quarter (24%) of Aberdeen's office space is currently rated B or above, with 10% achieving A. Knight Frank said.
Matthew Park, office agency partner at Knight Frank in Aberdeen, said: "It seems inevitable there will be some form of legislation coming in Scotland that reflects what the UK Government has sought to do with MEES.
Net-zero targets
"Even in the absence of legislative pressure, many corporate occupiers in Aberdeen have their own net-zero targets and will not consider space with an EPC rating below B.
"Landlords in the city will need to think carefully about their plans if they want to continue to attract occupiers. We already have a number of offices going through major refurbishment projects to bring them up to higher-sustainability criteria."
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