A Scottish council has paused a requirement for its new housing to meet the Passivhaus sustainability standard, amid concerns over high costs.
Last week, members of Midlothian Council backed a motion to pause the pursuit of Passivhaus compliance in future housing developments until the council could better consider its costs and benefits.
The decision does not apply to schemes that are currently under construction.
Passivhaus is an international design standard for highly energy-efficient buildings that ensure a low level of fluctuation in temperature. Passivhaus buildings require less heating and cooling, and therefore emit less carbon and are not as costly to operate as regular buildings.
Stuart McKenzie, the Scottish National Party-led council’s cabinet member for housing, suggested a rethink on the commitment to Passivhaus, “given the variance between what we expected it to cost and what it actually costs”.
Midlothian’s Net Zero Housing Design Guide, published in March 2022, specifies the Passivhaus standard for new council buildings from 2022.
On the previous decision to pursue Passivhaus certification, McKenzie said “I think at the time we made the right decision for the right reasons”. But he proposed pausing the policy “so that we can better understand the cost variance and why that is coming out significantly more expensive”.
McKenzie added: “It could be that the way forward is that we continue with Passivhaus and that we continue with the additional cost burden. Or it could be that we find another methodology which provides houses which are just as warm.”
A report to the meeting set out a comparison of costs on sites that did and did not specify the Passivhaus standard. The three sites with Passivhaus had a cost per unit of between £324,000 and £341.456. At those where Passivhaus was not specified, the cost per unit was between £182,866 and £302,500.
But the report acknowledges that “the assessment of the specific impact of building to a Passivhaus standard on cost is difficult to ascertain” due to factors including a volatile market and high inflation, adding that “a direct comparison is not possible”.
McKenzie’s motion was seconded by SNP councillor Stephen Curran. He called for an analysis of the impact of Passivhaus, saying it was “hard to believe” a claim that it would reduce energy bills at one local development by 80 per cent.
The council’s executive director of place, Kevin Anderson, agreed to provide such an analysis.
He pointed out that the Passivhaus commitment was “one of the avenues” through which the council was planning to reach net zero by 2030.
Anderson said: “Clearly there is [an] implication in terms of the net-zero commitment for the council, if we’re not going to deliver that solution for the housing stock, although, as has been inferred, there are other avenues available – which we will, and are, delivering in other sites where Passivhaus doesn’t seem to be the solution.”