Tackling Energy Inefficiency in Homes: Inspiration from Scotland

20 Dec 2023

Cornerstone Climate

Scotland takes a significant leap in sustainable building practices by considering the adoption of the Passivhaus standard for new homes.

Cornerstone’s David Welsh examines the implications of this move on the UK’s net zero goals and the future of energy-efficient living.


Energy efficient housing is a key element of the transition to net zero. The primary indication of such efficiency for home buyers is an energy performance certificate.

However, the accuracy of such certificates has long been queried and enforcement is often patchy at best. How, then, do we make progress in practical terms?

In Scotland, an attempt is underway to make real progress with making new build homes more energy efficient. The push started with the introduction by a Labour MSP, Alex Rowley, of the proposed Domestic Building Environmental Standards (Scotland) Bill. The proposal was lodged with the Scottish Parliament on 16 November 2022 after a period of consultation, and Mr Rowley was given the right to introduce his member’s bill.

The Scottish Government made a statement under rule 9.14.13 of the standing orders of the Scottish Parliament. The effect of a statement under that rule is that the member’s bill is not permitted to proceed because the Scottish Government intends to introduce its own legislation (within a period of 2 years from the date of the statement) to give effect to the final proposal. Put short, therefore, the Scottish Government indicated that it would bring forward its own government bill which would achieve the same legislative purpose as Alex Rowley’s proposed bill.

We are now a year into that 2-year period and it perhaps provides a useful opportunity to consider what the Scottish Government’s bill might look like when it is published within the next year. That is particularly the case when one considers the new change at paragraph 164 of the National Planning Policy Framework in England, requiring planning authorities to give significant weight to supporting energy efficiency.

The driving force behind Mr Rowley’s proposal was the introduction of the ‘gold standard’ Passivhaus standard (or at least a Scottish equivalent) for all new build housing in Scotland. Changes of that nature in Scotland are likely to be effected by amending existing building regulations and standards.

The Passivhaus standard focuses on a number of key principles:

  • Insulation (far greater than typically used in the UK at the moment);
  • Triple glazed windows and insulated frames;
  • Airtight buildings (approximately 20 times more than current standards); and
  • Heat recovering and mechanical ventilation.

One of the primary advantages of a house built to the Passivhaus standard is that it has a significantly reduced need for heating. Indeed, the principles are designed so that a conventional heating system is not required at all and, at least in theory, heating is instead provided by way of the ventilation system with hot water provided by way of an air source heat pump or similar technology.

A number of Passivhaus developments have been granted permission and have been completed throughout the UK. A large residential development (around 72 houses) was completed in Plymouth with others in Fife, Dundee and the Trossachs National Park. A housing association operating in Essex and Norfolk reported that the number of properties in rent arears had become negligible in its Passivhaus-compliant properties because tenants were spending so little on energy that they were not being forced to choose between heating and paying their rent. So it is clear that energy efficiency has direct as well as indirect benefits.

If the UK is to reach its emissions targets and transition towards net zero, the adoption of the Passivhaus standard for new build homes would be a good place to start. Whilst there is undoubtedly a place for schemes such as retrofitting insulation to older properties – and that is to be welcomed and encouraged – there is clear and tangible benefit in making sure that houses being built now are built to the higher standard, making it unnecessary to revisit them for retrofitting in the future.

We wait to see exactly how the Scottish Government tackles the issue with its draft bill. The bill will inevitably be the subject of debate and consultation, but it seems likely that the requirements will be of prescribed outcome and not by way of any particular prescribed method of achieving it. It seems likely, for example, that airtightness will be a key factor but it will likely be left to developers to determine how best to achieve that.

If that is the mechanism that is adopted in the legislation, enforcement will be key. Unlike the current EPC procedure, it would almost certainly require each individual building to be assessed once completed rather than assessing the energy efficiency of a building by reference to a model or estimate by reference only to its design. That is how the member’s bill was intended to operate and we wait to see if it finds its way into the government bill.

There are difficulties with the Passivhaus standard: higher upfront costs, for example. It may be, therefore, that there is a Scottish equivalent standard which seeks to find a balance. Whatever happens, Scotland has taken the first steps to make progress with building standards and that is to be encouraged and supported.

David Welsh specialises in public and commercial law and has particular experience in relation to taxation and the use of trusts. Since being called to the bar in 2017, David has appeared in courts at all levels, including before a full bench of the UK Supreme Court and a full bench of the Court of Justice of the European Union. David has a busy public law practice, including high-profile constitutional litigation.

Learn more about his practise here.