Behind Scotland's New Energy-Efficient Building Framework

Scotland is preparing to overhaul how it advises households and businesses on improving energy efficiency, moving beyond the standardised recommendations that have characterised traditional Energy Performance Certificates.

The Scottish Government has appointed AECOM to design a new national framework called the Heat & Energy Efficiency Technical Suitability Assessment (HEETSA), which promises to deliver building-specific guidance on suitable improvements and transitions to low-carbon heating.

The infrastructure consultancy is set to work until spring 2026 to develop an approach that addresses what officials see as a critical weakness in current EPCs: their failure to reflect the technical realities of Scotland's diverse building stock.

Currently, EPC ratings place Scotland's building stock among the least energy efficient in Europe, with around 70% of all homes rated C or D and with a further 15% with the lowest ratings of E, F or G. As such, heating buildings efficiently is a problem in the northernmost nation of the UK.

The Scottish Government hopes that HEETSA will go some distance towards helping to improve the performance of its built environment.

"HEETSA has the potential to be a significant step in how Scotland supports people to make their homes and shared spaces more energy efficient," says David Ross, Regional Director at AECOM.

A reassessment of energy ratings

AECOM's work on this project will involve a comprehensive review of how retrofit assessments currently operate across the country, both with regards to residential and commercial buildings.

The review will, in essence, look to identify where existing advice proves effective and what kinds of improvements are needed to ensure future recommendations achieve consistency and reliability.

A key component of the framework will establish clear criteria for who can conduct HEETSA assessments, including the qualifications, training, experience and standards that assessors will need to meet.

Another central part of the project will be the development of clearer presentation methods, which should enable policymakers to transform HEETSA into what the Scottish Government describes as a straightforward tool for property owners to ensure that assessments are of the "highest quality".

How HEETSA could address Scotland's built environment emissions

The initiative forms part of Scotland's wider Heat in Buildings Programme, which combines advice on retrofitting with funding opportunities and planned future regulations.

Buildings currently account for approximately one-fifth of Scotland's emissions, making the sector a crucial focus as the country works toward its legally binding 2045 net zero target.

For stakeholders like David, the practicality of the project is its most important aspect.

"It's an opportunity to give property owners advice they can genuinely trust, tailored to their building, clear in its recommendations and grounded in the realities of Scotland's diverse housing stock," he says.

Others, however, have not been so enthusiastic about the introduction of more bureaucracy to Scotland's construction processes.

Matthew Clubb, Director of mwclubb, an Aberdeen-based architectural design firm, is a strong proponent of sustainable retrofitting but believes that the introduction of HEETSA might hinder more than it helps.

"It has been frustrating to see the Scottish Government releasing yet another consultation, on a process, which I fear, they still do not fully understand," Matthew writes on LinkedIn.

"There are various references in the consultation which demonstrate this lack of understanding which leads me to believe there is a lack of retrofit practitioners, (people who deliver retrofit day-in day-out) on their steering panels."

"HEETSA is a proposal to develop a new methodology for determining the most appropriate solutions for the home, for insulation and zero-emissions heating," he continues.

"The claim is that a retrofit assessment process risks recommending measures that are not suitable for the building or the occupants.

"It aims to build retrofit design knowledge into the assessment of options, which warrants merit, but denies the rest of the process exists or that multiple disciplines and roles are involved in the overall process."

Building on previous experience

AECOM brings relevant experience to the project, having previously supported the Scottish Government in creating Scotland's first national heat map.

That earlier work, which identified areas of highest heat demand and potential renewable heat development, was piloted in three councils before national rollout and has since helped local authorities plan more effectively for cleaner heating systems.

For the HEETSA project, AECOM is leading a team that includes architecture and consultancy partners Four Walls Consultants, Spruce Retrofit Consulting, Carbon Futures and Energy Conscious Design Architects.

The team will also pull on academic expertise from Glasgow Caledonian and Robert Gordon Universities, as well as Dr Richard Atkins, Chair of the Royal Incorporation of Architects in Scotland.

A bid to boost consumer confidence in construction

The Scottish Government's move to develop HEETSA reflects broader concerns about consumer confidence in the retrofit market.

By providing more tailored and practical recommendations, the nation's ministers hope to address scepticism that has emerged around generic energy efficiency advice that fails to account for building-specific constraints and opportunities.

"We want to avoid any potential unintended consequences when installing energy efficiency measures and to strengthen confidence in assessments," explains Alasdair Allan, Scottish Minister for Climate Action.

Whether the new framework succeeds in building that confidence will depend substantially on the quality of assessor training and the practicality of recommendations once the system launches beyond spring 2026.