The Heat Networks (Scotland) Bill

Gavin Mowat ,
1 Sep 2020

Gavin Mowat, our Policy Adviser, gave evidence to the Scottish Parliament’s Economy, Energy and Fair Work Committee today on the Heat Networks (Scotland) Bill. Here he updates us on the key issues.


The Heat Networks (Scotland) Bill aims to encourage greater use of heat networks in Scotland. Heat networks are made up of insulated pipes and heat generation systems which make heat. This can be in the form of hot water or steam. This will help reduce emissions from homes and other buildings.

At SLE, we believe that viability is key. Heat networks require considerable up front capital investment and lengthy periods of up to 20 plus years to see returns on those investments. With energy efficiency in new housing likely to extent those periods further, it is important regulation de-risks investment opportunities in the sector, particularly if schemes are to become viable in rural areas which typically have lower demand and marginal land values.

We do not think relying on Energy Performance Certificate (EPC) data to predict demand for heat is entirely sound. An EPC is a rating scheme to summarise the energy efficiency of a building. An EPC is needed when a property is built, rented or sold. We have consistently called for a review of the EPC methodology which we consider to be flawed – particularly with respect to existing housing stock. Our members experience shows that when costly upgrades are made to properties these are often met with insignificant increases in EPC efficiency, if any at all. This is largely due to the reliance on using modelled energy consumption data rather than actual measured data.

So, if we start assessing demand based on a flawed system, we are concerned that District Heating systems could be under or over sized resulting in people being overcharged or indeed not being supplied with adequate heat.

We suggest more emphasis could be placed on the environmental impact rating which is a measure of a home’s impact on the environment in terms of carbon dioxide emissions. The higher the rating, the less impact it has on the environment. This rating is based on the performance of the building and its fixed services (such as heating and lighting). EPCs could be supplementary to this.