The Scottish Government made a commitment to developing regulations to ensure that all new buildings use zero direct emissions heating (ZDEH) systems. These systems, including heat pumps, electric storage heaters and electric boilers, emit no greenhouse gases when in operation. They are therefore fundamental in reducing emissions from buildings and move Scotland towards its goal of achieving net zero by 2045. 

To assess the impact of the new policy on islands communities, the Scottish Government commissioned research through ClimateXChange. The study looked into the costs and key considerations of installing these types of heating systems on Scottish islands.

Researchers from LCP Delta and Changeworks reviewed literature and interviewed staff from local authorities, housing associations, builders and heating installation and maintenance companies who operate in these areas.

ZDEH systems on islands

The researchers found that many island communities began installing these types of heating systems a decade ago, so there is no negative impact expected from new legislation. This is because in the islands there is no connection to the mains gas network, so installing ZDEH can be more feasible than installing gas boilers.

Local authorities and housing associations are already installing electric heating technologies over fossil fuels alternatives. Moreover, reducing energy consumption is a top priority and so they invest in insulation, air tightness and natural ventilation and light in buildings, which supports ZDEH.

Lessons learned

Lessons from the experience of communities in the islands have already led to improvements in heating systems.

For instance, salt air can make outdoor heating units rusty. To prevent this, it is now standard practice in coastal locations for manufacturers to install air source heat pumps coated with enhanced corrosion protection.

Furthermore, thermal response testing is now conducted on all new ground source heat pumps projects in Orkney, ensuring optimal design. This insight was gathered through a pilot project in a care home in the early 2000s, where the boreholes were too close together, resulting in the ground freezing, and a new ground array having to be installed.

Preferred heating systems

The research also looked into what zero direct emissions heating systems are being used. Electric storage heating and heat pumps emerged as the most common ZDEH technologies across Scottish islands and remote communities.

The choice of system depends on factors such as what specialists are available locally to install and maintain the system, space constraints and building type.

Ground source heat pumps are often cost-effective for large commercial buildings, such as care homes, while air source heat pumps are preferred for smaller commercial and residential buildings and in rural areas with plenty of outdoor space. Meanwhile, storage heaters remain a reliable and affordable option for social housing developments.

Availability challenges

The research also highlighted some challenges. Many of the interviewees believe that the number of companies installing and maintaining these heating systems on Scottish islands and remote areas is insufficient. This is a challenge across Scotland, but can have a higher impact in remote areas.

The additional costs and travel time to these locations might deter some installers, posing a potential challenge to meeting the rising demand for ZDEH systems from upcoming legislation in 2024.


Installing and maintaining ZDEH systems on islands can incur higher costs than in mainland Scotland due to additional expenses such as extra fuel, ferry fares and accommodation for installers travelling to remote areas.

More extreme weather also impacts on costs because it may delay deliveries by ferry, energy demand is higher to keep buildings warm and there are costs associated to coating heat pumps.

For instance, the most popular choice in new buildings, an air source heat pump, is £3,000 to £4,000 more expensive on average on islands than on mainland Scotland. However, considering the full lifecycle of a heating system, the difference in cost between the most expensive ZDEH technologies and fossil fuel-based systems is marginal.


As we look to the future, the research highlights the potential of zero direct emissions heating systems on Scottish islands. The installers interviewed do not expect the new legislation to have a major impact on the heating technologies installed in new buildings in these regions. The study also found that there are no significant cost barriers to adopting these technologies compared to alternative options.

From April 2024, it will be forbidden for new buildings in Scotland to use heating systems that emit more than a negligible amount of direct greenhouse gases when in operation, as per the New Build Heat Standard (NBHS). The Scottish Government wants to make sure this will not negatively impact Scotland’s islands communities.

Based on this ClimateXChange study, together with public consultations and engagement with key stakeholders, the Scottish Government has concluded that the NBHS will not have a disproportionately adverse effect on island communities.

In fact, the transition to these systems on Scottish islands has already been happening for decades and valuable lessons have driven preventive measures in heating technologies. This is an important step towards achieving Scotland’s climate goals.

Related links

CXC project: Zero emissions heating in new buildings across Scottish islands

Scottish Government: New build heat standard 2024 island communities impact assessment