Priority Places for Insulation: Mapping Northern Ireland's Home Insulation Needs

Introduction

Improving the energy efficiency of a home reduces energy bills, improves health outcomes and provides a warmer home for people. With high energy prices and the need to progress net zero ambitions, there has been increased attention on the state of the UK’s housing stock, which is among the oldest and ‘leakiest’ in Europe. Within Northern Ireland, a fifth of homes had no wall insulation in 2016. Northern Ireland has always experienced high levels of fuel poverty with 24% of households estimated to be living in fuel poverty in 2021. Additionally, Northern Ireland faces a unique problem of depending on oil heating with more than two-thirds of households relying on oil as their main fuel source, subjecting them to fluctuating oil prices.

In a bid to improve the energy efficiency of homes and reduce fuel poverty, there is currently a One-Stop Shop for energy advice alongside the Northern Ireland Sustainable Energy programme which collects funds from electricity customers to help vulnerable households afford energy efficiency improvements. 

Although improving Northern Ireland’s housing stock is a national challenge, it will be tackled home by home and street by street. The number of homes with poor insulation and household circumstances such as the level of fuel poverty, health and overall age of the population vary between different places. Understanding these differences is crucial for national and local governments to aid decision-making on targeting support and services to the people who need it most. To support this, Which? has collated and analysed data on a range of factors that determine the need for insulation and created the Priority Places for Insulation Index, which identifies areas likely to be in the most urgent need of insulation.

Methodology

The Priority Places for Insulation Index is a composite index constructed using data from eight different indicators, where each has specific metrics of measurement. Five of these indicators focus on the quality of housing stock and are created using data from Energy Performance Certificates (EPCs). These are the average level of all types of wall, loft/roof and floor insulation, and the proportion of properties that are flats. We include property type  in addition to levels of insulation because flats and apartments need fewer measures to be adequately insulated. 

The three remaining indicators cover household characteristics and comprise socio-demographic and health circumstances of households in a local area. We include income levels as a proxy for fuel poverty, due to data not being available at a local level, as households in fuel poverty will benefit more from having their property insulated. We include the proportion of households aged over 65 because the elderly face worse health consequences from living in a cold home, and similarly we include the incidence of health conditions such as cardiovascular and respiratory diseases as these are worsened by living in a cold home.

The index has been constructed individually for each of the four UK nations (England, Wales, Scotland and Northern Ireland) and on three geographical levels. For Northern Ireland, these are:

• Super Output Areas, which we refer to as local areas
• Current Westminster Parliamentary Constituencies
• Local Government District

Further details on the methodology can be found in the technical annex.

Identifying the priority places for insulation

Figure 1: Proportion of priority places which are urban are highest in Northern Ireland

These urban priority places are primarily concentrated in Belfast West and North, although there are also pockets of priority places in Belfast South as well near Willowfield (Image 1). These priority places can be characterised by low levels of properties with insulation, an ageing population suffering from health issues and lower levels of income. 

Image 1

Further concentration of urban priority places can also be found throughout the Foyle area (Image 2). The city itself primarily consists of older stone houses and the community is historically deprived, with its people suffering from lower incomes and worse health conditions.

Image 2

Although the priority places are primarily located in urban areas, there are still a few in more rural regions as well. There are also areas of concern in Limavady, a rural market town with properties that have poorly insulated walls and floors, and an ageing community experiencing high levels of respiratory and cardiovascular diseases.

Elsewhere, the local level data allows us to identify communities with high levels of need within constituencies and regions that generally have a lower prevalence of priority areas. For example, in East Antrim, there are clusters of priority places in two of its coastal towns (Image 3): Larne, an industrial town characterised by poorly insulated houses and tower blocks coupled with a high proportion of low-income population; and Carrickfergus, among the oldest towns in Northern Ireland, thus possessing an ageing housing stock which is hard-to-treat.

Image 3

Westminster constituencies

The index also ranks the need for insulation by current Westminster constituency. Figure 2 displays all 18 constituencies from the highest to the lowest need, along with the indicators that are more dominant in driving the need. Indicators designated as ‘Very High Priority’ mean that the constituency is in the bottom 9th and 10th deciles for that indicator, “High Priority” meaning they are in the bottom 7th and 8th deciles, and so on.

Figure 2: Heatmap of need for insulation in Westminster constituencies

Supply of insulation installers

Alongside identifying areas most in need of insulation, it is crucial to ensure there is an adequate availability of installers available to service those areas. Using our methodology, we are able to identify installation firms with an online presence and that specify insulation services on the sites that we pulled information from. A caveat is that for Northern Ireland, we were unable to capture cross-border availability from suppliers who are located in the Republic.

The median number of installers in Northern Ireland is only two firms available per 100,000 people, or equivalently, one firm to service 19,231 households which is the lowest in the UK. While the lack of installers is a national problem, this is more pronounced in certain constituencies than others. Figure 3 illustrates the relative paucity of firms in constituencies in the southern region of Northern Ireland and also in some areas further north such as Foyle and East Antrim.

Figure 3: Supply of insulation installation firms is worse in some constituencies

Combining the data on supply with the need for insulation, we find that there are supply issues in the areas with a high concentration of priority places such as Belfast and Foyle. Although the lack of installers clearly affects numerous constituencies, any efforts to improve the supply chain should be prioritised in areas with a more urgent need for insulation.

In the retrofit market, certification schemes play an important role in enhancing consumer confidence by ensuring adherence to industry standards and providing methods of redress when issues arise. Therefore, we only categorise suppliers as certified if they are registered with certification schemes that we are confident provide adequate consumer protection. These schemes include TrustMark, Insulation Assurance Authority, and Which? Trusted Traders. 

When considering only certified installers, this reduces the median number of firms in Northern Ireland to one per 100,000 people, equivalent to one firm per 38,461 households, highlighting the importance of existing installers being certified where there is already a big shortage in suppliers.

Conclusion

Our research reveals that priority places for insulation are mostly concentrated in the urban areas, specifically in Belfast and Foyle. We also found pockets of priority places in East Antrim (for example, in Larne and Carrickfergus) despite the region being of lower priority overall. Beyond the urban concentration, there are also priority places in smaller rural towns such as Limavaldy. 

In addition to recognising the need for insulation, the availability of qualified insulation installers is critical in improving the energy efficiency of homes in Northern Ireland. Acknowledging the important role of government at all levels in supporting the recruitment and retraining of installers, our research highlights the relatively low levels of installation firms in the constituencies with high concentration of priority places. 

We hope that the collation of this data into a single index will prove to be a useful tool for the Northern Irish Government, policymakers, local government and others trying to support consumers in improving the energy efficiency of their homes.