Making Scotland’s net-zero ambitions real

As Scotland’s Climate Week draws to a close, one thing is clear: reaching net zero will depend not only on the buildings we build next, but on the homes, workplaces, schools and community spaces already in use today.

Scotland’s goal is to reach net zero by 2045. For our buildings, that means using less energy, moving away from fossil-fuel heating and making sure the change works for households, businesses and communities. Retrofit will be a big part of that.

At Sisalwool, we see retrofit as more than a technical challenge. Done well, it is a chance to create warmer, healthier and more resilient buildings, while making better choices about the materials we use and embracing the circular economy

The buildings we already have

Most of the buildings that will still be in use in 2045 have already been built. That means we cannot rely on new homes alone to reach net zero.

Scotland faces a major change in the way its homes and public buildings are heated and improved. Around 1.9 million homes and 13,000 public buildings are expected to move to clean-heating systems, such as heat pumps and heat networks, by 2045. At the same time, those buildings need to use less energy to stay warm.

That is where retrofit comes in.

Put simply, retrofit means improving an existing building. It could involve insulating a roof, wall or floor; cutting down draughts; upgrading windows; improving ventilation; changing the heating system; or making a series of well-planned improvements over time.

The best results come when those improvements are planned together. A building works as a system. The roof, walls, floors, windows, ventilation and heating all affect one another. Understanding those links is the difference between a quick upgrade and a long-term improvement that works well.

Start by making buildings work better

Much of the future conversation will focus on clean heat…and rightly so. Heat pumps, heat networks and other low-carbon technologies will be important if Scotland is to move away from fossil-fuel heating.

But new heating technology cannot do all the work on its own.

A home that loses heat quickly through its roof, walls, floors and gaps will need more energy to stay comfortable, whatever heating system it uses. Improving insulation and reducing heat loss before, or alongside, a heating upgrade can lower energy demand and help low-carbon heating perform more effectively.

This matters particularly in Scotland, where many properties are older, traditionally built or have specific moisture-management needs. The right solution will always depend on the building, but a good plan should consider:

• Where and how the property loses heat
• Its age, construction and current condition
• Ventilation and indoor air quality
• How moisture moves through the building
• The best order for making improvements
• The long-term suitability of the materials used

The Scottish Government recognises that retrofit measures such as loft and wall insulation can reduce heating demand, help protect people from cold weather and support more comfortable indoor temperatures during hotter periods.

Retrofit has to feel achievable

Climate targets matter, but so do people’s homes, budgets and day-to-day decisions. For retrofit to happen at the scale Scotland needs, it has to feel realistic, not like a specialist project only available to a few.

That means clearer, independent advice; skilled installers and professionals; practical guidance for homeowners and landlords; and funding that helps people move from intention to action.

During Climate Week, we looked at some of the support already available. For homeowners, Home Energy Scotland can provide advice on grants and interest-free loans for eligible insulation, energy-efficiency and clean-heating measures. Businesses can access free support through Business Energy Scotland, with qualifying SMEs potentially able to use the Scottish Government’s SME Loan Scheme for energy-saving improvements.

Funding will not remove every barrier, but it can make an important difference. The best place to start is with good advice: understand the building, make a sensible plan and avoid rushing into one-off improvements.

The materials we choose matter too

Lower-energy buildings are only part of the picture. The materials we choose to improve them matter too.

The construction sector has a responsibility to reduce waste, use resources carefully and think about the whole life of the products it specifies. That is why circular-economy thinking matters alongside energy efficiency.

Earlier this week, we explored how Sisalwool uses reclaimed coffee sacks, textile-industry offcuts and sheep’s wool in its natural-fibre insulation. Rather than treating these materials as waste, we seek to give them a valuable second life in products that help create warmer buildings.

There is no single right material for every building. Good retrofit is always about choosing the right solution for the property. But it is worth asking better questions: Where have the materials come from? What resources do they use? Can they support breathable construction? How will they perform in use? And what happens to them over time?

For traditional and moisture-sensitive buildings in particular, natural-fibre insulation can be a useful option where a breathable, moisture-managing construction is needed. It can help reduce heat loss while supporting the way these buildings were designed to work.

A practical route to net zero

Scotland’s Climate Week is about more than one week of activity. It is a chance to recognise progress, share ideas and encourage action in communities, businesses and organisations across the country.

There will not be one route to net zero for every home or building. Some projects will begin with loft insulation. Others may involve a full renovation, a new heating system, improved ventilation or a carefully planned deep retrofit. Some will happen all at once; others will take place step by step.

What matters is moving in the right direction:

• Reducing avoidable heat loss
• Improving comfort and energy efficiency
• Planning heating upgrades as part of the whole building
• Using funding and impartial advice where available
• Choosing durable, suitable materials
• Keeping valuable resources in use for longer

Scotland’s 2045 net-zero target is ambitious. But it becomes more achievable through practical choices: reducing heat loss, planning improvements properly and choosing materials that are right for the building.

At Sisalwool, we are proud to have supported Scotland’s Climate Week and the wider conversation around better retrofit. By improving the buildings we already have, and thinking carefully about both energy performance and materials, we can create homes and spaces that are warmer, lower energy and better prepared for the future.