Insulation Improvement

Please note: This article is for educational purposes only. Always consult a qualified installer or building engineer before making any changes to your building’s insulation.

Thermal insulation prevents unwanted heat transfer in and out of buildings, making indoor spaces more comfortable and energy efficient. Improving insulation before investing in more expensive interventions — known as the fabric-first approach — has been central to net-zero transformation policies and is one of the most cost-effective steps a business can take.

Contents

1. What is Insulation and Who Benefits?
2. Main Elements to Insulate
   1. Roofs
   2. Walls
   3. Pipes and Tanks
   4. Windows
   5. Floors
3. Potential Impacts
4. Important Considerations

What is Insulation and Who Benefits?

Thermal insulation retains heated or cooled air inside a building, reducing the energy needed to maintain comfortable indoor temperatures. Businesses across various sectors, particularly those with poorly insulated buildings or high energy demand, stand to gain significantly from insulation improvements. The fabric-first approach prioritises reducing heat losses through the building envelope before installing more expensive technologies such as heat pumps or air-to-air heat pumps.

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Main Elements to Insulate

Roofs

Heat rises and escapes through the roof if it is not insulated. Insulation can be installed below or inside the roof structure, between and over joists to create a cold roof space. Alternatively, a warm roof system has insulation installed between the tiles and rafters on a pitched roof, creating a thermal barrier between the roof and external air.

Walls

Cavity walls can be insulated by drilling holes in the outer leaf and injecting insulation beads or foam. Solid walls can be insulated from either the inside or outside of the property. External wall insulation is less disruptive and loses no internal space. Internal wall insulation requires more substantial refitting but preserves thermal mass — the capacity of the wall to absorb and store heat energy.

Pipes and Tanks

Large savings can be made by insulating heating pipework and water storage tanks using pipe insulation or lagging jackets. This is particularly relevant for businesses with centralised hot water systems where distribution losses can be significant.

Windows

Secondary glazing, insulated curtains, and sealing gaps will significantly reduce heat loss through windows. These are often low-cost interventions that can be implemented quickly with minimal disruption to business operations.

Floors

Solid floors can be insulated using rigid boards or quilts installed underneath, with no ongoing maintenance requirements once fitted.

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Potential Impacts

• Energy Savings: Proper insulation cuts heating and cooling costs by 10–40% by preventing heat loss through the building fabric.
• Lower Emissions: Less energy wasted on heating means lower carbon emissions and enables cleaner heating systems to operate more efficiently.
• Improved Comfort: Insulation provides more stable indoor temperatures and fewer draughts throughout the year.
• Compliance: Insulation upgrades may improve commercial Energy Performance Certificate (EPC) ratings, which increasingly affect lease eligibility and regulatory compliance.
• Enhanced Asset Value: Improved insulation increases property value and marketability.
• Noise Reduction: Insulation in walls and floors absorbs sound, reducing noise transmission between spaces.

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Important Considerations

• When selecting insulation materials, the R-value and U-value are crucial. The R-value measures heat resistance — higher values indicate better insulation. The U-value represents thermal conductivity — lower values indicate superior insulation performance.
• The ventilation and breathability of insulation should always be considered. Breathable insulation products allow moisture to move through walls, reducing the risk of condensation and damp.
• Insulation upgrades must comply with building regulations covering fire safety, insulation minimums, and other requirements.
• Loft insulation may compress over time, reducing effectiveness. Regular checks and topping up are advised.
• Wall insulation works best when some internal ventilation is still maintained to prevent moisture build-up.

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