Choosing the right insulation starts with the type of property you are working on. Is it a large commercial property, an older residential home, or a new build?
Depending on the building, each type comes with different construction methods, performance needs, and insulation priorities, from meeting regulations to managing budget or preserving building integrity:
1. Commercial Buildings
Commercial buildings are typically larger and face greater heat loss, along with more stringent building regulations. Insulation in these spaces needs to meet specific demands such as fire safety compliance, acoustic control in open or shared areas, and effective moisture and air management around HVAC systems.
High R-value materials like phenolic boards, PIR, or spray foam are often preferred because they deliver strong thermal performance in thinner profiles, ideal for maximising internal space.
2. Older Residential Homes
Older homes often have limited cavity space, timber floors, and poor air sealing, which makes insulation a bit trickier. Breathable natural materials like wood fibre or sheep’s wool are ideal to prevent moisture build-up and damp issues.
Mineral wool or blown-in cellulose is often used in lofts and wall cavities, while rigid insulation boards can be installed internally if external insulation isn’t permitted due to planning restrictions.
3. New Builds
New-build homes offer more design flexibility, allowing for insulation to be fully integrated from the outset. High-performance materials like PIR or phenolic boards are commonly used across floors, walls, and roofs.
These builds can also incorporate advanced detailing to eliminate thermal bridging, and use insulated panels or breathable membranes to improve airtightness and overall energy efficiency.
Floor, Wall & Roof Insulation - What Works Best?
For suspended timber floors, mineral wool or PIR boards work well when fitted between joists. Solid concrete floors typically use rigid foam boards like PIR or EPS laid under a screed layer. If soundproofing is a priority, opt for dense mineral wool or natural fibre batts, which offer better acoustic insulation.
Cavity walls are often filled with blown-in mineral wool, foam, or polystyrene beads. Solid walls can be insulated externally using PIR or EPS boards, or internally with insulated plasterboard. For enhanced sound performance, mineral wool or natural boards installed internally are effective.
Pitched roofs are commonly insulated with PIR boards placed between or over rafters, while mineral wool offers a more affordable solution. Flat roofs require high-performance boards like PIR or XPS, laid externally in a “warm roof” configuration. For unconverted lofts, mineral wool rolls are cost-effective, whereas converted lofts benefit from PIR boards for better thermal performance.
Residential vs. Commercial Insulation
Residential insulation focuses on comfort, cost-effectiveness, and ease of installation, often using familiar materials like mineral wool and PIR boards, whereas commercial projects may require higher-performance, fire-rated, and acoustically sensitive materials due to scale and regulation.
Tip: For commercial buildings, always consult building regulations early - acoustic and fire requirements are often stricter than in residential settings.
Flat Roof vs. Pitched Roof Insulation
Flat roofs typically need rigid, moisture-resistant boards installed above the structure (warm roof method), while pitched roofs allow for flexible installation between or over rafters, using PIR boards or mineral wool.
Tip: Always ensure proper ventilation with pitched roofs to prevent condensation build-up, especially in older homes.
Internal vs. External Wall Insulation
Internal insulation is ideal when external work isn't possible, but it reduces floor space slightly. External insulation boosts energy performance and protects building fabric but may require planning permission.
Tip: If you're renovating and want minimal disruption indoors, external wall insulation (EWI) can refresh your home’s appearance and improve performance.
Eco-Friendly Insulation Options
Eco-friendly Insulation like sheep’s wool, wood fibre, and cellulose offer breathable, sustainable alternatives with solid performance. They’re ideal for retrofit or green building projects focused on health and low carbon impact.
Tip: Natural insulation works best when paired with breathable membranes and airtight construction to avoid moisture issues and maximise comfort.