Loft Insulation Calculator
Estimate loft insulation coverage and roll quantities using loft area, target depth and manufacturer-stated roll coverage.
Typical use: Mineral-wool loft insulation rolls, top-up layers and basic buying-quantity planning
Using this calculator
Open the interactive calculator to enter your project measurements and adjust the available settings. Review the calculated quantity and buying units before ordering materials. Check product coverage, pack sizes and installation guidance with the manufacturer or supplier.
Planning and practical guidance
Home Energy Efficiency Checklist: What to Improve First
Work through fabric, insulation, heating, controls, lighting and renewable-energy opportunities in a sensible order.
- Start with obvious heat-loss and comfort issues: draughts, poorly sealed doors or windows, missing insulation and uncontrolled heating.
- Check the loft insulation depth and condition, making sure ventilation routes and eaves are not blocked.
- Review walls, floors, windows and doors to understand which parts of the building fabric are likely to be losing the most heat.
- Check the heating system, boiler or heat-pump controls, thermostat settings and heating schedule before assuming the whole appliance needs replacing.
Landlord Property Energy Improvement Checklist
A practical property-by-property checklist for improving comfort, reducing energy demand and planning future EPC-related works.
- Record the current EPC, heating system, glazing, insulation and any known maintenance defects before planning upgrades.
- Resolve damp causes, leaks, failed seals and ventilation problems before carrying out cosmetic work or adding insulation.
- Review loft, wall and floor insulation opportunities and identify straightforward draught-proofing measures.
- Check boiler or heat-pump condition, heating controls, thermostat location and whether occupants can control rooms sensibly.
Loft Insulation Explained: Depth, Ventilation, Storage & Common Mistakes
Plan loft-insulation improvements without blocking eaves ventilation, compressing insulation under boards or ignoring electrics and moisture problems.
- Inspect the loft before adding insulation. Check for leaks, condensation, damaged roof coverings, unsafe wiring or pest problems that should be resolved first.
- Measure existing insulation depth in several locations because older lofts are often uneven or partly compressed.
- Choose insulation suitable for the roof/ceiling construction and follow the manufacturer’s coverage and installation instructions.
- Maintain required ventilation at eaves and other designed openings; do not push insulation hard into the roof edge if that blocks airflow.