Insulation Calculator
Pick the insulation material (EPS, XPS, rock wool) and the area to insulate — see a rough area with 5% waste allowance and the required number of packages based on common package-coverage rates.
We typically respond within 24 hours.
Let's determine the right insulation material and thickness together based on your building's real energy performance targetThis is a rough illustration using a common reference package-coverage rate for the selected material; actual package content varies by board thickness, brand, and product line. The required thickness needs a separate energy performance certificate calculation.
How is the required insulation quantity calculated?
Insulation quantity is calculated by dividing the area to be insulated (m²) by the area a single package covers. A waste allowance of around 5% is typically added to the calculated area for cutting loss and corner/detail work.
The tool above uses a common package-coverage rate for your selected material to show the area with a waste allowance, plus the required number of packages.
Common package-coverage rates by material type
EPS (expanded polystyrene) insulation boards typically cover about 3 m² per package; XPS (extruded polystyrene) boards, being denser, cover about 2.88 m² per package; rock wool (mineral wool) boards can cover about 4 m² per package.
This tool uses a common reference rate for each material — actual package content varies by board thickness, brand, and product line.
Why material selection isn't just about m²
The choice between EPS, XPS and rock wool shouldn't be based on coverage rate alone; it should also factor in performance criteria like thermal conductivity (λ value), fire resistance, vapor permeability, and moisture resistance. This tool only offers a rough quantity estimate — material selection should be evaluated separately based on the project's energy performance certificate calculation and building physics requirements.
Let's determine the right insulation material and thickness together based on your building's real energy performance target.
Contact usFrequently Asked Questions
How is the required insulation quantity calculated?
Simple formula: Number of Packages = (Area (m²) × 1.05) ÷ Package Coverage (m²/package). For example, a 40 m² facade insulated with EPS covering 3 m² per package needs (40 × 1.05) ÷ 3 = 14 packages.
Why is the waste allowance for insulation lower than for other materials?
Insulation boards are usually applied with straight cuts and don't require pattern alignment like tiles, so a lower waste allowance like 5% is sufficient. Complex facade details (window surrounds, corner profiles) can push this rate up slightly.
What is the difference between EPS, XPS and rock wool?
EPS and XPS are polystyrene-based, lightweight and economical insulation materials; XPS is denser and has higher moisture resistance. Rock wool (mineral wool) is a natural mineral-based material with superior fire resistance and sound insulation. The choice depends on budget, fire regulation requirements, and application point.
Does this tool also calculate the insulation thickness?
No. The tool only calculates the required quantity for the selected package; the required insulation thickness is a separate engineering calculation based on the building's energy performance certificate, climate zone, and thermal conductivity target.