PIR, EPS, XPS or mineral wool: comparing the cost of a complete insulation order

Each quotation column should cover the same part of the building.

Record the rooms or roof areas, measured quantities and requirements supplied by the designer. Identify the exact product and selected thickness for each option. A label such as “polystyrene” or “mineral wool” is not sufficient to distinguish materials intended for different applications in the cost schedule.

A quotation may use a price per board, pack, square metre or cubic metre. Converting volume to area requires the thickness in metres. As a geometric example, 1 m³ of a uniform 0.10 m layer covers 10 m²; at 0.15 m it covers approximately 6.67 m². This converts quantities rather than comparing thermal performance.

For a price per board, check the dimensions and the area used for billing. Where edges are profiled, clarify how the supplier states the coverage. Keep the original sales unit in a separate column so that the quoted amount can still be reconstructed after conversion.

For calculation only, suppose the order requirement is 82 m² and each pack contains 5 m². If only whole packs are sold, the order needs 17 packs, or 85 m². Use 85 m² in the cost calculation. The additional 3 m² in this example comes entirely from rounding to complete packs.

Separate pack rounding from the allowance for cutting. The installation quantity depends on the area geometry and board format. If the contractor’s requirement already includes cutting losses, adding another general percentage can duplicate that allowance. Record who established the quantity and the basis used.

List the fixings, adhesives, tapes and additional layers required by the chosen construction. Different materials do not necessarily need the same accessories. Use the selected assembly and installation instructions to define the list. Mark an empty entry as “not applicable” or “to be clarified”, rather than silently assigning zero cost.

When the thickness changes, ask the contractor whether details also change, such as fixing lengths, termination height or flashing work. Separate the insulation cost from work needed to adapt the surrounding construction. This makes additional scope visible when comparing a less expensive board with the original quotation.

For transport, record the delivery address, number of delivery stages and agreed unloading arrangements. Check which services the price includes. If one quotation provides a single delivery and another allows two visits, show that difference before comparing their totals.

Use the same price basis throughout: excluding or including tax, the currency and quotation validity date. Confirm any return arrangements for unused packs before ordering. Do not deduct the anticipated value of leftovers unless the supplier has agreed to accept them.

Send suppliers a list of missing information tied to specific line items. Ask for a revised schedule showing quantity, unit and the scope included in each price. Bring verbal clarifications about delivery or accessories into that same document before selecting an option.

Keep the completed comparison with the accepted technical specification. Compare costs between options suitable for the intended application. If the cheapest package does not meet the design requirements, return to the technical review. Adding up prices does not establish that the insulation is suitable for the building.