How to compare wall and roof sandwich panel prices per square metre

Check the quotation date and how long its terms are valid. A published price list can start the discussion, but confirm the scope and delivery date when ordering. A unit price for one batch may not extend to every length. Even similar stock panels can carry different prices because of the dimensions available.

A roof panel has a profile and junction details designed for drainage and the loads on the roof slope. Laying a wall panel across purlins does not make it an equivalent covering. Compare the design requirements with the data for the specific panel, including loads, facing thicknesses and installation conditions.

Apply the same check to the core. Compare PIR, EPS and mineral wool against the function required. Thermal performance, weight and documented fire performance can call for different assemblies at the same thickness. Assess the complete wall or roof before substituting a material in the estimate.

The following rates are hypothetical and exclude VAT. They illustrate the calculation rather than current offers or market averages. Unit rates are rounded for display. The line totals use the unrounded rates. Check the specification of each item before placing an order.

The weighted average is approximately €32.61 excluding VAT per square metre purchased. It describes this mix of panels only. Installation is extra. Keep the two lines separate so you can track changes in quantities and scope.

The same panel can be priced by linear metre, square metre or piece. With an effective cover width of 1.10 m, a 5 m panel covers 5.5 m². That example uses an assumed module. Overall width can differ from cover width, so ask which width is used for invoicing.

The area ordered includes pieces lost when cutting. Simply subtracting openings from wall length times height can underestimate what you need. The panel layout determines whether an offcut can be reused. A piece-by-piece schedule gives a better basis for costing than an arbitrary waste percentage.

Take flashings, fixings, tapes and seals from the junction details. List the right quantity in pieces, metres or packs for each item. Distinguish the price of a box of screws from the price of a single screw. For flashings, compare length, developed width and coating as well as price.

Add freight, unloading and installation. A single delivery can account for a substantial cost per square metre on a small job. Long panels may require specific handling equipment. The quotation should identify who provides storage space and removes waste, since both still need organising even if omitted from the price.

With the whole scope listed, compare the differences. Changes to thickness, coating or fixing arrangements can affect the building in service. Extra insulation needed next year, difficult repairs to an unusual batch, or a flashing left inaccessible can all have consequences beyond the original material price.

Record tax assumptions separately and compare all amounts consistently either including or excluding VAT. When the design changes, update the individual quantities and items as well as the total. The resulting table gives you a project-specific reference for assessing a supplier’s revised proposal and identifying what actually changes the budget.