How to compare wall and roof panel quotations for a complete building envelope

Give every rate a unit and a quantity. Lengths and piece counts help check the total more reliably than façade area alone. Establish whether the panels will be made to the schedule or supplied from stock. Record quotation validity and expected lead time; a general price list supplies neither.

Roof panels are profiled and jointed to suit the roof slope and shed water. Wall panels may use different profiles and joints. Identical core thickness does not make them the same product. Fixing quantities, flashings, installation plant and access may also differ.

Keep the two assemblies separate in the estimate. Measure the roof along the slope and include its closures. On the walls allow for openings and the width of final strips. Add wall-to-roof junctions separately. This reveals whether a higher panel rate reduces another operation or needs additional parts.

Assume 210 m² of wall panels and 165 m² of roofing. This is a budget exercise, not an offer. Both variants must first be suitable for the same project. All figures exclude VAT. Unit rates and totals are shown in euros, rounded separately after conversion.

The difference is €618.70 excluding VAT. It does not yet establish which finished envelope costs less. Add accessories, delivery and installation.

Now allow €2,015.99 for accessories and logistics in A and €1,483.03 in B, excluding VAT. The totals rise to about €14,973.97 and €15,059.70. On the unrounded figures the gap is only about €85.74. These assumptions illustrate the comparison method; they are not catalogue prices.

Track down the reason for the difference in extras. Do both offers include the same seals and flashings? Does each include unloading? An omitted item is not a saving. Add the cost of completing it before ranking the offers.

The core affects performance but does not determine the price alone. Thickness, facings, format, colour and order size also count. There is no fixed price ranking for every PIR, mineral wool and EPS panel: configuration and purchasing terms can change it.

Confirm thermal, fire and acoustic performance for the complete solution. Equal core thickness need not deliver the same result. Agree the required performance before comparing prices. For a substitute, consider its effects on details, weight and installation logistics.

Mark quantities as provisional or confirmed. Distinguish an estimate from a cutting schedule approved for order. Identify fixed sums and costs that vary with area or labour hours. You can then update one part of the building without recalculating everything.

Finally align the tax basis and scope. For a comparison including VAT, state the assumption and apply it to the appropriate items. Keep the final quotation and exclusions so the recipient can compare the delivery with what was actually priced.

For phased orders, allocate quantities and freight to each delivery. This distinguishes a change in material rate from an increase in handling costs.