How do you estimate the cost of a sandwich panel house before ordering the cladding?

Record the usable floor area, number of storeys and shape of the building. Add the heating, ventilation and finish requirements. A simple plan makes comparison easier, but the house still needs to be designed. Window reveals, plinths and roof junctions each have a cost that cannot be derived from total facade area alone.

Panels are priced by the area of the elements ordered. A house with a 90 m² floor plan can have a very different total panel area. Wall quantities depend on perimeter, height and openings. Roof quantities depend on slope, overhangs and the shape of each roof plane. Measure the walls and roof separately.

Deducting the area of every opening can underestimate the order. The cutting layout determines whether the offcuts can be reused elsewhere. Distinguish the area covered from the total panel area to purchase. A numbered layout showing the length of each panel provides a practical basis for the take-off.

For this exercise, assume 90 m² of wall panels and 110 m² of roof panels. The illustrative rates including VAT are approximately €41.66/m² and €50.92/m² respectively. The table converts the original line totals into euros before rounding. These figures show how an estimate works and which costs arise beyond delivery. They are illustrative figures, with no market quotation implied.

Other parts of the house still need to be priced. For a project estimate, replace the example quantities and rates with design quantities and comparable quotations.

Include site preparation, foundations, the load-bearing structure and protective treatments for its components. Allow separately for windows, doors, floors, partitions and finishes. Steel panel facings alone do not determine the interior layout or provide fixing points for every heavy fitting.

Price the services, utility connections, design work and site supervision required. Comfort, acoustics or fire protection may call for an internal service zone or lining. Include it from the outset if it is part of the design. Adding it later distorts the comparison between construction methods.

Long panels need a delivery route, unloading space and suitable lifting equipment. A narrow entrance or a small gap between buildings can change the installation method. Check who supplies the equipment and operator, prepares the storage area, protects the panels and takes the final production measurements.

Coordinate foundation and frame construction with the panel order. Changing the dimensions of a finished panel may create waste or require a revised junction detail. Base the contingency on identified risks such as ground conditions or the extent of utility connections. The appropriate allowance varies from one site to another.

Check that the alternatives provide equivalent thermal, fire, acoustic and functional performance. Thinner cladding or an omitted finish may reduce the initial price and change the result. Record the work each contractor undertakes to deliver, the supporting documentation and the acceptance criteria.

Use a whole-house energy calculation to assess running costs. A change in panel thickness cannot be translated directly into a percentage saving on bills. Ventilation, windows, doors, equipment and occupants also influence consumption. Include both the cost to finish the house and the running-cost implications of the chosen standard.