How do you choose sandwich panels for a home occupied all year round?

A PIR insulation board with thin facings such as aluminium foil is a different product. It needs a suitable substrate and other layers to complete the wall or roof. Two products with the same core material may serve quite different functions. Identify the required product type for each part of the house at the concept stage.

Determine the required U-value for the particular wall or roof and its service conditions. Check the panel thickness, core type and the data for that application. Detail the junctions at foundations, corners, windows and roof slopes separately. A well-insulated panel cannot compensate for a thermal bridge at a poorly detailed junction.

For year-round occupancy, also check airtightness and internal surface temperatures. Detail service penetrations before ordering the panels. If openings are decided on site, it is harder to maintain continuity of the layers. Detailed drawings provide a basis for inspecting the completed work, including features hidden behind the facade.

A bedroom beside a busy road has different acoustic needs from a store room. Assess the complete wall, its windows, air inlets and junctions that may transmit sound. A laboratory figure for a panel alone does not give the sound insulation of the whole facade. Set the target using the actual noise exposure before selecting the cladding.

For a lightweight roof, consider rain noise and vibration transmission too. A suitable internal build-up may help, but its performance needs to be established for the proposed structure. Detail any additional ceiling so it maintains airtightness and avoids cavities in which moisture can accumulate.

Cables, pipes and ventilation ducts take up space. An internal service zone can reduce penetrations through the envelope and make repairs easier. Size it for the services to be installed, including the ducts, rather than assuming they will fit into any available gap.

Wall cabinets, washbasins and heavy equipment need suitable fixing points. A thin metal facing has limited capacity for attached loads. Position reinforcement and secondary supports to suit the interior layout. Keep a record of their locations so future installers know where they can fix replacement fittings.

Reaction to fire describes a product, while fire resistance is assessed for a complete assembly. Establish the requirements for the house design and check the classification of the actual wall or roof build-up. Thickness, supports, fasteners, the direction of fire exposure and the interior finish may all affect the classification.

A wall classification cannot be applied directly to a roof, and a result for one panel does not cover every panel with the same core material. If a particular internal lining is specified, omitting it changes the build-up. Account for service penetrations and junctions with adjoining elements, and agree the room finish with these details in mind.

Solar gain through glazing, shading and ventilation all affect summer comfort. Increasing panel thickness cannot replace shading at a large window or an effective air supply and extract system. The colour of metal facings influences how hot they become. Take this into account when choosing lengths and fixings, and coordinate the facade finish with the structural design.

Before building, check how services will be maintained and how an individual panel could be repaired. Allow for equipment you expect to add so future work does not involve unplanned cuts in the envelope. Accessible connections and clear drawings make it easier to adapt the home as occupants’ needs change while preserving the performance of its walls and roof.