A retrofit can reduce energy use and retain parts of the existing building if their condition is assessed first. PIR is useful where space is tight and good thermal performance is needed. The environmental outcome also depends on service life, waste and how the building is used. Sound structural elements, a dry substrate and watertight sections of roof have a value beyond the purchase price of new boards. Keeping serviceable components can reduce demolition and transport. Decide which layers to retain on more than waste savings alone.

A well-designed pig house keeps conditions suitable for the animals, can be washed efficiently and is straightforward to operate. Insulated walls and roofs reduce the influence of outdoor weather. PIR boards can form part of the envelope, but their selection depends on the ventilation system, the durability of exposed surfaces and how each area is used. Temperature requirements vary with the age, weight and production stage of the pigs. Begin with the layout, stocking levels and husbandry system. Use these to design the envelope and services, including separate controls for areas with different needs.

The withdrawal of a sprout suppressant formerly used in potato stores changed storage practices. Residues in older buildings need separate assessment even after treatment has stopped. Temperature, moisture and crop condition also matter. PIR boards help stabilise the thermal envelope but cannot replace hygiene, ventilation or appropriate storage practices. Do not assume that a substance used for years is still permitted: check current authorisations and conditions of use before choosing a treatment. The building should support the storage method. Thicker insulation alone cannot take its place.

A livestock building, food store or workshop needs a roof that keeps rain out and limits heat transfer. The underside may also have to withstand moisture and regular cleaning. A PIR roof panel can meet these needs if its facings and joints suit the operating conditions. Thickness alone is not enough to make the choice. The inner surface, supports and use of the building matter just as much. Above livestock, the roof is exposed to humid air, dust and gases from the animals. In a food store the surface must be easy to keep clean. In a workshop, processes may produce extra heat and sometimes fumes.