This is a guide to the efficiency of the building walls and ceiling make up in terms of u value. The lower the number the better the insulation (u value).
PIR (polyisocyanurate) boards – Polyisocyanurate (PIR) is one of the most efficient insulation material used in construction. This product is an improvement of previously used PUR boards (polyurethane), typically produced as a foam and used as rigid thermal insulation. This type of insulation offer many advantages when compared with other traditional insulating materials and over its useful life will save 80 times more energy than was used to make it. Most popular type of PIR insulation board comprises a rigid PIR insulation core sandwiched between two high performance aluminium foil facings to create a tough, durable, light weight insulation board that performs whilst reducing the overall cost to build.
| Construction | U Value |
| 19mm shiplap, no insulation (shed/workshops etc): | 3.07 w/m² K |
| 50mm thick solid log cabin: | 1.77 w/m² K |
| 70mm thick solid log cabin: | 1.39 w/m² K |
| 19mm shiplap and 50mm thick fibreglass and plaster board: | 0.60 w/m² K |
| Cedral cladding and 40mm cavity and 6mm ply sheathing and 50mm fibreglass and plasterboard: | 0.57 w/m² K |
| 19mm shiplap and 70mm PIR (polyisocyanurate): | 0.26 w/m² K |
| Cedral cladding and 40mm cavity and 6mm ply board and 70mm PIR (polyisocyanurate) and plaster board: | 0.25 w/m² K |
| 19mm shiplap and 70mm PIR (polyisocyanurate) and 19mm tongue and groove, v-joint internal cladding: | 0.25 w/m² K |
| Quinneys Gold Option (price on application) Cedral cladding and 40mm cavity and PIR polyisocyanurate) and 25mm PIR over stud work and plasterboard: | 0.19 w/m² K |
Note: 70mm PIR board can only be used with CLS ex 100mmx50mm stud work walls. We can use 50mm PIR board with 70mm stud work walls. All the above u values are for guidance only.