The thermal conductivity of the SBS polyurethane core is typically  0.025 W/m.ºK  Using the SBS  SIPs panel can provide extremely low U-values for walls. Depending on detail of construction this can be in the range 0.21 to 0.14 W/m².ºK.
For roofs designs can deliver U-values in the range 0.20 to 0.12 W/m².ºK.

SBS are happy to give advice on specific designs.