This Information Paper reviews the modified wood product, ThermoWood®, focussing on its use as exterior cladding and giving the results of long-term field trials. It examines the properties of this aesthetically pleasing material and its environmental impacts, coating performance, service life prediction and specification for exterior cladding. The Information Paper will help building owners, architects and designers to decide on the suitability of ThermoWood® for new domestic and commercial construction and refurbishment projects. It will also be of interest to all those involved in specifying ThermoWood® materials.