A radiation curable and at least partially biobased urethane (meth)acrylate for use in a one-component coating composition for cladding an outdoor surface of a building, obtained from the reaction of at least the following compounds: a. A polyisocyanate compound having a biobased carbon content of at least 20%, preferably at least 50%, as determined by method A of the standard ASTM D6866-12: 2008, and b. A (meth)acrylate compound, different from compound a, and containing a reactive group capable to react with isocyanate groups.