All of the timber framing and cladding will be supplied pressure treated. This is a lifetime preservative treatment. The preservative is forced into the timber under pressure and penetrates below the surface, whereas all other treatments apply a coat of stain to the surface of the timber only. Pressure treatment is almost colourless except for a slight green tint caused by the copper content in the preservative. No further treatment is ever needed but if you want any particular colour you can paint over pressure treated timber with normal wood preservative.