Most popular wall thicknesses for garden buildings are 28mm, 40mm, 44mm, 58mm and 70 to 92mm. You can find 19mm walls on the market, but these are mostly very small tool sheds or very poor garden houses with a very short life span. We would not recommend you to go for less than 28 mm wall thickness. 28 mm walls are usually single tongue and groove logs and suitable for storage sheds and smaller garden houses up to 8-9 m2. If you are after a smaller garden building with a very affordable price, these garden rooms and storage sheds with 28mm wall thickness are a smart choice. 44-58mm wall logs have double tongue & groove and with these walls you can easily go for 20 m2 garden buildings and even larger. Compared to the 28mm walls they are not only sturdier but also provide better insulation and a really solid feel. As a conclusion, 28mm walls are more than enough for storage sheds and 4-9 m2 garden summer houses, but if you are looking for a larger building with better insulation make sure you choose walls 44mm or thicker.