Temperature sensitive, doors, wall and floor will swell when the sun hits the shed directly and will return once the temperature of the plastic decreases it returns back to normal. At least in my case. 
Over all its is a nice shed and I recommend it. This is my second one, first one lasted about 12 years, about 8 years of having the first one, the edges started cracking and the top grey plastic caps cracked. Lifetime warranty sent me the replacement pieces.