We bought a standard coop with an upper portion that closes and has the nesting boxes and a lower open small coop portion. We've decide since we can't leave them to free range during the day while we're at work all day, we wanted to build a big run (chicken playpen or play yard as my husband refers to it) off the coop. My question is two fold - does anyone recommend adding a roof that's water proof? And second, should I extra waterproof the pre built coop? I'm worried (probably unnecessarily so) about them getting wet and cold.... Especially in the winter.