We have a little tikes one, bought off eBay in great condition for £20. DD loves it! It is hollow plastic and slots together quite sturdy, has door and windows and roof, not easy to climb on, niece 7 and nephew 4 also love playing in it too. It stays out all seasons and though faded is no worse for wear.
Weather is glorious and 14mo DS has recently discovered the delights of running around the (now safely-weeded) garden. We've got space for a Wendy house; is there anything we should be looking for? Anything to avoid? We'd hate to get something and realise too late that DS can climb on the roof or get his fingers stuck somewhere ridiculous.