Advice on turning a Little Tykes playhouse into a chick coop please!

It will work fine.  Lots of folks have done this.  You can probably find examples in the coops section -- click "coops" in the brown bar at the top of the page.  Use hardware cloth (wire mesh) to cover windows, to protect from predators.  It's best to find a way to ventilate it at the highest point of the playhouse.  This lets humidity and ammonia escape.  You'lll probably have to cut a hole and cover with hardware cloth -- a bigger hole than you would think.  Even in winter there needs to be good air exchange at the vent, though it can be closed up tight everywhere else.  You may not need a solid cover for the window, depending where you live.  Chickens tolerate cold a lot better than heat.  The lower part of that door should make a good chicken door.

Here is an excellent article on ventilation

http://www.backyardchickens.com/a/chicken-coop-ventilation-go-out-there-and-cut-more-holes-in-your-coop

It should work just fine.  You need to build a run with cover or dog kernel will do.  I suggest build a roll out nest box so you can get the egg from outside or the back of the coop.

We have a Playhouse "Duplex"...... My husband built some bases to raise them off the ground for easier cleaning and to provide more shade for our chickens (we are in Arizona).  Then we put the roost all the way across inside both houses and they can go back and forth from side to side.  We used hardware cloth to cover the windows and latches on the doors.  It is working great and is easy to clean.  Here are a few pictures...... hope this helps get you started!

I'm planning on doing the same thing with one of these playhouses, Would you mind posting pics of how you set up the inside?  I'm in the california high desert.  :)

I don't currently have any interior pictures but I can tell you how we set it up...... we have a roost that goes completely through both playhouses.  It starts at the far left side of one/ through the two windows that are lined up together/ then all the way to the far right side of the second playhouse.  Our nest boxes are against the back wall..... one in one side and two in the other.  We move these from time to time to try different setups.  I like them on the back wall across from the door so I can quickly see if there are any eggs to grab!

Hope this helps..... let me know if you need any more info!

Thank you, that does help!  I was thinking of putting my nest boxes across from the door as well, but wasn't sure if the girls would like being right there as everything I've read says they need to be out of the main path.  I'll try that first and if they won't lay there I'll move it.  :)