This is the model combined of roof and pool yard. Click here to see it http://plantsvszombies.wikia.com/wiki/User_blog:Big_plants_fan/PvZ_background_model_by_Big_plants_fan
To make this, download the pictures here http://www.mediafire.com/?aabcqfnduf4adqc
Then, print them out (the A4 size). REMEMBER: Print them out to the white paperboards.
And, When you done, please let me see your results! Any questions, please leave messages for me.