Play structure designer Peter Rader with son, Luca, joins Ben Tzudiker on the deck that leads to the multilevel structure made from ordinary hardware store materials. (Ken Hively / LAT)
Don Grose included a working fireplace in the playhouse he sculpted, with help from his daughters Asana and Nyala, in their Long Beach yard. (Christine Cotter / LAT)
Asana Grose, 7, nestles into a niche of the dome-like design made of rebar, chicken wire, linen, papier-mâché and mortar. (Christine Cotter / LAT)
A crown, inset with glass circles made from plates bought at a discount store, tops the whimsical design. (Christine Cotter / LAT)
Colorful swirls of paint and layers of mosaics frame windows in Groses project, which took more than year for the middle school teacher to complete. (Christine Cotter / LAT)
The Groses tabby cat Nick blends in with the curves and the rainbow of mosaics. (Christine Cotter / LAT)
At the Hollywood Hills treehouse designed by Ray Cirino from recycled materials, Maud Dias, 8, slides down an aluminum pole that Cirino salvaged from trash. (Robert Gauthier / LAT)
Maud Dias hoists a basket of toys to the deck of the 12-foot-high structure, set into an ash tree. Cirino used recycled Douglas fir for the deck, and willow branches and curved metal strips for the railing. (Robert Gauthier / LAT)
Maud, left, and brother Hugo, 5, play in their aerie with its leafy backdrop. A buckle and gasket that support the tree will allow it to grow through the decking. Says Cirino of his creation, I wanted it to look like nature. (Robert Gauthier / LAT)
