From the back room of his house on the South Side Slopes, Ronald Hays can watch the heavens open and shower rain or snow upon the city. But it's the view in his guest bedroom that is truly heavenly: Mary, Joseph and the baby Jesus at the center of a bustling Bethlehem, watched over by a host of hovering angels 300 strong.

Mr. Hays' Nativity scene, which he leaves up year-round, incorporates more than 800 figures and fills one side of a small bedroom. Scattered throughout the rest of his small house are four artificial Christmas trees, which have been fully decorated since November 2006.

"Christmas is my special holiday," he explained. "I left them up last year then just ran out of time. By June or July, there was no use taking them down."

It was the first time for the trees, but the manger has been a permanent part of Mr. Hays' home since he started it four years ago. It began with a few pieces picked up at after-Christmas sales, then steadily grew. He hand-paints some figures in the same somber palette as the rest and builds most of his own scenery from repurposed packaging and dollar-store items.

Mr. Hays, 70, pointed to a rug merchant's stall in the Bethlehem marketplace. He used a scrap from an old pair of pajamas to make the striped awning and fabric from some curtains to fashion a tiny Oriental rug. A former steelworker and state liquor store employee, he used Roman arches from a Sambuca replica of the Coliseum and placed within them windows made from dollar-store picture frames.

"It's not only what I see, it's how I see it," he said. "Other people see picture frames. I see windows."

He brought that same vision to this 1920s millworker's house, which he said was a rundown shack when he bought it in 1960. He grew up in a house across the street and helped raise his six brothers and sisters there after his mother died.

Mr. Hays has given every inch of the house and garden an ornate Italian sensibility. The closed-in back porch where he watches storms has a fireplace with a huge white mantel that he built from stock molding, then detailed with black and gold paint. Recently, he attached blue pleated silk to his dining room ceiling -- with 3,000 staples.

Thirty years ago, he began to collect religious art, which now covers nearly every vertical and horizontal surface. He has nearly 400 Madonnas, 85 icons and dozens of religious paintings and prints, ranging in style from Renaissance to Surrealism (Dali).

Siting in his back room, Mr. Hays is at eye level with the green copper cupola of St. Josaphat Roman Catholic Church, which he sometimes attends. He also goes to St. Matthew and St. Peter, all now part of Prince of Peace parish.

Mr. Hays enjoys sharing his house and its decorations with friends at six parties during the holidays. Two of his sisters -- DeeDee O'Hara of Mount Oliver and Lorraine Hays of the South Side -- make the food.

Since he can fit only about 30 people inside, the guest lists are slightly different for each party, with new faces every year. Visitors can't help but gape at his collections and at the Nativity scene, his greatest and still unfinished work.

"When I started it, I never thought about moving it," he said. "I don't think it's going to ever come out."