"It's something that's easy. It's all around us," he said. "The homes here are really interesting, they're beautiful, and it's nice to record them. It's really as simple as that."
What started as a small personal project has grown over the years. He has more than 28,000 Instagram followers and has self-published two books with fellow Instagrammer Austin Hodges.
Hodges, 27, who studied photography at the University of the Arts and works at Metropolitan Bakery, started posting images a few years back. When he came across Cress' Instagram postings about a year ago, he noticed that they both had the same style, technique, and interests. On some occasions, Hodges said, they had even photographed the same home.
Each of their profiles features countless photos of the city's rowhouses, many of them with a brightly colored door: some orange, some purple, some blue. Others feature adjoining rowhouses juxtaposed, their colors playing off each other.
A few have ivy creeping up the doorway. There are doors of wood and doors of glass. Entrances that are traditional and perfectly rectangular, or tucked into private, arching alcoves. No two homes are alike.
Hodges and Cress became friends via Instagram and, eventually, translated their virtual friendship into real life and met in person. Though they've gone out to shoot together a few times, they mostly work alone, bound only by their mutual tag, #phillyhomeportrait.
This year, they sifted through hundreds of photos to create Homes of Philadelphia, a 60-page, 51/2- by 51/2-inch-square book - keeping in the style of Instagram - that features their photographs of the city's homes on simple, clean pages with white borders.
They self-published 10 copies and put them up for sale at Metropolitan Gallery 250, 250 S. 18th St., where their works were included in an exhibit on Instagrammers - and they sold them all. This summer they released Homes of Philadelphia, Vol. 2, and are now working on a third book that will feature older, rundown homes.
Hodges has acquired more than 17,000 Instagram followers and said he loves reading their comments, especially when people who visit his page say Hodges highlighted a home they passed before but never noticed.
"It's like creating a visual awareness of the city you live in," he said.
Hodges said he hopes #phillyhomeportrait inspires others to explore their neighborhoods, documenting the places they find beautiful.
"Just grab a camera and take pictures of it, because one day that may not ever be there again," he said.
To see the works of Billy Cress and Austin Hodges, follow them on Instagram at @billycress and @austinxc04.