But, oh, just step inside the place at 3617-19-21 Haverford Ave., which stretches all the way back to Mount Vernon Street, and hang onto your eyeballs.
Dupree has carved this 8,646-square-foot former garage into classrooms, studios and, tucked into funky spaces, three quirky apartments. There's a putting green in the hallway; a secret passageway behind a kitchen. And random doors lead to odd spaces bursting with the building's real treasure: more than 5,000 pieces of artwork created by Dupree.
Countless portraits and contemporary abstract paintings hang corner to corner in the main hallway, creating a gallery. Others lean against one another in a crowded loft.
Feather-adorned mini-cabinets with tiny doors dot a studio wall; Dupree was commissioned to create just one as a gift but couldn't stop.
Crazy-colored canvas landscapes of circles and squares (to be viewed through 3-D glasses) explode in the reception area, in hues bold and delicate, images solid and ephemeral, sizes tiny and massive.
"This is my life's work," says Dupree, 63, a native Philly artist, teacher and jazz lover who once likened his creative style to "throwing sound at canvas."
If his building were a piece of music, we'd hear Miles Davis, Dizzy Gillespie and John Coltrane playing for Billie Holiday and Ella Fitzgerald, backed up by Antonio Carlos Jobim.
If the Redevelopment Authority has its way, that song will be silenced when a wrecking ball makes room for something Mantua has needed for a long time - a supermarket.
Dupree agrees that neighbors deserve a decent place to buy groceries. But he's incensed that the the authority a) condemned and took his building, an up-to-code property whose taxes were fully paid, and b) offered him just $660,000 for the space.
"How am I going to re-create all of this for $660,000? It's impossible," he says. "I worked with a helper 10 hours a day, six days a week for seven years" to rehab the decrepit former garage he purchased in 2005 for $183,000. He says the roof alone cost $68,000 to replace.
Which is pennies compared to what it will cost to wrap and move his artwork, claims Dupree. He grew up rough in Southwark, tempered his anger in art and was only the 17th African-American to graduate from Penn's graduate school of fine arts.
If the authority wants his property, he says, they can have it - for $2.2 million. That's how much it was independently appraised for two years ago, when he saw development booming in Mantua, which abuts rapidly expanding Drexel University. (Brand-new townhomes sit a half block from Dupree's studios.)
"I can either stay here and enjoy the area as it improves, and sell to Drexel 10 or 15 years down the road," says Dupree. "Or the [the authority] can pay me now for what I could sell it for later. What I don't like is that [the authority] has taken that choice from me."
Spokesman Brian Abernathy says the authority is in discussions with Dupree.
"Every property that is condemned is part of a larger plan agreed upon by the Philadelphia Planning Commission and City Council," he says. "Our goal is always to come to an agreement."
For now, Dupree is appealing the authority's declaration of condemnation from a procedural and substantive standpoint, says his attorney, Christopher Booth Jr.
Procedurally, the authority condemned only two-thirds of Dupree's property. Which would be like the authority seizing the back of my house but not the front.
"Substantively," says Booth, "we're saying, 'Listen, there at least should have been an evidentiary hearing as to whether the authority took too much property in the condemnation.' Were there ways to assimilate Mr. Dupree's studios into whatever development is planned for the area? We know the neighborhood needs a supermarket, but this is still a man's property. You can't just seize the deed."
But seize the deed it did. Except that city records show the property is still in Dupree's name. He just got notice from the city for nonpayment of 2013 taxes - a year in which the authority has held the deed.
"Can you believe this?" he asks, mouth agape. "Again, the city wants it both ways. Well, it won't happen. I'll die fighting this."
On Twitter: @RonniePhilly