News Treehugger Voices What's All This Architect Love for COR-TEN Steel? By Lloyd Alter Lloyd Alter Facebook Twitter Design Editor University of Toronto Lloyd Alter is Design Editor for Treehugger and teaches Sustainable Design at Ryerson University in Toronto. Learn about our editorial process Updated February 11, 2021 Share Twitter Pinterest Email ©. Luis Salazar via designboom News Environment Business & Policy Science Animals Home & Design Current Events Treehugger Voices News Archive Designboom shows a cute modular house that the architects, James & Mau, call a "living box." It has natural ventilation, passive solar design and "an intelligent façade." It's called "Casa Menta" or mint house, because of the mint plants shown on the perforated exterior COR-TEN steel skin, which once again raises a question. © Luis Salazar via designboom I continue to be puzzled by this current fascination with COR-TEN steel. Neil Young must have been thinking of it when he wrote that rust never sleeps. Its manufacturer continues to tell designers that they shouldn't use it for architectural purposes: Special attention must be paid to the drainage of storm water to prevent staining of surrounding structures, sidewalks and other surfaces....The tight oxide skin of COR-TEN® Steel reforms after abrasion from snow, ice, sand, dirt and hail.... As the skin reforms, the product actually becomes thinner and eventually will be perforated. © Guillermo Hevia H. via archdaily And indeed, many of the projects we have shown that are made of the stuff show the trademark rivers of rust, as seen here in this lovely office building in Chile. Lloyd Alter/CC BY 2.0 The Barclays Center in Brooklyn is one of the biggest installations of COR-TEN around, and I saw a bit of staining when I visited it a year ago. According to the New York Times, quoted in the Atlantic Yards Report, The steel on the Barclays Center was weathered before it ever made it to Brooklyn. Gregg Pasquarelli, a principal at SHoP Architects, which designed the arena, said the steel components spent about four months at an Indianapolis plant where they were put through more than a dozen wet-and-dry cycles a day. ...The process put about six years of weathering onto the steel. © Norman Oder/ Atlantic Yards Report However, these photos taken by Norman Oder of the Atlantic Yards Report show that it is still quietly rusting away. © Norman Oder/ Atlantic Yards Report A tenet of green building is that it should last a long time. It seems to me that using a material that you can actually watch deteriorate before your very eyes is a mistake. © Sarah Wigglesworth Architects In some places it can be appropriate; I have always loved Sarah Wigglesworth's gutsy Cremorne Riverside Centre from 2008, designed to look like rusting upside down boats, and replacing some shipping containers. As one user said, " "We tell people we used to operate out of a couple of rusty boxes, but that now we have a new building, we operate out of a couple of rusty boxes."