Ever since Pearl Properties quietly scooped up the doomed Boyd Theatre on Chestnut Street in October, Philadelphia has been left to guess its intentions. Would Pearl install a modern movie house behind the facade, as the city was promised during a financial-hardship hearing at the Historical Commission? Would the company replace the theater with a retro, 1920s-style apartment tower? Even as backhoes were gnawing all spring at the historic art deco auditorium, Pearl remained mum.

Now, in preparation for a design review Tuesday at the Historical Commission, Pearl has finally revealed its hand.

A filing made public Wednesday shows that Pearl plans to replace the Boyd's exuberant, art deco auditorium - a triumph of Hollywood's golden age - with a generic, 341-foot-tall apartment tower wrapped in red, white, and gray metal panels. In addition, a bland, three-story commercial building will be wedged between the Boyd's old marquee facade and the limestone building that occupies the corner of 19th and Chestnut.

It would be an understatement to say that Pearl's design is no gem. A charmless, bulky stack of rentable units, it does no justice to the memory of the Boyd or, for that matter, to the lively commercial architecture that lines this stretch of Chestnut Street.

Pearl's 27-story tower, which will back onto Sansom Street, is a plain rectangular slab that has been broken up by baylike setbacks at the corners, and what look like scrims and inset windows on the east-facing facade. Based on drawings prepared by Eimer Architecture, it appears that structure will be wrapped up with metal panels, now the default on developer-built apartment buildings. That isn't architecture; it's a colorful form of weatherproofing.

You can see mediocre metal boxes just like this going up all over Philadelphia. Actually, they're appearing in cities across America. Built by big development companies with a sharp eye on the bottom line, the designs can be seen as a physical manifestation of the business plan. The buildings are designed to be assembled quickly, using stock parts, much like an Ikea cabinet. All the architect does is pick the colors and work out the pattern.

While such rote facades are sadly becoming the norm, this is an instance where Philadelphia had an obligation to demand better. The Boyd was legally protected under the city's preservation law until the Historical Commission granted its former owner, Live Nation, financial hardship and permission to demolish everything behind the Chestnut Street facade. At the time, the commission was told that a multiplex would be constructed in the Boyd's place. The moment the demolition was approved, the property was flipped to Pearl.

Because Pearl already owned several properties east of the Boyd, it was able to combine them into one large parcel, allowing it to build the tower "by right," that is, without zoning board review. As a result, it hasn't even presented the project to the local civic group, the Center City Residents Association, its president, Jeff Braff, confirmed.

In its assessment of the design, the commission staff has flagged a few minor issues. Staff members object to Pearl's plan to close up the Boyd's open-air vestibule, where movie tickets were sold. They also want Pearl to replicate the colored windows over the marquee, rather than replace them with clear glass.

This is really nitpicking. The flat, lifeless structure shown in the rendering isn't worthy of the richly detailed, historic facades that will bookend it.

How Eimer won this project is a mystery. (Eimer and Pearl did not return phone calls.) There is nothing on its website to suggest the firm has ever designed a tower - or an actual building. Its specialty seems to be restaurant interiors. The Historical Commission has the power to demand that Pearl come up with a better design. So does the Civic Design Review board, which would vet the design before construction starts.

The Boyd, like all movie theaters, was conceived as a commercial undertaking when it was designed in 1928 by Hoffman & Henon. But making money wasn't the only motive of the design. It shouldn't be this time, either. Too much has already been lost.