With the Victoria and Albert Museum, the Tate Modern, and now the British Museum all touting expansion plans, it seems the global economic downturn hasn't taken the London art world with it.

The British Museum announced this week an ambitious £135 million ($198 million) extension intended to accommodate blockbuster exhibitions. Designed by Richard Rogers's firm, Rogers Stirk Harbour and Partners, the space incorporates five linked pavilions with glass and stone facades and seven levels, three of which are underground for storage. In addition to storage and exhibition space, the new buildings will also house conservation and science laboratories.

Some £90 million has already been raised, with part of the funding coming from the U.K.'s Department of Culture, Media, and Sport.

The extension is set to open in late 2012, pending approval of the design.