A couple of news items guaranteed to register on Prince Charles' carbuncle-ometer: plans for London commissions by two of modern architecture's most innovative practitioners took a step forward this week.

Back in January Frank Gehry was announced as the designer of this year's Serpentine Pavilion, the temporary build that goes up during the summer and autumn in Kensington Gardens. The structure has now been unveiled. An "urban street" that provides a covered walkway from the park to the Serpentine Gallery, the design is typical Gehry, all glass and timber and improbable yet inspirational angles. The Pritzker Prize-winning architect's reputation for startlingly attractive buildings that don't always work so well in reality may be suited for the temporary nature of the Pavilion, but depending on the public reaction it could be a precursor to a permanent Gehry on the London skyline.

Rem Koolhaas, himself a former Serpentine Pavilion designer, is set to make a more lasting mark. His Office for Metropolitan Architecture has won the competition to redevelop the Commonwealth Institute in Holland Park, a project we first mentioned last year. OMA's proposal will involve repurposing the building's 'concrete tent' structure as a gallery or display area, while the surrounding area will be redesigned with a new residential element. Various intriguing ideas have been suggested for the site's entrance, including a "Russian Constructivist sculpture-style structure" on the High Street Kensington side, and it seems likely that the Institute will once again become one of west London's key attractions.

Whether our future King agrees is another matter entirely.

Image of Rem Koolhaas and Cecil Balmond's 2006 Serpentine Pavilion from Billa's Flickrstream