Among the nominations battling it out for the £100,000 prize are John McAslan's refurbishment of the De La Warr Pavillion, which was reopened last year, and Softroom's design for the V&A's Jameel Gallery of Islamic Art.
Last year's winner was Brunel's SS Great Britain, which was praised as being 'visual poetry' by the judges.
This year's long list also includes work by BDP for its Kelvingrove Art Gallery, which was also nominated for the Doolan prize in 2006, and Purcell Miller Tritton's treatment of King George III's country retreat at Kew Gardens.
Chairman of the judges, broadcaster Francine Stock, said: 'This year's longlist shows great variety and contrast - from a textile study collection to a substantial metropolitan museum, from a dedicated library and a spectacular national museum exhibition to a stylish and enterprising arts centre.
'We were hugely impressed by the way these entries seek to encourage audiences.'
To see the full long list visit www.thegulbenkianprize.org.uk