The time has come again for RIBA's 2015 Stirling Prize, the institute's highest accolade for "best new building" in the United Kingdom. Starting out with the regional London Awards followed by the National Awards earlier this year, RIBA announced today the six buildings that are still in the running for the coveted Stirling Prize.

As usual, the shortlisted projects are a fairly striking bunch typically designed by British architecture firms that have graced RIBA nomination lists time and time again, or have already won RIBA awards. (Out of the shortlisted firms this year, MUMA and Reiach and Hall Architects are first-time Stirling nominees.) On the other hand, high-level awards like the Stirling Prize that evaluate new buildings for "design excellence and significance in the evolution of architecture and the built environment" spark debates regarding what should be valued in architecture and the open-ended question of "What is good architecture?"

Check out the shortlist below, along with some jury comments:

↓ NEO Bankside by Rogers Stirk Harbour + Partners (also pictured in the cover photo)

A set of luxury housing towers featuring exo-skeleton and external lifts. The Prize jury commented on the project as a "tour de force in its achievement of density, its use of economical pre-fabricated elements, and its intricate weaving of public and private space...The articulation of the buildings, the expressed diagrid structure (argued for by the engineers, it was to have been hidden), the quality of the glazing systems and the external lifts make the scale feel almost cute."

↓ Burntwood School, Wandsworth by Allford Hall Monaghan Morris

"The architectural expression throughout is bold, characterful and adds to a sense of this being more like a university than a school...A modular pre-cast concrete cladding, using eight different molds, with canted edges and different sized glazing panels is playfully arranged on a rigid grid creating surprising interior spaces. The rooms are gracious and full of light, and there are many double, even triple-height spaces. Internal corridors all end in well-framed views."

↓ Darbishire Place, Peabody social housing by Niall McLaughlin Architects

"The dignified new building, with its refined proportions and details, replaces a well detailed and proportioned Peabody mansion block taken out in World War II by a V2 bomb, along with another block whose footprint now provides a garden at the heart of the newly completed courtyard still graced by the remaining three Edwardian blocks. A casual comparison of the old and new elevations reveals the subtlety of the new architecture...[T]he new building complements its neighbors without mimicking them."

↓ The Whitworth, University of Manchester by MUMA

"A project for all seasons, where art, nature and architecture combine - this could be the eulogy for a building which is neither high-key nor overtly fashionable, rather it is reminiscent of 1950s Aalto...The scheme revises the basis of the environmental standards for exhibiting art with old and new galleries flexible enough to be black-box or allow daylight in. The environmental strategy is equally inventive taking a passive-first approach that has been delivered unobtrusively, with no exposed services whatsoever – a curator’s delight."

↓ Maggie’s cancer care center in Lanarkshire by Reiach and Hall Architects

"So the architects were ideal candidates to solve the problem: how to make something that is of the world and yet gives shelter from it, that turns its back but does not close its eyes. The answer is in a new surrounding perforate wall of hand-made Danish brick that recaptures some sense of paradise – which means literally walled enclosure – offering a degree of separation from the nearby hospital grounds. Stand on the rear terrace and you can see the houses opposite, walk down the steps into the courtyard and they and the rest of the worlds are hidden..."

↓ University of Greenwich Stockwell Street Building by Heneghan Peng Architects

"Located in the UNESCO World Heritage Site at Maritime Greenwich and opposite Hawksmoor’s St Alfege, this building...is a startling building to put in Greenwich. Conceptually strong in urban design terms, it relates well to the street in materiality and massing...Externally the forms are well articulated giving depth and interest, with fenestration carefully considered to take advantage of key views, vistas and reflections, particularly on the long side elevation facing the railway. The building is full of light and generous spaces and benefits from clear vertical circulation."

RIBA will reveal the winner in London on the evening of October 15.

Last year, Haworth Tompkins' Everyman Theatre scooped up the prize. Other previous winners include the Astley Castle by Witherford Watson Mann Architects and the Evelyn Grace Academy and the MAXXI Museum — both by Zaha Hadid Architects, which won two years in a row.