experienced their worst election result since 1950. exit polls suggest the csu, mrs merkel‘s bavarian sister party, has lost its absolute majority. the greens and the far right alternative for deutschland made the biggest gains. now on bbc news david sillito reports on the shortlisted buildings — including the winner — for this year's riba stirling prize, one of the most prestigious awards in architecture. how much? i think it was over $1.5 billion, maybe $1.75 billion by the time we got done. you don't realise the scale of how big this build is. previously, most of us spent most of our time

studying in our bedrooms, which can be a bit dark, boring and also quite lonely. i want to play, actually, in this space. great! but i think it makes everyone want to play! student housing is often very mean, and one of the meanest bits is the window. when you were told it was going to be made of compacted soil, what were your feelings? it's interesting. i had a sort of spiritual tingle. welcome to the roundhouse in london and this, the award ceremony

for the royal institute of british architects' stirling prize — the award for britain's best new building. now, when we think about architecture, we always think about bricks and mortar. however, it's more than that. it's solving human problems. for instance, what is the perfect colour to help a three—year—old get off to sleep? or how about this? how do you have a building that's good for chamber music but is also good for children's parties? or marrying the needs of high finance with having a roman temple in the basement? here's another question — what about including people in a funeral if they're not allowed to be anywhere near a coffin? well, all these problems have been solved by the architects who have been nominated for this year's stirling prize and, over the next half an hour or so, you are going to see how they've done it. and at the end, the announcement of this year's stirling prize winner. watch, enjoy.

so, if you are going to put your finger on one thing that makes a place a place, what is it? we're in cambridge. this is storey‘s field. it's a sort of village hall built by cambridge university. the university had this specific problem that it's very, very expensive to live in cambridge, housing was crazy, they need to attract the best researchers from around the world, but researchers with young families could not afford to come and live in cambridge. instead, they were going to harvard, they were going elsewhere. so they built this new development with this community hall as its centrepiece. my guide was daisy froud, who's an architectural consultant — an expert at helping communities get

the buildings they need. and this is a place she loves. so we enter the reception of the building. it is quite a nice reception for a community hall. yeah, it does not — the whole building does not feel like a community centre, does it, in any way? so there are three of these multi—purpose rooms. so this is a multi—purpose room? yep. so these rooms can be booked and hired for all kinds of things. this is the medium—sized room. pretty big medium—sized room, isn't it, for a little community? the whole thing is so generous. and the heart of it is this — the nursery. and this is the shared outside space for all the children from the start to the finish of nursery, which is quite unusual. and to test it, we drafted in teddy and her sister allegra. i like that bit and that

bit and the roof. i think it would be fair to say it was a hit. the architects have travelled around europe looking at the best nurseries. everything has been thought through, even down to the colour of the nap room. this is the sleeping room for the nursery, so where the children come to take their naps. so this lilac colour, a whole piece of research was done — so, apparently, van gogh was a tremendous insomniac and he became quite obsessed about what is a colour that supports sleep? and he identified this perfect bluey lilac — that art historians have managed to work out what the colour was — that apparently, in the way it relates to uv light, best supports a sleeping environment. oh, that's crazy!

this is the perfect colour for sleeping? yeah! the essence of the challenge is its variety of functions. what is this? a village hall? this is the main hall in the community centre. so,it is a village hall, for a village that's just being built, then, isn't it? it's the equivalent of a village hall, but it's a village hall that's become a performance venue, but it's also a place for marriages, or memorial services. there are kids' classes that come on in here. but if you are doing dance, then chamber music, then rock, it helps if you can change the sound of the hall, which they can do. with the touch of a button, the blinds come down, the echo can change completely. the blinds are down.

give me a clap. he claps. quite an echo there. two seconds? the blinds are up halfway now so another clap, please. that sounded much deader. more of about a second. a second, a second. so blinds down, curtain across, another clap, please. it's really changed the sound, hasn't it? i think we are below half a second now. one, two, three, four, five, six, seven, eight. i think it's beautiful. very spacious and one of the most spacious community halls i've seen. very brand new and really nice. tate came to st ives because of this amazing legacy here —

an artists' colony that started in the early 19th century and continues to this day. we got to the point where he had four times as many visitors as we expected, so the gallery was bursting at the seams. the community wanted the gallery to expand, but at the same time they wanted it to be integrated into the landscape. we did this by excavating into the cliffside so that we could create the largest possible gallery — level with the existing galleries. st ives sits as a spit of sand out into the atlantic, which captures both the east and the west light. and it was this particular double light that attracted artists here in the first place. the roof of the gallery is made up of massive concrete beams, above which are six very large light chambers that capture this very particular light of st ives. you could say that daylight was the primary material around which the gallery was built.

inside the gallery, it was incredibly important that we provide art handling and staff spaces and this created a small building that sat above this landscape, and, as it was looking out to the sea and up at the sky, we chose to clad the building in a glazed tile, which reflects the sea and sky and captures these two primal elements of the cornish landscape. you don't realise the scale of how big this build is and how clever it was to imagine that it would fit here until you actually come into the finished space and you see it for the first time and it was just amazing. i am just thrilled. to me, this is a testament to true dialogue with the communities of cornwall, resulting in incredible architecture. we identified the need as a campus university to provide as much

residential accommodation for students as possible. the client really wanted as many rooms as they could get on what was a very controversial site. historic landscape, listed buildings — and to do that in the least controversial way. the project consists of 210 bedrooms in three buildings in the grounds of grade ii—listed house. the building is a marriage of two histories — the brickwork from the georgian house and the concrete frame from the 20th century estate. what i really like about the development we have done here is the way it sits with the surrounding buildings. they look like they have been here forever. one of the features that really struck us was the bay window, and that became the inspiration

for a whole series of elements within the scheme. student housing is often very mean, and one of the meanest bits is the window. but in this context, in a garden, we thought why not some french windows? generous, kind, and it gives them access to a balcony, wonderful daylight, but actually outside space. it is very important students don't feel isolated. it's very easy for them just to live in their room. we have focused on making sure the communal spaces are bigger than you might expect. we have also created, used, if you like, the grounds to develop outdoor space where people can meet, and it means they are encouraged to socialise. it's very different from your typical student hall sort of accommodation. you see the greenery, you see the people. it just adds something different so you know it is roehampton, but it doesn't feel like roehampton — it feels like home. what the client was looking

to achieve was a space for lectures and performances where the whole community of the college could come together in one space. and in addition, what they wanted to do was to engage with the broader community of university and the city of oxford, and it could extend the intellectual life of the college. we host the oxford literary festival, where people come from all over the country to hear great writers and speakers. it has this beautiful auditorium in the style of an ancient greek amphitheatre. community spaces available for dance, exercise, play rehearsals, break—out space, so it's a building all about reaching out and coming together. i think the thing that i hope makes the building special and unique

is the idea of a theatre in a beautiful garden setting. many lecture theatres are quite closed in, they're quite contained and they're permanently blacked out and we tried to design it so that light comes in from different angles. so as you're standing in the lecture theatre, the clerestory windows are giving you light from the sky, you can see beyond out into the illuminated cricket pitch, but also into other shady parts of the garden which are full of dappled light coming through the trees. previously, most of us spent most of our time studying in our bedrooms, which can be a bit dark and boring and also quite lonely. where this, in comparison, now we can study in the nazrin shah centre which is much brighter an area and it also means we have a social space whilst studying as well. it's a really nice balance to have. because the sultan nazrin shah centre is in our beautiful historic landscape, sustainability credentials were really important to us. but also, resilience against climate change. we're on the flood plain here, but the building is raised up above the flood plain,

so we're pretty confident it's going to be here for 300 years, just as the college has been in the past. is this the main entrance? this is the main entrance. it's a bit hidden, isn't it? yes, he doesn't like to show up, he wanted to respect the buildings around us. this is our main reception and we are walking into the vortex. this is the vortex? the vortex. yes, it really is called the vortex. this is a building designed to slowly reveal itself. this is our pre—function space with the tapestry and art that is all around the area. that is james bond, isn't it? after all of that, it is just the lifts. so, where is the office?

it's upstairs, so this... we cannotjust walk in there? no. we have to go up to the top? we have to go to the pantry. there is nothing holding this lift up. exactly, so these are special lifts. it is not a pulling force but a fork force. so you're pushed from below... exactly, so there is no cabling — that's why it's glass everywhere. on the sixth floor, the big reveal. this is where everyone starts their day. and these are the petals, aren't they? this incredible ceiling. those petals are new technology. they throw out light and absorb heat and sound. at the heart of the building is this central space. it is where you pick up coffee, meet and chat before heading down the winding central ramp to your desk.