A former bullion store in south London may seem an unlikely place to meet on the last Sunday morning before Christmas. There are certainly 1,000 places one would prefer to be. Bed being top of the list.
The AJ is meeting with London's chapter of Architecture for Humanity and homeless charity Crisis to see how the groups take on the unenviable task of transforming what looks like a prison into a welcoming, temporary home for the homeless.
For the second year running the two charities have joined forces to help with the Crisis Open Christmas (OC) programme.
The project borrows disused buildings across London, transforming them into centres offering shelter to homeless people over the Christmas period, where they can access essential services, and use their temporary homes as launch pads to help them off the streets in the New Year.
The volunteers have their work cut out. The post-war building in Elephant and Castle is bleak. The décor is wroughtiron gates, metal staircases and cages. As a consequence, it can take the form of many institutions a homeless person might be familiar with - and would wish to avoid.
Mick Bateman, head of OC, is well aware of how a space can alter a person's well-being, and was a driving force behind Architecture for Humanity getting on board.
'The way homelessness is treated has come a long way in the last 35 years, ' he says.
'But OC became a bit stagnant three or four years ago, and we decided we needed a change. What we wanted to do was to create a fiwowfl factor, and that's where Architecture for Humanity came in.'
The week-long project takes place from December 23 to 30, providing homeless and vulnerably housed people with options ahead of the New Year.
The centres give homeless people access to services they would not normally have, such as a hairdresser, a dentist, medical and legal advice, and even IT lessons.
Megan Yates heads up the Architecture for Humanity side, and was key to getting the group involved with Crisis, helping to transform the smaller shelters last year.
'It's about putting the effort into the empty spaces, ' she says.
'We are taking buildings, which people don't want to use, and turning them into places that can be lived in.'
'You could spend a fortune, but that's not the point of OC.
We have a sustainable agenda, providing something that's affordable and renewable.
'It's an interesting brief, ' adds Yates. 'It's about creating a space which will help to give back some of their dignity, a space which will make the guests say, 'Wow, someone has made this effort for us.'
The process isn't easy. For starters, the architects are trying to come up with solutions to spaces they have not even seen, as the buildings were not secured until last week.
Crisis has four buildings this year, ranging from an office block - soon to be demolished to make way for Rogers' Leadenhall building in the City - to an old person's home in Kennington, south London.
The programme offers a massive challenge to the architects, but it is this challenge that brings them here.
Jen Cirne from PRP Architects said: 'I have volunteered with Crisis before and when Architecture for Humanity came in it was perfect for me.
'When you work on a project as an architect, it can normally take years to see it from start to finish, so it is really rewarding to work on something like this, which is finished in less than a month.
'It offers different challenges, ' she adds. 'Normally we have nothing to do with the building side of things, but we soon realised we had to build what we were designing.'
Crisis and Architecture for Humanity are now looking at how to take OC forward.
A regionalisation of Open Christmas in the capital is the next step, which will employ a new system allowing OC to be staged anywhere.
The aim is to start using public buildings which can be used year after year, rather than those about to be knocked down.
This would then allow the two groups to design the modules - the furniture used to kit out the buildings - which could be kept in a warehouse and used every year, making the project truly sustainable.
The former bullion store we are standing in is set to be redeveloped once this project is completed, but a more important transformation is already happening.
The walls are changing from an uninspiring 'office grey', to bright, vibrant colours using wallpaper designed by Jocelyn Warner, which was featured in Vogue last year. It's a strange juxtaposition.
'We want to make people aware that what we do is not bashing buildings about, it's how we try and transform a space with the tool kit we have designed, ' says Bateman.
'We want homeless people to use OC as a gateway. We don't want people to come back next year. That's the point, and that's our message really.
We don't want to see these people again, because it will mean they are off the streets - and we have done our job.'