As architects have expanded their practice beyond the built object and artists have moved out of the gallery, so the already blurred boundaries between the two disciplines, have become still more entwined within the realm of critical spatial practice. To engage with the terms of spatial agency, artistic practice must show some form of transformative potential. Although there are a large number of artists working with spatial relations, those included here influence the actual production of space or change spatial relations in some way.

Michael Rakowitz is a case in point, trained as an architect, his work straddles the divide between art and architecture. Based in New York, his most memorable project is paraSITE (1998), at once a critique and a making visible of the prevalent attitudes towards homelessness, whilst at the same time improving the material living conditions of those living on the streets. Rakowitz designed a series of inflatable shelters that plug into the vent outlets of buildings, creating a warm and dry space for their inhabitants. Custom designed for each individual their oddness in the street scape gives visibility to the homeless. In an interview, Rakowitz relates that the initial shelter was made from black plastic in the hope of providing privacy and darkness to sleep in, but upon consulting his clients, he realised that what was most important to them was to be able to see out in case of attack and a desire to be seen and acknowledged. The shelters not only comment on the situation of the homeless, but also the large amounts of energy wasted in buildings.

Marjetica Potrč's work also blurs the boundaries between art, architecture and urbanism working in diverse locations, from the informal settlements of Caracas, to the trailer parks of Florida, or in the West Bank. Trained as both an architect and an artist Potrč's work is situated in these locations but is also displayed in galleries. Moving away from the problem solving approach of architecture Potrč tries to learn from each context through observation, developing an understanding of the micro-processes involved in order to inform the eventual interventions. For example in the La Vega barrio of Caracas, Potrč worked with architect, Liyat Esakov, as part of the Caracas Case project to design a dry toilet that responded to the lack of water. Designed in consultation with residents, rather than providing a one-off solution, the toilet can be easily replicated. In another project based in Sharjah, United Arab Emirates, a small solar powered desalination device was installed in a school, in a context where solar energy is abundant but its use is virtually non-existent. As in the work of Rakowitz, Potrč's projects simultaneously reveal uneven living conditions whilst also working to alleviate them.

The artist, Thomas Hirschhorn's sculptural installations are participatory and collaborative in nature and fit within an artistic tradition including the Anarchitecture Group and Robert Smithson. Taking sculpture in its broadest sense as the manipulation of spatial conditions, Hirschhorn critiques architectural production through approximating and mimicking architectural structures. The project Bataille Monument (2002), named after the Surrealist writer, was located in a mainly Turkish neighbourhood of Kassel, Germany, as part of the Documenta art festival. The intervention included a television station, snack bar, an installation about Bataille and a library themed around his work. Inviting residents to participate in the installation through adding to it, the work raises questions about art and architectural practice and their relation to the production of public space.

The expanded field of spatial production is also the location of Ursula Biemann's work, an artist who works between geography and art in the video format. Her work engages critically with a range of disciplines and fields of knowledge, including feminist and post-colonial theory, ethnography, cultural and media studies and urbanism. Projects such as Sahara Chronicle (2006-2009) and Remote Sensing (2001) document spatial agency in unfamiliar contexts, whether it is the sub-Saharan migrations across Africa towards Europe or the territories of the global sex trade. Biemann spatialises the territorial and human relations in these situations, which are intricately linked to and influenced by the social and economic consequences of globalisation.

Other artists also work in fruitful collaborations with architects, such as the group of women artists and architects, Taking Place. Their work looks to define what a specifically feminist spatial practice could be. They have organised a number of events, from small gatherings to larger events hosted at institutions, involving students and members of the public. The events are a forum in which to discuss ideas and projects, as well as a chance for temporary transformations of space, for example lectures and talks occur in stairwells whereas lecture theatres become places to cook and impromptu performances are organised. Whether coming from an artistic or architectural point of view, taking place's practice is about conceptualising space as fluid, social and political, and as their name suggests, they start from the premise that 'places can simply be taken'.

Other collaborations between artists and architects include formal practices, such as muf and Public works, or informal networks that come together around specific projects, such as those initiated by Atelier d'Architecture Autogérée, Crimson, Exyzt, Raumlabor and others. Architects, such as Teddy Cruz and collectives such as Stalker / Osservatorio Nomade often work in collaboration with artists, whilst certain artists and artistic movements have had a large and direct impact on the practice of architecture, for example the Situationists, who have defined new directions for architecture that emphasise the everyday and the relationships between politics and cultural practice.

• Drop City

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'Marjetica Potrc', http://www.potrc.org/ [accessed 6 July 2010].

Marjetica Potrc, Urgent Architecture, Pap/DVD (LA: Palm Beach Institute of Contemporary Art, 2004).

Marjetica Potrc and Aisling O'Beirn, 'Tracking the Urban Animal', Circa, (2001): 26-29.

Craig Garrett and Thomas Hirschhorn, 'Thomas Hirschhorn: Philosophical Battery (interview)', Flash Art, (2004) http://www.papercoffin.com/writing/articles/hirschhorn.html [accessed 5 July 2010].

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Ursula Biemann, 'Remotely Sensed: A Topography of the Global Sex Trade', Feminist Review, 2005, 180-193.

Jan-Erik Lundstrom et al., Ursula Biemann: Mission Reports - Artistic Practice in the Field - Video Works 1998-2008 (Bristol: Arnolfini Gallery Ltd, 2008).

Benjamin Buchloh, 'Cargo and cult: The displays of Thomas Hirschhorn', ArtForum, 2001, http://findarticles.com/p/articles/mi_m0268/is_3_40/ai_81258058/?tag=content;col1 [accessed 4 July 2010].

Angela Dimitrakaki, 'Materialist Feminism for the Twenty-First Century: The Video Essays of Ursula Biemann', Oxford Art Journal, 30 (2007), 207-232.

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Marco Scotini, 'Dry Toilet', Domus, 891 (2006), 88-91.

N. Thompson, The Interventionists: Users' Manual for the Creative Disruption of Everyday Life (Cambridge, MA: MIT Press, 2004).

• Stealth.unlimited
• public works
• muf architecture/art
• The Anarchitecture Group
• Estudio Teddy Cruz (since 2012: Estudio Teddy Cruz + Forman)
• PS2
• Exyzt
• Raumlabor
• Constant Nieuwenhuys
• Jeanne van Heeswijk
• Caracas Think Tank
• Crimson Architectural Historians
• Atelier d'architecture autogérée
• Stalker/Osservatorio Nomade