SLETH is an architecture office working within the field of architecture, urbanism and landscape design. Our approach to practice can be described as architectural planning – bridging the gap between progressive urban visions and consistent quality in the design realisation. SLETH is lead and owned by architects Søren Leth and Rasmus Therkildsen.

Based in Denmark with offices in Aarhus and Copenhagen, SLETH maintains an international approach to practice, participating in international competitions, venues, exhibitions and academia.  Since 2009, SLETH has won numerous international competitions and awards, from Copenhagen Northharbour Masterplan, Europan 12 and Tonder Townhall. Recently the office won 1. prize in Hovinbyen, the expansion of Oslo Norway, and the regeneration of Slagelse town.

The multidisciplinary identity allows SLETH to develop a thinking that is willing to accept territorial complexity, drawing on historic references and precise analytic work. The workshop atmosphere at SLETH combines a professional attitude with an open-minded, visionary ambition. SLETH currently has 30 qualified people in the office, ranging from experienced building architects, planners and landscape architects. The company is operating projects that range geographically and by type, working with public and private organisations as well as privately held companies and independent contractors.

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Since 2009, SLETH has produced a number of prize winning competition entries and realised projects. During the same time SLETH has received several honors and architecture awards. Recently, SLETH was awarded Scandinavia´s largest architecture prize, Nykredits Motivation Prize in May 2016.

2016 Receiver of Denmark’s largest architecture prize – Nykredit Motivation Prize
2014 Receiver of grant for development of scenarios for Denmark 2050, the Danish Art Foundation
2013 Receiver of the Danish Art Foundation grant 2013

2016 1. prize in invited competition for urban development of Campus Slagelse. DK
2015 1. Prize in open international competition for expansion of Oslo, 1100 ha. NO
2014 1. Prize in invited competition for urban development of Frederiksværk. DK
2013 2. Prize in open international competition for the expansion of Hillerød South. DK
2013 1. Prize in open international competition for the extension of Tønder Townhall. DK
2013 1. Prize in invited competition for urban development of Albertslund, Hersted Industrial Park. 170 Ha. DK
2012 1. Prize in open international competition, Europan 11, Islev ID, Rødovre. DK
2011 1. Prize in invited competition for urban development project ‘Caen Presqu’île’. FR
2010 Finalist. National Museum Norway, Oslo. Project Urban Canvas. NO
2009 1. Prize Northharbour, Copenhagen. 350 ha master plan. International competition. DK
2008 1. Prize in an invited competition for a new cultural center Aarhus. Built 2008. DK
2007 1. Prize in an invited competition 430 ha. masterplan Hornshøj, Holstebro. DK



Søren Leth (born 1975) is the founder of SLETH and responsible for tasks in architecture, urban development and concept development. In addition, Søren is responsible for presentation of the company’s projects. He has extensive experience in leading strategic and creative processes with a high degree of complexity. Søren is also often used as a speaker and participant at conferences, workshops and other events.

Søren has a Master in architecture and urban planning from the School of Architecture in Aarhus. He has previously worked as a project manager with international urban projects with large public and private clients, including The Danish Building & Property Agency, CPH City and Port and various Danish municipalities. In addition, he has been affiliated with the Academy Council and for years taught at the School of Architecture in Aarhus and is designated as examiner.

Søren is an appointed member of the Danish Arts Foundation’s Committee for Architecture 2014-2017.



Rasmus Therkildsen (born 1975) has since 2009 been the one half of SLETH and is responsible for tasks in architecture and concept development – in addition Rasmus is responsible for the company’s strategic development. Based on his experience with construction management, Rasmus is currently overseeing several of Sleths building projects under realisation.

Rasmus has a Master in architecture and art from the School of Architecture in Aarhus. He previously worked as a project manager until 2004 where he started his own practice. He has the past 10 years worked within the field of architecture, concept development and strategic planning in different contexts and constellations. Rasmus is concerned with entrepreneurship and is associated as a mentor in the greenhouse Ark: Idea at Aarhus School of Architecture, at the same time being associated with Aarhus School of Architecture and Aalborg University as a censor.

Rasmus is a member of The National Association of Building and Landscape Culture´s Committee for Recent Architecture.


2016 First buildings realised, Tønder Townhall and Sonnesgade 11
2015 First urban space projects realised, Silo Plaza and Valsetorvet
2012 Recipient of Danish Arts Foundation grant
2010 Published first monograph, Sleth Modernism Selected Projects 2005-2010
2009 Foundation of SLETH A/S
2009 First Prize in Northharbour competition
2006 Foundation of SLETH

● Sonnesgade 11, Aarhus DK
● Tønder Townhall, Tonder DK

● Silo Plaza, Copenhagen DK
● Valsetorvet, Frederiksværk DK

● North Harbour, Copenhagen DK