What SLETH does

SLETH is a Danish architecture, landscape architecture, and urban planning firm headquartered in Aarhus, Denmark. Operating since approximately 2009, the firm delivers four interconnected service lines: architecture (residential, cultural, educational, and commercial buildings), urban planning and masterplanning, landscape architecture, and cultural heritage transformation / adaptive reuse. Its work spans Denmark, Norway, Finland, and France, anchored by a portfolio of international competition first prizes including Hovinbyen (Oslo, 1,100 acres), Refshaleøen (Copenhagen, 80 ha), Islev ID (Europan 11), Caen (France), and Designskolen Kolding (8,500 m²). The firm positions itself as bridging "progressive urban vision with consistent quality and sustainability in design realization."

SLETH serves three primary customer segments: municipalities and government entities (urban planning, public buildings, and civic infrastructure), cultural and educational institutions (schools, universities, museums, churches), and real estate developers (residential and mixed-use urban districts). Revenue is generated through architectural competitions, direct commissions, and public tender processes, with project pricing varying by scope, location, and client requirements and not publicly disclosed. The firm maintains long-standing partnerships with engineering and architecture peers including Ramboll, COWI, Søren Jensen, COBE, Cubo, SLA, and Realdania, enabling it to assemble multidisciplinary teams for large-scale urban transformation briefs.

The firm operates a small team (11–50 employees) and pursues R&D-led differentiation, notably through the Hyphen Board sustainable material co-developed with Horn Bordplader and the Genbrug på matriklen circular-design research project completed in 2025 with Aarhus School of Architecture and Realdania. Brand visibility is sustained primarily through earned media in Danish architecture publications such as Arkitekten and Politiken rather than through paid marketing channels. SLETH is privately held with no disclosed parent company, subsidiaries, external investment, or public listing.

Name

SLETH

Legal name

SLETH Office for architecture and planning

Website

https://sleth.dk

Company type

Private

Founded year

2009

Operating status

Operating

Headcount range

11–50 employees

Short description

SLETH is a Danish architecture, landscape, and urban planning firm based in Aarhus, delivering building design, masterplanning, and cultural heritage transformation for municipalities, cultural institutions, and real estate developers across Denmark, Norway, Finland, and France.

Ownership category

akta.pro rank

Headquarters

HQ city

Aarhus

HQ country

Denmark

HQ region

Europe

Offices1 record

Markets served

GTM type

B2B

Offering type

Services

Cost components

Personnel, Operations, Marketing or Sales, Technology or R&D, Infrastructure

Distribution channels1 record

Marketing channels2 records

Core offering

SLETH is a Danish office for architecture, landscape, and urban transformation providing building design, urban masterplanning, landscape architecture, and cultural heritage adaptive reuse services. The firm delivers projects from concept through realization across Denmark and internationally, with an emphasis on sustainable design and consistent quality. Its core client base includes municipalities, cultural and educational institutions, and real estate developers.

Product overview

SLETH is a Danish office for architecture, landscape and urban transformation. The firm operates as a service-based practice offering four interconnected service lines: Architecture Services (design of internationally recognized buildings including residential, cultural, educational, and commercial projects), Urban Planning Services (strategic masterplanning and urban transformation for large-scale territories and city districts), Landscape Architecture Services (design of public and private outdoor spaces), and Cultural Heritage Transformation (adaptive reuse of heritage buildings). The firm's work bridges progressive urban vision with consistent quality and sustainability in design realization, spanning projects from Denmark to Norway, Finland, France, and internationally.

Differentiator

Problem solved

Functional benefit

Products and services

• Architecture Services Design and realization of internationally recognized buildings, encompassing residential, cultural, educational, and commercial architecture projects across Denmark and internationally for municipalities, institutions, and private developers.
• Urban Planning Services Strategic urban transformation and masterplanning services, including city district development, urban renewal, and comprehensive planning for large-scale territories, delivered to municipalities and public-sector clients.
• Landscape Architecture Services Landscape design and transformation projects, ranging from public squares and parks to private gardens and urban green spaces, delivered as part of an integrated architecture and planning practice.
• Cultural Heritage Transformation Services Adaptive reuse and transformation of cultural heritage buildings, preserving architectural legacy while enabling new contemporary functions, for municipalities and cultural institutions.

Quantifiable outcome

• Shared 1st prize in open competition for Refshaleøen 2024 (80ha)
• +3 more outcomes

Segments3 records

Ideal customer profiles3 records

Technology focussed No

API detail

Has API

No

API docs

API detail

Core technology

AI maturity

App detail

Feature1 record

Partnerships

16 partnerships are on record, tiered core, major, innovation, research and regular.

• COBEcoreStrategic or Co-development Partner · 1 January 2009Won international competition for Copenhagen North Harbour urban development in 2009. Continued collaboration on urban space projects including Sandkaj Brygge and Göteborg Plads. Long-term strategic partnership in Danish urban development projects.
• RambollcoreStrategic or Co-development Partner · 1 January 2009Part of the winning team for Copenhagen North Harbour competition. Ongoing collaboration on urban planning and development projects.
• CubomajorStrategic or Co-development PartnerCollaboration on multiple projects including Designskolen Kolding (1st prize 2022), Frederiksberg Haver development plan, and other architectural competitions.
• Søren Jensen Rådgivende IngeniørfirmamajorStrategic or Co-development PartnerLong-standing collaboration on numerous projects including Tønder Townhall, Ny Vesterport, Testrup Højskole, and the Hyphen board sustainable materials development project.
• COWImajorStrategic or Co-development PartnerCollaboration on Aarhus K development plan (2013-2014) and other large-scale urban planning projects.
• SLAmajorStrategic or Co-development PartnerCollaboration on Amtssygehuset transformation project (2016-2017), bringing together landscape and architectural expertise for hospital-to-urban-district conversion.
• MoemajorStrategic or Co-development PartnerPartnership on Amtssygehuset transformation and other urban development projects.
• Horn BordpladerinnovationStrategic or Co-development PartnerCollaboration on Hyphen Board development - a regenerative board material that replaces particle boards 1:1, consisting of 50% mycelium and 50% organic substrate, 100% compostable with 0 kg CO₂-eq/m³ emissions.
• RealdaniamajorStrategic or Co-development PartnerFunded and partnered on Blåvand Masterplan and Genbrug på matriklen research project (led by Aarch). Major Danish foundation supporting urban development and architectural innovation.
• Varde MunicipalitycoreStrategic or Co-development PartnerInitiator and partner on Blåvand City Center Masterplan project. Public-private collaboration for sustainable tourism destination development.
• Urban CreatorsmajorStrategic or Co-development PartnerCollaboration on multiple projects including Amtssygehuset transformation, Blåvand Masterplan, and Lillebæltskvarteret parallel assignment.
• Aarhus School of Architecture (Aarch)researchStrategic or Co-development PartnerLead partner on Genbrug på matriklen research project (2025) focusing on circular design and material reuse in urban development.
• Lafayette ConsortiummajorStrategic or Co-development PartnerTeam lead for Grand Porte des Alpes urban study (Lyon, France 2022-2023) spanning Bron, Saint-Priest and Chassieu municipalities, addressing climate change and urban development.
• Rasmus Hjortshøj / COASTregularStrategic or Co-development PartnerPrimary photography collaborator on numerous projects including Göteborg Plads, Tønder Townhall, Æggepakkeriet, and other completed works.
• Skaarup LandskabmajorStrategic or Co-development PartnerLandscape architecture collaboration on Blåvand City Center Masterplan and construction project.
• MOEmajorStrategic or Co-development PartnerEngineering collaboration on Frederiksværk Stålsatte Byrum (1st prize) and Frederiksberg Haver development plan.

Scale indicators3 records

Recent moves6 records

Expansion highlights5 records

Broad incumbents

• Snøhetta: Norwegian-origin international architecture and landscape practice. Competes with SLETH on Nordic cultural and urban projects (e.g., Helsinki Central Library where SLETH submitted in 2012), but at much larger scale.
• MVRDV: Dutch architecture firm with strong European urban planning and masterplanning portfolio. Comparable design language on large-scale mixed-use and urban projects, but operates at significantly larger scale and global reach.
• Henning Larsen: Nordic-rooted architecture firm (now part of Ramboll Group). Competes for the same cultural, educational, and urban projects in Scandinavia and beyond; Ramboll ownership makes it a structural competitor and former collaborator context for SLETH.
• BIG (Bjarke Ingels Group): Much larger Danish-headquartered architecture firm with global practice. Competes for the same international cultural and urban mandates (e.g., Refshaleøen-area work in Copenhagen) but operates at vastly greater scale and brand reach.
• 3XN: Established Danish architecture firm with global footprint. Overlaps with SLETH on cultural buildings, masterplans, and sustainability-focused design but is significantly larger and more diversified across typologies.

Direct peers

• COBE: Danish architecture and urban planning firm of comparable size that co-bid the Copenhagen North Harbour competition with SLETH in 2009 and continues collaborating. Most direct peer: same Nordic design culture, urban transformation focus, and competition-driven business model.
• C.F. Møller Architects: Scandinavian architecture firm with similar mid-size scale, urban planning and landscape capabilities, and a strong Danish/Nordic competition track record. Directly comparable on services, geography, and client segments (municipalities, cultural institutions, developers).
• Dorte Mandrup: Danish architecture studio with comparable size and profile, focused on cultural buildings, climate-responsive design, and competition-led commissions. Competes for the same municipal and cultural commissions in Denmark and abroad.
• SLA: Danish landscape architecture firm that partnered with SLETH on Amtssygehuset (2016-17). Direct peer for SLETH's landscape service line, with overlapping urban and public-space commissions and similar Nordic client base.

Emerging players

• ADEPT: Danish architecture and urban planning office with comparable size and a focus on sustainability, urban transformation, and competition-led commissions. Direct emerging competitor on Nordic municipal and developer projects.

Market position

Weaknesses5 records

Competitive moat3 records

Key risks2 records

Key highlights6 records

Customer concentration

• LinkedInlinkedin.com/company/sleth-a-s

Revenue estimate

Valuation estimate

Number of profiles

Funding overview

Funding rounds

Investors

Funding detail is available on the Subscription and Enterprise plan.Contact sales →

M&A

Investments

M&A and investment is available on the Subscription and Enterprise plan.Contact sales →

Frequently asked questions about SLETH