51N4E
51N4E is a Brussels-based architecture and urban design practice with 44 staff, delivering adaptive reuse, public-space, and hybrid-building projects for governments, real estate developers, and cultural clients across Europe and Albania.
- Company typePrivate
- Founded2001
- HeadquartersBrussels, Belgium
- Headcount11–50
- GTM typeB2B
- OfferingServices
What 51N4E does
51N4E is a Brussels-headquartered architecture and urban design practice founded in 2001 and organised through two Belgian legal entities (51N4E Acte bv and 51N4E Cast bv), with a team of 44 professionals led by 11 partners including co-founders Johan Anrys and Freek Persyn. The firm operates across multiple thematic programmes — Open Public Structures, Metropolitan Hybrids, Performative Landscapes, Adaptive Infrastructure, Transformative Densification, Civic Design, and Nature and Buildings — and is establishing a third studio, Root, as a structural collaboration with landscape partner Plant & Houtgoed.
The practice's core offering is project-based professional services spanning architectural design, urban planning, landscape architecture, design research, and project coordination, executed through a proprietary 'Design in Dialogue' methodology that treats architecture as a collaborative learning process with stakeholders. Technical capabilities are concentrated in adaptive reuse, circular-economy material sourcing, hybrid building typologies, and participatory public-space design, evidenced by projects such as the ZIN in No(o)rd reuse of WTC towers for Befimmo, the Skanderbeg Square restructuring in Tirana, the Victoria refurbishment in Brussels, and material-salvage initiatives like Track and Recypark.
Revenue is generated through architecture competitions (open and invited), public procurement, and direct commissions from institutional and enterprise clients. The client base spans city and regional governments across Belgium, France, Albania, Switzerland, the Netherlands, Luxembourg, and Turkey, as well as real estate developers, cultural operators, and social-sector organisations. Distribution is direct-enterprise: the firm relies on competition wins, invited bids, civic self-initiated programs (Lab North, Archiweek), academic positions, and a portfolio-driven website rather than commercial marketing channels. No revenue, ARR, or fee figures are publicly disclosed.
51N4E firmographics
Firmographics- Name
- 51N4E
- Legal name
- 51N4E Acte bv
- Website
- https://51n4e.com
- Company type
- Private
- Founded year
- 2001
- Operating status
- Operating
- Headcount range
- 11–50 employees
- Short description
- 51N4E is a Brussels-based architecture and urban design practice with 44 staff, delivering adaptive reuse, public-space, and hybrid-building projects for governments, real estate developers, and cultural clients across Europe and Albania.
- Ownership category
- akta.pro rank
51N4E industry classification
Industry- Product category
- Architecture Services
- NAICS
- Architectural Services (54131), Landscape Architectural Services (541320), Architectural, Engineering, and Related Services (5413)
- akta.pro primary industry
- Landscape Architecture & Site Design (BPAHAKAC)
- akta.pro secondary industry
- Community Engagement & Participatory Planning (BPAHAKAO)
Keywords
Where 51N4E is headquartered
LocationHeadquarters
- HQ city
- Brussels
- HQ country
- Belgium
- HQ region
- Europe
Offices1 record
Markets served
51N4E business model
Business model- GTM type
- B2B
- Offering type
- Services
- Cost components
- Personnel, Operations, Technology or R&D, Marketing or Sales, Others
Revenue model
- Architecture and Urban Design Services: 51N4E generates revenue through commissions for architectural design, urban planning, and landscape design services on large-scale projects for public and private clients. Revenue is project-based, sourced from architecture competitions, invited competitions, public procurement, and direct commissions. Services include full process involvement from design through execution, design research, and project coordination.
Go-to-market motion1 record
Distribution channels3 records
Marketing channels5 records
51N4E product offering
Product offeringCore offering
51N4E is an architecture and urban design practice that delivers architectural design, urban planning, landscape architecture, and spatial transformation services for public and private institutional clients. Services cover the full project lifecycle from design through execution, including design research, project coordination, adaptive reuse of existing buildings, circular construction, and participatory urban design, delivered across multiple studios (Acte, Cast, Root) and thematic programmes.
Product overview
51N4E is an architecture and urban planning practice based in Brussels, Belgium. The firm does not offer software products or technology platforms. Its services consist of architectural design, urban planning, landscape architecture, and spatial transformation projects delivered through design consultancy and project management. The practice organizes its work across multiple studios (Acte, Cast, Root) and several thematic programmes including Open Public Structures, Metropolitan Hybrids, Performative Landscapes, Adaptive Infrastructure, Transformative Densification, Civic Design, and Nature and Buildings.
Differentiator
Problem solved
Functional benefit
Products and services
- Architectural Design Services
Quantifiable outcome
- The Victoria refurbishment achieves fossil-free, low-energy building transformation while maximizing material reuse
- +4 more outcomes
Companies that use 51N4E
Customer profileNamed customers10 records
Segments3 records
Ideal customer profiles3 records
51N4E technology and API
TechnologyTechnology focussed No
API detail
- Has API
- No
- API docs
- API detail
Core technology
AI maturity
App detail
Feature4 records
51N4E partnerships and signals
Strategic signalPartnerships
Nine partnerships are on record, tiered core and minor.
- Plant- en HoutgoedcoreLandscape architecture partner collaborating across numerous projects including ZIN in No(o)rd, Victoria, Skanderbeg Square, and Thurgauerstrasse. Also co-developing Root — a new structural collaboration between 51N4E and Plant & Houtgoed as a separate studio entity.
- Architecture Workroom BrusselscoreResearch and advocacy organization with which 51N4E collaborates on urban studies and conceptual research. Collaborated on Lerend Landschap (Campus Bret, Genk), Test Site Istanbul, and the Lab North initiative.
- ATAMA and V+ (Temporary Association)coreTemporary association of three firms (51N4E, ATAMA, V+) formed for the Van Praet project to develop and coordinate three zones of the ZIR 4 masterplan in Brussels.
- Lacaton & VassalcoreRenowned French architecture firm collaborating with 51N4E on the Peterbos 9 social housing renovation project in Anderlecht, Brussels.
- Up4NorthminorNetwork organization involved in the Lab North initiative, contributing to temporary uses of WTC1 and CCN spaces in Brussels' North Quarter.
- Plan Común, Lafayette, Etablissement, Atmos Lab, and others (Consortium)coreLarge multidisciplinary consortium for the Quartiers de Demain competition in Pessac, France. 51N4E leads the architecture and urban design aspects of the Domofrance refurbishment project.
- l'AUC and Jaspers-EyerscoreCollaboration on the ZIN in No(o)rd project for Befimmo NV — l'AUC and Jaspers-Eyers serve as co-architects alongside 51N4E for the WTC towers reuse project.
- GRAUcoreArchitecture and urban design firm collaborating with 51N4E on the Portes Métropolitaines study for Bordeaux Métropole, focusing on transformation of six key gateways along the metropolitan ring road.
- Chevalier MassonminorTextile designer co-designing elements for the Tous Ensemble care center project, contributing to the interior and fabric design.
Scale indicators3 records
Recent moves6 records
Expansion highlights5 records
51N4E competitors and assessment
Company assessmentMarket position
Competitive moat5 records
Key risks5 records
Key highlights7 records
Customer concentration
51N4E social profiles
Digital presence51N4E financial estimates
Financial estimateRevenue estimate
Valuation estimate
51N4E leadership team
Management profileNumber of profiles
Profiles11 records
51N4E funding detail
Funding detailFunding overview
Funding rounds
Investors
Funding detail is available on the Subscription and Enterprise plan.Contact sales →
51N4E M&A and investment
M&A and investmentM&A
Investments
M&A and investment is available on the Subscription and Enterprise plan.Contact sales →
Frequently asked questions about 51N4E
What does 51N4E do?
51N4E is an architecture and urban design practice that delivers architectural design, urban planning, landscape architecture, and spatial transformation services for public and private institutional clients. Services cover the full project lifecycle from design through execution, including design research, project coordination, adaptive reuse of existing buildings, circular construction, and participatory urban design, delivered across multiple studios (Acte, Cast, Root) and thematic programmes.
Is 51N4E a public or private company?
51N4E is a private company. It is classified as founder individual operated bootstrapped and is currently operating.
When was 51N4E founded?
51N4E was founded in 2001. It employs 11 to 50 people.
Where is 51N4E based?
51N4E is headquartered in Brussels, Belgium, in the Europe region.
How does 51N4E make money?
One revenue line is on record: architecture and Urban Design Services.
Does 51N4E have an API?
No public API is recorded for 51N4E.
What industry is 51N4E in?
51N4E's product category is Architecture Services. Its primary akta.pro industry code is BPAHAKAC, Landscape Architecture & Site Design, with a secondary code of BPAHAKAO, Community Engagement & Participatory Planning. Its NAICS code is 54131.