CSG Calvijn

What CSG Calvijn does

CSG Calvijn, now operating as Portus Scholengroep since 2021, is a Dutch secondary education school group (not a commercial enterprise) governed by the Vereniging voor Christelijk Onderwijs in Rotterdam en omgeving (CVO), a Christian education association under Dutch law. The organization operates four core schools — Portus Meridiem (Rotterdam-Zuid), Portus Farelcollege (Ridderkerk), Portus Groene Hart (Barendrecht), and Portus Juliana (Rotterdam-Zuid, recognized four times as an 'Excellente school') — plus two cooperation schools (Focus Beroepsacademie and Máximacollege) and the De Binnenhaven facility for at-risk students. Collectively, these deliver the full spectrum of Dutch secondary education from vmbo-basis through vwo (atheneum), supplemented by bilingual education, sports programs, personalized coaching, and a specialized bridge between education and care.

The group's technology footprint centers on the Portus AI Vision Framework (2025-2028), which establishes six principles for responsible AI integration in education, and an AI-supported reading comprehension collaboration with NOLAI and Nestas. Practical AI deployment includes off-the-shelf tools such as Diffit (video transcription and quiz generation), ChatGPT (writing feedback), and Create.xyz (custom flashcard apps) for Dutch language instruction, alongside SharePoint-based staff portals and dedicated student/parent web portals (portal.calvijn.nl and ouder.cvo-portus.nl). The organization has no venture, private equity, or public ownership; it is funded through Dutch government education financing, parent contributions, and association-level administration.

Business model mechanics rely on standard Dutch secondary-education public funding channels coordinated via CVO Rotterdam, supplemented by tuition-related fees, partnership revenues (e.g., KoersVO consortium for De Binnenhaven, Enver for group training), and construction-related collaborations with Sportbedrijf Rotterdam and SARO for the new Meridiem campus. Goto-market is local and relationship-driven, relying on open days, school websites, school-specific Instagram channels, and direct parent communication rather than performance marketing. Revenue figures are not publicly disclosed.

Name

CSG Calvijn

Legal name

Portus scholengroep

Website

https://portusscholengroep.nl

Company type

Private

Founded year

2021

Operating status

Operating

Headcount range

101–250 employees

Short description

Portus Scholengroep (formerly CSG Calvijn) is a Dutch Christian secondary education school group operating four main schools plus two cooperation schools and a specialized at-risk-student facility across Rotterdam-Zuid, Barendrecht, and Ridderkerk under the CVO umbrella.

Ownership category

akta.pro rank

Product category

Secondary Education

NAICS

Other Schools and Instruction (6116)

SIC

Services-Educational Services (8200)

akta.pro primary industry

Special Education Online / Virtual Schools & Remote Programs (EDAKAAAL)

akta.pro secondary industry

K–12 SIS & District Administration Platforms (EDAFAEAA)

Keywords

• Secondary education
• Christian schools
• Vocational education
• Student support services
• VMBO HAVO VWO

GTM type

B2C

Offering type

Services

Cost components

Personnel, Operations, Technology or R&D, Infrastructure, Others

Distribution channels3 records

Marketing channels5 records

Core offering

CSG Calvijn (now Portus Scholengroep) operates a network of Dutch Christian secondary schools offering VMBO, HAVO, and VWO tracks, vocational education routes, and a dedicated at-risk student facility (De Binnenhaven). It also provides basic-skills programs (Basisvaardigheden) and school-based services through cooperation schools Focus Beroepsacademie and Máximacollege.

Product overview

Portus Scholengroep (the current name of the organization formerly known as CSG Calvijn) is a Dutch secondary education school group operating as a unified portfolio of schools and specialized programs. The core offering consists of four main schools — Portus Meridiem, Portus Farelcollege, Portus Groene Hart, and Portus Juliana — offering secondary education at all levels from vmbo-basis to vwo (atheneum), located in Rotterdam-Zuid, Barendrecht, and Ridderkerk. Supplementing the mainstream schools are two cooperation schools: Focus Beroepsacademie (vocational VMBO) and Máximacollege (practical education and Rebound). Beyond the schools, the group operates De Binnenhaven, a specialized facility for students aged 12-18 who are homebound or at risk of dropping out, providing education combined with coaching as a bridge between education and care. Additionally, the group provides a Basisvaardigheden (Basic Skills) platform for teachers to share resources on language, arithmetic, citizenship and digital literacy, and a three-year Begeleiding Startende Leraren (BSL) teacher induction program. Digital access is provided through a suite of portals: a Leerlingportaal (student portal), an Ouderportaal (parent portal), and a Medewerkersportaal (employee portal built on SharePoint).

Differentiator

Problem solved

Functional benefit

Products and services

• Portus Meridiem A core school within the Portus Scholengroep network delivering secondary education to students in the greater Rotterdam area.
• Portus Farelcollege Core school within the Portus Scholengroep network delivering secondary education; lineage traces back to 1920 as one of the group's predecessors.
• Portus Groene Hart Core school within the Portus Scholengroep network delivering secondary education to students in the region.
• Portus Juliana Core school within the Portus Scholengroep network delivering secondary education.
• Focus Beroepsacademie Cooperating school offering vocational/beroepsonderwijs pathways in cooperation with the Portus Scholengroep network.
• Máximacollege Cooperating school operating in cooperation with the Portus Scholengroep network to deliver secondary education.
• De Binnenhaven Dedicated facility within the group for at-risk students requiring specialized support and alternative secondary education pathways.
• Basisvaardigheden (Basic Skills program) Educational program focused on developing foundational/basic skills for students within the school group.

Quantifiable outcome

• 86% of colleagues see AI as an opportunity to enrich education, especially through personalization and direct feedback
• +2 more outcomes

Segments3 records

Ideal customer profiles1 record

Technology focussed No

API detail

Has API

No

API docs

API detail

Core technology

AI maturity

App detail

Feature3 records

Partnerships

Eight partnerships are on record, tiered core and minor.

• NOLAI and NestascoreTechnology or IntegrationCollaborative innovation project combining AI and reading comprehension in an AI-supported learning environment as part of the school's AI initiative.
• EnvercoreStrategic or Co-development PartnerCollaboration with Enver to provide group training for students at De Binnenhaven facility, combining education and care support.
• Opleidingsschool Rotterdam (OSR)coreStrategic or Co-development PartnerPortus is affiliated with Opleidingsschool Rotterdam which coordinates intensive cooperation with regional teacher training programs (HR, ICLON, TU Delft) for student teacher placements.
• Vereniging voor Christelijk Onderwijs Rotterdam en omgevingcoreOthersThe schools have long been part of the Christian Education Association in Rotterdam and surrounding areas, which now operates as CVO (Christelijk VO).
• CVO RotterdamcoreOthersCVO Rotterdam is the governing body overseeing Portus schools and administrative services including construction projects and staff management.
• Sportbedrijf RotterdamminorStrategic or Co-development PartnerCollaboration on new school construction project for Meridiem, located near De Kuip stadium area, as part of Stadionpark development.
• SAROminorStrategic or Co-development PartnerCollaboration on the new school complex construction project for Portus Meridiem opposite De Kuip.
• KoersVO ConsortiumcoreStrategic or Co-development PartnerDe Binnenhaven operates within the KoersVO consortium framework, serving students aged 12-18 with internalizing problems within this cooperation agreement.

Expansion highlights4 records

Direct peers

• Het Rijnlands Lyceum: Dutch foundation operating multiple secondary schools in Zuid-Holland with bilingual and international education programs. Comparable to Portus in offering bilingual and university-preparatory (vwo) tracks within a multi-school foundation structure, with similar scale.
• Stichting Salus: Smaller Dutch secondary school group operating in the Haarlem region with similar foundation structure and multi-school approach to Portus. Comparable in scale and educational level coverage (vmbo through vwo), though serving a different geographic area.
• LMC Voortgezet Onderwijs: Multi-school secondary education group operating in the Leiden region of Zuid-Holland with a comparable scale and foundation structure to Portus. Similar model of operating multiple schools offering different educational levels under a unified foundation umbrella.
• Stichting VCO Oost-Nederland: Multi-school secondary education group in eastern Netherlands operating under a Christian education foundation, similar to Portus's CVO affiliation. Comparable foundation structure, school portfolio approach, and educational philosophy rooted in faith-based values.

Broad incumbents

• Stichting Carmelcollege: One of the largest Catholic secondary school groups in the Netherlands with 13+ schools and approximately 20,000+ students across multiple regions. Comparable to Portus as a multi-school secondary education network operating under a foundation model, but significantly larger in scale and broader geographically.
• Quadraam: Established Dutch multi-school secondary education group based in Arnhem/Nijmegen region, operating under a foundation model. Similar in portfolio approach to Portus with diverse educational levels across multiple school locations, though broader in geographic scope.
• Stichting Dunamare: Large multi-school secondary education group based in Zuid-Holland region, the same province as Portus. Operates a similar foundation structure with multiple schools offering diverse educational levels, but at greater scale and with broader geographic reach across South Holland.

Others

• Stichting CVO Rotterdam: Parent organization and governing body of Portus Scholengroep, overseeing multiple school groups including Portus. Functions as umbrella administrator rather than a competitive peer, but provides relevant comparability on Dutch Christian education foundation governance models.
• NOLAI (National Education Lab AI): Dutch national laboratory for AI in education, established as a public-private partnership to develop AI applications for Dutch K-12 education. Listed as Portus's strategic partner on the AI-supported reading comprehension project, making them an ecosystem enabler rather than a direct competitor.

Regional players

• Stichting Etty Hillesum Lyceum: Single-school Dutch secondary education institution offering multiple levels with focus on bilingual and international education. Comparable to individual Portus schools in educational level offering and language programs, though operating as standalone rather than multi-school network.

Market position

Strengths5 records

Weaknesses5 records

Competitive moat4 records

Key risks6 records

Key highlights7 records

Customer concentration

• Instagraminstagram.com/farelcollege_ridderkerk
• LinkedInlinkedin.com/company/portusscholengroep

Revenue estimate

Valuation estimate

Number of profiles

Profiles2 records

Subsidiaries7 records

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 CSG Calvijn