Modern life rarely organises itself neatly by age. In workplaces, communities and families, we interact constantly with people older and younger than ourselves. Experience flows in multiple directions; leadership emerges in unexpected places.

Schools, by contrast, remain one of the few environments still structured almost entirely around rigid age cohorts.

Students move through year groups like through carriages on a train: Year 7, then Year 8, then Year 9, and so on, largely insulated from the others.

It is tidy and administratively convenient. But if the world our students are entering is not organised this way, it raises an important question: why are our schools?

In August 2025, at Kinabalu International School (KIS), a small- to medium-sized international school with just under 500 students from early years foundation stage to Year 13, we decided to challenge the status quo.

Vertically structured groups

We moved away from tutor groups based purely on age and instead introduced vertically structured house groups that we have called Sakags - a local Kadazan-Dusun word meaning “family” or “tribal unit”.

The change was not driven by novelty. It stemmed from a simple question: if schools exist to develop young people as citizens, not just pupils, how intentionally are we designing the structures that shape their daily experience?

Sakags are built upon the school’s traditional house system, with all students belonging to one of three houses (Gaya, Sapi or Sulug - each named after a prominent regional island). Within this structure, students are further grouped into Sakags by age, with one set for Years 7-9 and another for Years 10-13.

Each Sakag spans backgrounds, abilities, nationalities and lived experience, with the intention to create daily, structured opportunities for students to interact meaningfully with others who are not the same age, stage or social circle as themselves.

For example, while registration time remains familiar -15 minutes each morning to look ahead to the day and week - its content is now deliberately broadened. Students discuss global events, ethical questions, leadership issues and the practical realities of school life together, across ages.

More significantly, one to two hours every Friday afternoon is dedicated exclusively to global citizenship time. All students come off timetable in their Sakags to engage in inter-house collaboration, leadership projects, service learning, competition, reflection and dialogue linked to our core values.  

This allows leadership to emerge in unexpected places. Leadership is not confined to the oldest students. Younger pupils lead discussions, organise activities and contribute ideas, while older students learn mentoring, restraint and responsibility.

Teacher responsibilities

Of course, managing this requires some extra focus from teachers beyond simply ticking off names in registration.

This model asks more of teachers than a traditional tutor role. Each Sakag is led by a “House Parent”, supported by others, with responsibility for pastoral oversight, wellbeing and the overall culture of the group.

For many staff, moving from a single year group to a vertically mixed Sakag required adjustment, and it was initially met with some hesitancy. However, this was carefully framed as a values-led shift rather than change for its own sake.

In practice, it has brought clear benefits: a more equitable distribution of students across staff, greater staff involvement in pastoral care, and stronger relationships through improved staff-to-student ratios.

In the early stages, teachers played a more directive role, guiding students in how to collaborate across age groups. Increasingly, however, their role has shifted towards facilitation, with student leadership and dialogue taking the lead.

Initial scepticism, particularly from older students, has given way to strong support, with many recognising the value of broader relationships and more meaningful opportunities for leadership.

Getting it right

However, vertical systems are not a panacea. I have seen them implemented exceptionally well at other schools, and very poorly, too. The difference is rarely structure but the “why”.

Where vertical groups become performative - assemblies without substance, competitions without purpose - they falter. Where they rely excessively on charismatic individuals rather than a shared framework, they struggle to sustain impact.

Scale also matters. Vertical models work best in schools that are small enough for relationships to remain authentic. Once institutions become too large, the intimacy required for genuine collegiality is harder to maintain.

When done well, however, the outcomes are profound. Barriers between students soften. Parents connect across year groups. Leadership becomes distributed rather than hierarchical. Service learning becomes embedded rather than episodic.

Most importantly, students experience daily what it means to belong to a community larger than themselves.

Education, at its best, is not simply transactional. It is transformational. Vertical house groups (our Sakags), thoughtfully designed and purposefully led, can help schools live that belief.

Sam Gipson is principal of Kinabalu International School in Malaysian Borneo and chair of AIMS (Association of International Malaysian Schools)