The previous piece in this pillar laid out the headline numbers. Two British children at a top Bangkok international school for 13 years each costs £480,000-£760,000. Same family in Singapore: £780,000-£1 million. The choices British expat families normally make are between premium and slightly less premium, between for-profit and non-profit, between American curriculum and British curriculum.

There’s another option most British families never seriously consider. The bilingual middle ground.

These are schools that charge £4,000-£12,000 a year, teach a curriculum that combines local language and English-medium instruction, hire foreign teachers alongside local ones, and produce students who go on to UK, Australian, American, and regional universities. Two children for 13 years at a quality bilingual school costs £200,000-£300,000 total. That’s £500,000-£700,000 less than the equivalent premium international school. It is, by any reasonable analysis, the single most consequential cost-saving decision available to a British family in Asia.

And almost nobody talks about it.

Today’s piece is the deep look at why these schools exist, what they actually deliver, who they’re best for, and the structural reasons British expat families have been steered away from considering them. The honest answer matters because the maths involves enough money to fund two university educations, an early retirement, or a UK property purchase.

What a bilingual school actually is

The term “bilingual school” covers a wide range of institutions, and the variation matters. In the Southeast Asian context, the main models are:

Local-curriculum bilingual schools teach the national curriculum (Thai, Vietnamese, Indonesian) with substantial English-medium instruction in subjects like maths, science, social studies, and English language. Sarasas Ektra in Bangkok is the classic example, teaching the Thai Ministry of Education curriculum bilingually since 1995. Students take the Thai national examinations alongside English-medium content.

International-curriculum bilingual schools teach a Western or international curriculum (British IGCSE/A-Level, IB, American) but include significant local language instruction. BVIS Hanoi (Nord Anglia’s bilingual sister school to BIS Hanoi) is the model here, teaching the British curriculum with substantial Vietnamese language and culture integration. Students exit with British qualifications and a working command of Vietnamese.

Trilingual schools like Singapore International School Bangkok (SISB) layer in a third language (often Mandarin) alongside English and the local language. Students take Singaporean curriculum examinations, IGCSE, and A-Level at the senior end.

Catholic and church-affiliated bilingual schools exist across the region as a separate tradition, often charging less than secular bilinguals while delivering comparable academic quality. Several of Bangkok’s Catholic schools fit this category, with strong English-medium instruction and university progression records.

The diversity matters because the bilingual category is not a single product. A school like BVIS Hanoi is closer to a premium international school in feel and outcomes than to a true local-curriculum bilingual. A school like Sarasas Ektra is closer to a high-quality local school with English-medium instruction than to BVIS. Both can be excellent. They serve different families.

The Bangkok bilingual landscape

Bangkok has the largest and most developed bilingual school market in Southeast Asia. The pricing splits roughly into three bands.

Established bilingual mid-tier (£6,000-£12,000 per year):

  • Sarasas Ektra School (founded 1995): Thailand’s pioneer bilingual school. Catholic, co-educational, three campuses in Yannawa district. Fully bilingual instruction in Thai and English from kindergarten through Year 12. Senior students can take the school’s “Extra Class” programme or the externally-accredited Global Assessment Certificate (GAC), which preparing them for international university entry. ACT Education Solutions oversees the GAC programme globally and the certificate is recognised for university applications in the US, UK, Canada, and Australia. Fees: roughly THB 200,000-280,000 (£4,650-£6,500) per year.

  • Wells International School: established Bangkok school with a British-aligned curriculum, fully English-medium with strong international university outcomes. Fees: roughly THB 400,000-650,000 (£9,300-£15,100). Sits between true bilingual and full international school.

  • Singapore International School Bangkok (SISB): founded 2001, five campuses across Bangkok and Chiang Mai, trilingual programme in English, Chinese, and Thai. Students take Singapore iPSLE, IGCSE, and A-Level. Fees: roughly THB 350,000-550,000 (£8,100-£12,800).

Established bilingual lower-tier (£4,000-£8,000 per year):

  • Sarasas Witaed Suksa and the broader Sarasas group: 24 affiliated schools, 15 of them bilingual. Lower fees than Sarasas Ektra (the flagship), still solid academic outcomes. Fees: roughly THB 150,000-220,000 (£3,500-£5,100) per year.

  • Triamudom Suksa Pattanakarn: bilingual programme of one of Thailand’s most prestigious national schools. Highly competitive entry, lower fees, exceptional Thai university placement. Less English-medium than Sarasas but strong outcomes.

  • Various Catholic schools (Assumption College, St Joseph Convent, Mater Dei): traditional Bangkok bilingual schools with strong reputations, particularly for families with Catholic backgrounds. Fees vary by campus but generally THB 100,000-250,000 (£2,300-£5,800) per year.

Newer hybrid options (£8,000-£15,000):

  • BVIS-style sister schools of premium Nord Anglia or Cognita brands, offering the international curriculum at a bilingual price point. Variable by school.

For a family choosing Sarasas Ektra or SISB over Bangkok Patana, the saving over 13 years per child is roughly £170,000-£220,000. For two children, £340,000-£440,000. This is the practical Vietnam Window equivalent for education, a window where the maths favour the cheaper option, while the academic outcomes remain comparable.

The Hanoi bilingual landscape

Hanoi is a smaller and less developed bilingual market than Bangkok, but the same logic applies.

Vinschool: Vietnam’s largest private bilingual school network, founded by Vingroup. Multiple campuses across Hanoi and HCMC. Bilingual instruction in Vietnamese and English, with the option of a fully international curriculum stream (Cambridge IGCSE) at senior levels. Fees: roughly VND 100-200 million (£3,200-£6,400) per year for the bilingual track, VND 200-400 million (£6,400-£12,800) for the Cambridge IGCSE track. Strong Vietnamese university placement, growing international progression.

BVIS Hanoi (covered yesterday): the bilingual sister of BIS Hanoi, full British curriculum with Vietnamese language integration. Fees USD 10,000-20,000 (£7,900-£15,800). Bridges the gap between true bilingual and full international.

Olympia Schools: established Hanoi network with bilingual and international streams. Mid-tier pricing, strong reputation among the growing Vietnamese middle class.

Wellspring Hanoi: Cambridge-curriculum bilingual school, growing reputation, fees roughly VND 250-450m (£8,000-£14,400) per year.

For a British family in Hanoi, the choice between BVIS (USD 10-20k) and BIS (USD 18-28k) saves roughly £100,000-£150,000 per child over 13 years. The choice between Vinschool’s Cambridge stream (£6-13k) and BIS (£14-22k) saves roughly £150,000-£200,000 per child. These are not theoretical numbers. They are the actual difference between Vietnamese bilingual education and Western premium international education in the same city.

Kuala Lumpur, Ho Chi Minh, and the regional picture

Briefly, because the pattern repeats:

Kuala Lumpur: Excellent bilingual options including Sri KDU schools, Cempaka Schools, and the various international schools that offer bilingual tracks at lower price points than their pure English-medium streams. Fees: RM 30,000-60,000 (£5,400-£10,800) per year for strong bilingual options.

Ho Chi Minh City: similar to Hanoi. Vinschool and BVIS HCMC are the main mid-tier options. Local elite bilingual schools (Le Quy Don, ISHCMC American Academy) offer further options.

Singapore: this is where the comparison breaks down. Singapore’s local government schools are world-class (Singapore consistently tops PISA rankings) but generally not accessible to non-resident foreigners. The bilingual middle ground that exists in Bangkok and Hanoi essentially doesn’t exist in Singapore for British expat families. This is one of the reasons Singapore’s international school market is so expensive: there’s no genuine alternative.

The structural objections (and what’s actually true)

When British families consider bilingual schools, they usually run into four objections. Some are real. Some are overstated.

Objection one: “The English-medium teaching isn’t strong enough.”

Reality: this varies enormously by school. At schools like Sarasas Ektra, SISB, BVIS, or Vinschool, English-medium instruction is delivered by qualified foreign teachers in 50-70% of academic subjects. Students graduate with genuine working command of English, typically at IELTS 6.5-7.5 level by Year 13. They take international qualifications (GAC, IGCSE, A-Level, Cambridge) in English.

At lower-tier bilingual schools, English instruction can be patchier. Foreign teacher turnover is higher. Quality of English-medium content can be variable. The diligence required to choose the right bilingual school is real and not trivial. It is, however, the same diligence required to choose the right international school. There is no school category in Asia where you can outsource the assessment entirely to the brand.

Objection two: “University outcomes will suffer.”

Reality: this is largely a myth. The GAC programme at Sarasas Ektra has placed students at universities including Imperial College London, UCL, ANU, University of Melbourne, McGill, and various US institutions. SISB students routinely progress to UK Russell Group, Singaporean universities, and Asian top-50 institutions. Vinschool’s Cambridge IGCSE graduates have gone to UK universities including Cambridge itself.

The university outcomes question depends on two factors: the academic quality of the school (which can be assessed) and the academic quality of the child (which is independent of the school choice). A motivated bilingual-school student with strong IGCSE/A-Level grades has the same UK university options as a motivated international-school student. The difference is whether the family wants to pay an extra £400,000 for the same end result.

Objection three: “The peer group will be different.”

Reality: this is true and not necessarily negative. At a premium international school, your child’s peers will be predominantly other expatriate children plus wealthy local families. At a bilingual school, your child’s peers will be predominantly local children plus a smaller expatriate contingent.

For some families, the international school peer group is part of the value proposition (English-language friendship networks, expat community continuity, easier social integration). For others, the bilingual school peer group is a benefit (genuine cultural immersion, lifelong local language skills, integration into the country your family has chosen to live in).

A British child who spends 13 years at Sarasas Ektra emerges fluent in Thai, with Thai friendships, with deep understanding of Thai culture, and with the same university options as their international-school peers. A British child who spends 13 years at Bangkok Patana emerges with strong English-medium academic preparation, an international social network, and a relatively limited connection to the country they grew up in. Which of these is “better” depends entirely on the family’s values and the child’s path. The bilingual outcome is not inferior. It’s different.

Objection four: “Foreign teachers won’t teach there.”

Reality: this is partly outdated. The major bilingual schools employ substantial numbers of foreign teachers. Sarasas Ektra has dedicated foreign teaching staff for English-medium subjects. SISB recruits internationally. BVIS uses the same Nord Anglia teacher pipeline as BIS, with the same standards.

What’s true is that the foreign teacher pay at bilingual schools is generally lower than at premium international schools. THB 60,000-90,000/month is typical at the top bilingual schools, vs THB 120,000-170,000 at the premium internationals. This affects who applies. The bilingual schools tend to attract teachers earlier in their international careers, those with strong values around bilingual education, or those who specifically want to teach in the local cultural context. The premium internationals attract teachers later in their careers with families to support and mortgages to service.

Whether your child’s specific teachers are excellent depends on the school, not the category. Bilingual schools have excellent teachers. International schools have mediocre teachers. The label doesn’t determine the outcome.

Who bilingual schools are best for

The honest case for bilingual schools is not “they’re cheaper and just as good.” It’s more nuanced.

Bilingual schools are particularly strong for families who:

  • Plan to stay in Asia long-term (10+ years), and want their children to be genuinely fluent in the local language as adults
  • Have one parent who is a national of the country (Thai-British, Vietnamese-British, etc) and want the children to be culturally bilingual
  • Are price-sensitive and willing to do the diligence required to choose a strong bilingual option
  • Value cultural immersion as part of the education
  • Are not planning to send children to UK universities at the elite end (Oxbridge level), where premium international school networks may have marginal advantages

Bilingual schools are less strong for families who:

  • Are on a short Asian assignment (3-5 years) and need easy integration in and out
  • Are committed to Oxbridge or Ivy League university outcomes where every margin matters
  • Have children with significant special educational needs (the support infrastructure at premium internationals is typically stronger)
  • Place high value on the social network and community continuity of expat international schools

The bilingual decision is most consequential for the middle-ground family: a British family planning 7-15 years in Asia, with children who are academically average to strong, where the £500,000+ saving over a school career meaningfully changes the family’s financial position.

For this family, the bilingual option is rarely seriously considered, and rarely seriously assessed, because the entire information environment around expat education in Asia is built by and for the premium international schools. Recruitment companies, relocation services, employer education advisors, expat parent forums, all default to the premium options. The bilingual middle ground requires a family to actively seek it out.

The honest comparison

Here’s the cleanest summary of the choice for a British family in Bangkok with two children, age 5 to 18:

Option13-year cost (2 children)What you get
Sarasas Ektra (bilingual, GAC)£180,000-£250,000Bilingual Thai-English, GAC for university entry, deep cultural integration
Wells International (bilingual-international hybrid)£280,000-£400,000Mostly English-medium, British-aligned, mid-tier facilities
BVIS Hanoi or SISB Bangkok (premium bilingual)£320,000-£450,000Cambridge IGCSE/A-Level, foreign teacher cohort, Western university progression
Bangkok Patana (non-profit international)£480,000-£580,000Full British curriculum, premium facilities, established expat community
Harrow/Shrewsbury (premium international)£620,000-£760,000Full British curriculum, prestige brand, premium facilities

The gap between Sarasas Ektra and Harrow Bangkok is roughly £500,000 over two children’s school careers. That £500,000, if invested in a UK ISA at 5% compound growth across the period it would otherwise be paid out, becomes roughly £750,000 by the time the children leave school.

This is the practical truth nobody discusses in expat WhatsApp groups. Choosing a quality bilingual school over a premium international school is worth somewhere between £500,000 and £1 million to a British family’s lifetime financial position.

What parents can actually do

The structural information disadvantage facing bilingual schools is real. The schools don’t have marketing budgets to match the internationals. Recruitment companies don’t push them. Employer relocation packages don’t list them. So the practical recommendations are:

Visit at least one bilingual school during your school search, even if you’re “definitely” going premium international. The visit gives you a calibration point that almost no other British family has.

Ask the bilingual school for their university destination list for the last three years. A strong bilingual school will share this proudly. A weak one will deflect. Use this as the single best filter.

Talk to current parents, ideally other Western expats. The information network around bilingual schools is much thinner than around the internationals, so finding current Western parents (often through Facebook groups, expat forums, or the schools themselves) is valuable.

Run the 13-year cost comparison explicitly. Most families don’t, because the schools don’t make it easy. The number is large enough to genuinely affect family planning.

Consider the bilingual option seriously for younger children even if you’ll move them to international later. Several families use bilingual primary schools (where language acquisition is strongest) and then transition to international secondary schools (where exam credentials matter most). The combined cost can be 30-40% lower than full international, with potentially better language outcomes.

The takeaway

The bilingual middle ground is the most underexplored education decision available to British expat families in Asia. It saves £300,000-£700,000 over a typical family’s school career compared to premium international options. It produces students who are genuinely bilingual, culturally integrated, and academically competitive for university entry. It does not produce the same expat social network or institutional prestige as the premium internationals.

For some families, the prestige and social network are worth the money. For most families, they probably aren’t, but the question is rarely asked properly.

The schools exist. Sarasas Ektra has been running since 1995. SISB has been in Bangkok since 2001. Vinschool has been growing across Vietnam for over a decade. BVIS, Olympia, and Wellspring are established. The information about them is just less visible because the premium international schools have better marketing.

If you are a British family in Bangkok, Hanoi, HCMC, or KL with school-age children, the single most valuable diligence step you can take is to spend a day visiting a strong bilingual school in your city before signing the next international school contract. The financial implications are large enough to genuinely justify the time.

In the next pieces in this pillar, we’ll look at the curriculum economics question (British vs American vs IB vs Australian, what each costs, what each unlocks), the demographic shift inside “international” schools that’s quietly changing who actually attends them, and where the fees actually go in those operating budgets.

The thread connecting all of these pieces is the same. The international school economy operates the way it does because most families don’t ask the structural questions. Once you do, the choices look different.