ISE vs St Andrew's.

Five questions.
Five answers.

1. Do you want IB Diploma on American AERO/NGSS — or on British IB PYP + IGCSE?

This is the structural fork between these two IB Diploma day schools. ISE runs American AERO + NGSS from primary through IB Diploma — MAP, PSAT, and SAT integration built into the American track, with an American high-school diploma available at G11–12 alongside IBDP. St Andrew's runs IB Primary Years alongside British National Curriculum from primary — your child enters the IB framework before secondary, then IGCSE, then IB Diploma only at Sixth Form. If US-university planning, American transcript portability, or NGSS science standards matter, ISE is the only school in this directory with a full American-through-IB pathway. If you want IB philosophy embedded from early years on a British foundation, St Andrew's offers structural PYP continuity Garden and ISE do not.

2. Is a Dutch language programme a dealbreaker?

St Andrew's publishes three to six hours per week of Dutch language and culture lessons from Reception through secondary, with CNaVT and IBDP Dutch routes. The school calls it the Eastern Seaboard's only Dutch Stream; it is not a full Dutch-medium parallel curriculum. ISE does not publish comparable Dutch instruction. If sustained mother-tongue Dutch matters, St Andrew's is the structural fit. If your family is English-medium only, move to commute and fee calculus.

3. Sriracha commute or Rayong commute — where does your family live?

ISE at Bowin, Sriracha sits ~35 minutes east of central Pattaya — structurally closer for families in Sriracha, Laem Chabang, or the Bowin industrial corridor. St Andrew's at Banchang, Rayong sits ~30 minutes south — often smoother for families already in Rayong or Ban Chang. Neither is a Pattaya-side school. Test both commutes at school-run times before enrolling. If you live east of Pattaya, ISE wins logistics; if you anchor south toward Rayong or U-Tapao, St Andrew's may edge the daily run.

4. Can you budget ISE exact tuition-only vs St Andrew's published fee band?

ISE gives exact published tuition-only numbers: ฿358K (Pre-K) → ฿514K (K–G5) → ฿601K (G6–8) → ฿617K (G9–10) → ฿646K (G11–12 IBDP). Add lunch, bus, and exam fees for all-in. St Andrew's publishes published fee bands (฿213K–868K/yr) plus one-time fees — exact per-year amounts require the 2026/27 PDF from the school. St Andrew's is lower at entry and at Year 1 peer comparison; ISE's exact structure suits families who model budgets in spreadsheets. Neither is a budget-tier option — both sit in Established-to-premium IB territory.

5. WASC small-cohort intimacy — or Cognita forest-school scale?

ISE runs a deliberately small campus (a published student-to-teacher ratio below 8:1, with current enrolment not published) inside Burapha Golf Club — intimacy, WASC credentials, and first IBDP in the region (2003) over regional sports circuits. St Andrew's runs a 30-rai Cognita campus (~450 students) with Forest School outdoor pedagogy, eco-literacy projects, and EDT Silver rating — larger campus culture with network portability. Test both campuses with your child. The right fit is often temperament — small American-track cohort versus ecology-curious outdoors child on a larger IB PYP campus — not headline fee bands alone.

Summary verdict

• Choose ISE if: American AERO/NGSS through IB Diploma fits your plan; WASC accreditation and a deliberately small cohort (current enrolment not published) matter; you live east of Pattaya (Sriracha, Bowin, Laem Chabang); MAP, PSAT, SAT integration fits US-university planning; and American diploma optionality at G11–12 is valuable insurance alongside IBDP.
• Choose St Andrew's Green Valley if: IB Primary Years + Diploma with British IGCSE foundation fits your plan; Dutch language and culture lessons matter; Forest School and eco-literacy ethos suit your child; Cognita network transfers are part of your planning; you accept published fee bands and will download the 2026/27 PDF; and lower entry-year published fees (฿213K Nursery 3 half-day vs ISE ฿358K) matter for your budget.

Neither fits — if…

You need Pattaya-side premium IB with boarding — see St Andrew's vs Regents. You want Rayong British IB without American overlap — see Garden vs St Andrew's. You want American + IB at lower fees in Nongprue — see ISE vs MIS. You need pure British A-Level without IB — see Rugby vs St Andrew's.

Make the IB comparison child-specific

Ask both schools for the current IB Diploma subject list, prerequisites, timetable blocks, counselling sequence, examination charges and recent cohort context. ISE’s IB route sits alongside an American high-school diploma; St Andrew’s follows British and IB PYP foundations toward IGCSE and the Diploma. The shared IB endpoint does not make the preceding education or fallback route identical.

For a younger pupil, compare the classroom they will enter rather than the qualification they may take years later. At ISE, observe how AERO and NGSS expectations appear in teaching and ask for the actual class size. At St Andrew’s, ask how British curriculum and PYP work together, and observe Forest School or outdoor learning only if it is part of the proposed class’s normal timetable.

Use complete invoices and real routes

Start with standard 2026/27 tuition, then add application, registration or enrolment, refundable deposits, meals, transport, books, uniform, trips, examinations and assessed support. Keep payment discounts separately labelled. ISE’s tuition excludes lunch, bus, uniform and IB examinations; St Andrew’s family should request the exact year-group row and all compulsory extras from its current schedule.

Run both journeys during school traffic and obtain exact bus quotes to the home address. Record pickup times and late-activity returns beside the invoice. The defensible choice is the package whose present classroom, full annual cost, IB subject route and weekly commute all work for this child—not simply the school whose curriculum label sounds more familiar.