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-medium parallel stream a dealbreaker?

St Andrew's is the only school in this directory — and the only school in Thailand in our verified record — with a full Dutch-medium parallel stream from Reception through secondary, including IGCSE Dutch and IBDP Dutch at exam years. For Dutch-nationality or half-Dutch families, this is often the deciding factor regardless of curriculum comparison. ISE does not offer Dutch-medium instruction. If Dutch instruction is non-negotiable, 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 approximate 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 approximate bands (~฿270K–650K/yr) plus one-time fees — exact per-year amounts require the 2025/26 PDF from admissions. 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 (~150 students, 8:1 ratio, 50+ nationalities) 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 Gold accreditation — 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 (~150 students) 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; a Dutch-medium parallel stream matters; Forest School and eco-literacy ethos suit your child; Cognita network transfers are part of your planning; you accept approximate fee bands and will download the 2025/26 PDF; and lower entry-year approximate fees (~฿270K Nursery 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.