← Back to homeBase International School
Alcobendas, Spain · est. 1962 · Private
Illustration · Alcobendas
Base International School is a private, independent, non-denominational school in La Moraleja, a Madrid suburb in Alcobendas, running since 1962 and called Colegio Base until 2023. It traces itself back to the Institución Libre de Enseñanza and holds to that inheritance literally: critical thinking, intellectual freedom, horizontal relations with the teacher, classroom assemblies and structured debate from Primary onwards, and the UNESMUN model United Nations. Everything is on a single 31000 square metre campus, brought together in 2019 by buying the adjoining school, and the stages run from age one to eighteen. It is a medium-sized school and it states its own numbers: 710 pupils and 72 teachers, that is 9.9 pupils per teacher, more than thirty nationalities, a 94 per cent staff retention rate and an average teacher tenure of 12 years. Since 2024 the school has been part of Affinitas Education, a network of more than twenty schools. The main thing a parent needs to know: at the senior stage the choice between the Spanish Baccalaureate and the IB Diploma costs very different money - 1030 euros a month against 1300 - and the PYP at the junior stages is, by the programme page's own words, still going through authorisation.
Key facts
Tuition
≈ $5 536–14 692 a year
4 900–13 005 EUR
Languages of instruction
Spanish, English
Registration fee
≈ $678
600 EUR
About the fees The fee for 2025/26 is divided into ten monthly instalments from September to June; the second year of the baccalaureate, both Spanish and IB, into nine, from September to May. Preschool (ages 1 to 5): full-day 630 euros a month, morning-only 490 (that option exists only for the first cycle, that is for ages one and two). Primary school (ages 6 to 12): years one and two 800 euros, years three and four 820, years five and six 830. Secondary school, ESO (ages 12 to 16): years one and two 890 euros, years three and four 910. Baccalaureate (ages 16 to 18): year one of the Spanish route 1030 euros, year two 1145; year one of the IB Diploma Programme 1300 euros, year two 1445. The fee covers individual school supplies, all trips and activities within school hours, and extended hours from 7:30 to 9:00 and from 17:00 to 18:30, which are free at every stage. Separately: school lunch with an afternoon snack 245 euros a month (in the baccalaureate two days a week 125, snack only 45, a single-day lunch 20), transport 150 euros a month for one journey and 235 for two (in the baccalaureate 100 and 150, special zone 110 and 150). One-off and annual charges: a psychological assessment in designated year groups 100 euros, the annual medical check-up 68, school accident and health insurance 107, graduation photographs 25, the yearbook 50.
Admissions The school admits pupils all year round, from September to July, and an application can be made on the website. First the school checks whether there is a place in the requested class, and if there is, it asks for the child's latest marks from the previous school. Then it invites the family to the campus for a meeting of about an hour, shows the premises, introduces the team and works through how the fee applies to that particular family; an admissions officer helps with the documents. A separate person, the family coordinator, accompanies every new family throughout the year. The school takes foreigners: its pupils are of more than thirty nationalities. On its admissions pages the school names no separate conditions for children from abroad, such as recognition of previous marks or requirements in Spanish or English.
Stages and year groups Grades preschool from age 1 - baccalaureate, up to age 18. The stages are: preschool from 1 to 5 (the first cycle, ages one and two, has a morning-only option), primary school from 6 to 11-12, secondary school (ESO) from 12 to 15-16, and the baccalaureate from 16 to 18. The baccalaureate has two routes: Spanish and the IB Diploma Programme. The school runs the IB programmes thus: the MYP and the Diploma are authorised, while the PYP in preschool and primary is, by the programme page's own words, still going through authorisation.
Address Camino Ancho 10, La Moraleja
Accreditations and programmes verified against official registries
IB · MYP, DP · authorised programmeAffinitas Education · school is part of the networkschool is in an official registryconfirmed by a school document, by membership or by taking part in a networkclaimed by the school, no confirmation, not counted in the scoreGuide to all organisations → What stands behind each entry
IBInternational Baccalaureate
A Swiss non-profit, working since 1968. Its programmes are among the most widely recognised school programmes in the world. Authorisation is granted stage by stage, so a school with the final stage does not necessarily run the younger ones; which stages this school holds is set out in the line below.
What the badge means for this school. The school is allowed to run this programme and to award its certificate. This is a confirmation of the programme, not a judgement on the school as a whole. The entry stands in the organisation's public register - anyone can check it. At this school: MYP (ages 11-16), DP (ages 16-19). MYP is the middle stage, ages 11 to 16. There are no exams here either; at the end an optional electronic assessment of pupils' work is possible. DP is the final stage, ages 16 to 19: six subjects plus a compulsory core of theory of knowledge, an extended essay and CAS. The diploma is accepted by universities all over the world, and in a number of countries it counts for admission on the same footing as the local leaving certificate.
Register to check for yourself, and the full guide →Affinitas Educationschool network
Affinitas Education is an international group of private schools; its site gives neither a founding year nor an owner. The group gives different school counts on its own pages - "30 international schools" in the text, "30+" in a counter and 25 schools in the catalogue on the same page - and we quote all three: choosing for a group which of its own numbers is correct is not something we do. On the same page the group cites more than 20,000 students, 7 countries and 3 continents; its catalogue includes schools in Spain, Portugal, Italy, the United States, Mexico and Brazil. In Spain there are six schools: in Seville, Madrid, Málaga, Xàbia (Alicante province) and two in the province of Valencia. The group's site is affinitasedu.com.
What this means for this school. The network owns or operates the school. Its accreditation and programme authorisation the school obtains separately, in its own name.
Exams and destinations from the school's official website
Exam results The school publishes the results of the Spanish university entrance examination EvAU for 2024: 100 per cent passed, the average mark was 8.25 out of 10, the highest 13.475 out of 14. It does not publish IB Diploma results.
Facilities from the school's official website
✓Swimming pool
·Sports hallnot stated on the website
·Laboratoriesnot stated on the website
·Theatre or assembly hallnot stated on the website
·Librarynot stated on the website
✓Catering
✓School transport
·Boardingnot stated on the website
Also on site: Art studio
Campus: A single 31000 square metre campus in La Moraleja, brought together in 2019 by buying the adjoining school - before that the stages stood apart. Meals are prepared in the school's own on-site kitchen, with different options by year group and individual need; for 2025/26 the school is introducing two lunch sittings to free up time for extracurricular activities. There is a swimming school of its own with a pool, used by pupils and families alike. The art and music rooms have been completely rebuilt, and the school is seeking official accreditation as a music conservatoire. Bus routes run in several options depending on the stage and the number of journeys.
Clubs and activities (13): Swimming · Theatre in English · Music
Teaching staff from the school's official website
·Teachers listed by namenot published
·Teacher qualificationsnot stated
·Number of teachersthe school does not say
✓Students per teacher or class sizein the key facts above
The school states 72 teachers for 710 pupils, that is 9.9 pupils per teacher, and says this is more individual attention than UNESCO recommends. 94 per cent of teachers stay at the school, and the average tenure there is 12 years. The leadership team is published by name: the head of school, deputy heads for preschool, primary, secondary and the Spanish baccalaureate, the academic coordinator, the head of guidance who is also the designated safeguarding lead, and the family coordinator.
Safety and wellbeing from the school's official website
·CCTVnot stated on the website
·Security staffnot stated on the website
·Access controlnot stated on the website
·Nurse or medical roomnot stated on the website
✓Counsellor
✓Child protection policy
·Staff trainingnot stated on the website
·Anti-bullying policynot stated on the website
The school has its own team of educational psychologists and counsellors, a separate counselling and psychopedagogy department, and a named Designated Safeguarding Lead. For 2025/26 it announced a dedicated specialist safeguarding team with a preventive and structural approach that takes an active part in school-wide decisions. Safeguarding is also named as a shared priority of the Affinitas Education network the school belongs to.
Reviews
No reviews yet. The community rating counts towards the score once a school has five verified reviews - until then we do not show a zero, so as not to mislead.
Criteria breakdown criterion weight in brackets
Academics and programmes (16%)88 Community rating (16%)no dataparent reviews are needed: the criterion switches on at the fifth verified one Exams and destinations (12%) scored on disclosed data80 Safety and wellbeing (12%) scored on disclosed data65 Accreditation and verifiability (10%)85 Teaching staff (10%) scored on disclosed data55 Facilities (10%) scored on disclosed data75 Clubs and activities (8%) scored on disclosed data67 "Scored on disclosed data" stands where we count only what the school has written about itself on its own site: exams and destinations, safety and wellbeing, teaching staff, facilities, clubs and activities. A low score here means the school does not write about this, not that the school does not have it: a school with good security and a sparse site will score low. A school can fill in its profile, and the score will be counted again.
The score is counted from 8 of the 9 criteria.Only those with checkable data count: programmes and accreditations from official registers, the fee from a published price list. Where it says "scored on the median", the school has no data and the middle of the list is put in its place, so that a gap gives no advantage. Admissions, teaching staff and reviews come in as their data arrives.
The full methodology → Similar schools in the country