There are 6,717 International Schools worldwide with a total of 3.4 million pupils, up 7.7 per cent in the past year. Many offer the International Baccalaureate, or IB, a rigorous academic qualification that is common currency for entry to British and American universities, and annual fees in Europe are typically £7,500 to £14,500.
"Remote working and new technologies mean more people are moving abroad and often the choice of where to settle is driven by the availability of high-standard education," said Alex Upson of Cluttons Resorts.
With its polo fields, tennis courts, world-class golf courses and modern marina, the gated 4,500-acre estate of Sotogrande in Andalucía is a magnet for sporty families, and Sotogrande International School is clearly part of the appeal.
The opening of the border with Gibraltar 20 minutes away and the expansion of the financial sector in the former British colony helped fuel the school's growth. More than 650 children aged three to 18 from 68 countries are taught at Spain's only IB boarding school with elite academies for golf and tennis.
Property in Sotogrande starts from £106,500 for a resale flat in the port through Savills, while new two-bedroom flats at Ribera del Marlin with indoor and outdoor pools, gymnasium and underground parking start from £300,000 through Cluttons Resorts.
* Cluttons Resorts: cluttonsresorts.com (020 7584 3050)
* Savills: savills.co.uk/abroad (020 7016 3740)
* Sotogrande International School: sis.ac/welcome
There are 30 nationalities among the 470 pupils at the International School of Florence, the only school in Tuscany to offer the IB. Children aged three to 18 are split between two renaissance villas — the junior school six miles outside the city at Bagno a Ripoli, and the upper school in the centre. Class sizes are maximum 16.
Lessons are in English and 98 per cent of students sit the IB. However, an Italian programme is woven through the curriculum and students can choose to sit Italian public exams too. "Most parents choose the school first and then decide where to live," said Tanya Bruckner, International School of Florence marketing director.
Across the River Arno from the school, steps from the Piazza Duomo, Cluttons Italy has a two-bedroom flat with exceptional roof terrace reduced from £1,520,000 to £1,266,000. A three-bedroom restored apartment in Piazza della Signoria is newly reduced to £582,800 through Knight Frank.
* Knight Frank: knightfrank.com (020 7629 8171)
* Cluttons Italy: cluttonsitaly.com (00 39 075 845 0100)
* International School of Florence: isfitaly.org
MOUGINS AND NICE, FRANCE
International schools in the South of France include the ones in Mougins, which follows a British curriculum, and Nice, with a full IB programme.
"Access to a good-quality international school is really important for the many foreign buyers around Aix-en-Provence," said Rudi Janssens from Knight Frank associates Janssens Immobilier.
Small flats in Aix start from £422,000 with two- and three-bedroom homes in new developments around La Rotunde, the town's main fountain, from £591,000. Three- and four-bedroom detached homes 30 minutes' drive from Aix in popular villages such as St Cannat and Saint-Marc-Jaumegarde cost from £1,266,000.
* Knight Frank: as above
* Chesterton Humberts: chestertonhumberts.com (020 7201 2071)
* For discussion forums and further advice: angloINFO.com
Tracey and Simon Farmer are relocating from Gozo, Malta to the South of France so that their daughter Wendy, five, can attend Nice International School from January next year. It's an upheaval they believe is worth any short-term hassle to give Wendy a secular, international education.
"Simon is a super-yacht captain so there are a number of places worldwide where we could live," said Tracey. "We decided on an international school over an English boarding school because we see the value of the International Baccalaureate and being educated in an international environment."
Tracey's advice is to research an International School's reputation, think carefully about its size, and then consider connectivity. Nice airport provides rapid access throughout Europe.
"As with any school one size doesn't fit all," she said. "I wanted Wendy to be in a fully accredited IB programme from the very beginning of her school life."
* International School of Nice: (isn-nice.com).