Archived research v1. Preserved for reference; its assumptions have not been revalidated for the new research.
The original study
8 · Sources & methodology
Edition dated 7 September 2026
💡 Where the figures come from, how they were constructed and the errors corrected along the way.
Strategic revision of 7 September 2026
The vision adds a network of full and compact clubs, followed by hotels centered on wellness and recovery. These are strategic directions and assumptions, with no openings or traction announced.
The financial review uses the exported parameters. It calculates collected revenue and a conditional margin sensitivity. It does not constitute an audit of the Excel workbook, which is absent from the published dossier.
Primary sources consulted for this revision:
- Villa M Marseille: club offer: €109/month, €500 joining fee, twelve-month commitment, classes and spa.
- SIRO One Za’abeel: positioning: fitness, recovery, sleep and nutrition at the heart of the stay.
- Soho House: 2024 results, published on 31 March 2025: House contribution margin of 26%; group adjusted EBITDA of $131.9m on $1,203.8m of revenue, or around 11%. The scopes differ.
- Accor: 2025 results, published on 19 February 2026: management and franchise model, used as a structural reference.
The Territories, Assumptions and Checks databases retain the original study's data; their inclusion does not constitute validation. The updated limitations in the chapters must accompany any use of these figures.
Introduction sources: underlying trends
Additional research on 7 September 2026. The figures describe their surveyed populations; they measure neither local demand at the target price nor the margins of a social club.
- Social club offers: Remedy Place, Othership and Rune. Official websites consulted for locations and services. These examples establish that the format exists, without constituting a global census or dating a wave of Paris openings.
- Fitness membership in Europe: Basic-Fit, Annual Report 2025, p. 16, citing EuropeActive / Deloitte, European Health & Fitness Market Report 2025, p. 111. 2024 data, rounded national rates: France ≈ 10%, Spain ≈ 13%, Netherlands ≈ 19%. The summary page does not detail the denominator's age ranges; do not treat the US comparison as a harmonized measure.
- US membership: HFA, 2024 data and HFA, 2025 data. Annual survey of around 18,000 residents aged 6 and over. Members are distinct from occasional users without a membership. Rates: 24.9% in 2024, 26.1% in 2025; 35.5% among 18–24-year-olds in 2025.
- Motivations and participation in France: INJEP / CRÉDOC, National Sports Participation Barometer 2025, especially p. 53. Quota survey of 4,010 residents aged 15 and over, in metropolitan France and the five overseas departments and regions, from 30 June to 15 July 2025. Motivations concern people who participated in the previous twelve months; regular participation means at least 52 sessions per year and covers more than gym-based fitness.
- Generations: ABC Fitness, Mid-Year 2026 report, data from 1 January to 31 May 2026. Gen Z: 46% of new gym members; millennials: 32%. Proprietary data, not representative of a national population. The press release does not specify the subset's exact geography. A share of new memberships does not prove a higher visit frequency. Scope of the ABC ecosystem.
- Loneliness in France: Fondation de France / CRÉDOC, Solitudes 2025, published in January 2026, survey conducted in July 2025 among people aged 15 and over. Feeling lonely “every day or almost every day” or “often”: 24%; 28% in cities with more than 100,000 residents, 21% in rural areas. This prevalence level alone does not measure an increase.
- Changes in social connections: OECD, Social Connections and Loneliness in OECD Countries, 2025, chapter 4, figures 4.5 and 4.10. Daily meetings with friends among 16–24-year-olds: 44% in 2015, then 36% in 2022, an average across 21 European countries. Loneliness most or all of the time over the previous four weeks: +1 percentage point among young people between 2018 and 2022 in 22 European countries; no statistically significant increase in the average across all ages. The wording and scope differ from the French survey.
Data sources
Demographics and income
- INSEE RP 2023: population by occupational category, by place of residence and workplace. The model's reference count is by place of residence.
- INSEE Filosofi 2023: median standard of living by municipality. Used for the affordability ratio (price / standard of living).
- INSEE MOBPRO 2022 (detailed file): commuting flows by occupational category. Used to calculate the outflow to Paris from Île-de-France catchments.
- INSEE ARM 2023: occupational categories by municipal arrondissement. Published, contrary to my initial assumption: managers and professionals account for 42.3% in Marseille's 6th arrondissement, 37.6% in the 7th and 38.9% in the 8th.
Comparables and market
- Official La Montgolfière pages (Canal, Lamarck) for floor areas, equipment, prices and services.
- Local broker listings for commercial / light-industrial premises and office rents.
- Price surveys of premium and wellness clubs in Marseille and Paris.
Processing pipeline
- Build a database outside Île-de-France: 42 municipalities × 25 indicators.
- Build an Île-de-France database: 61 rows (EPTs, EPCIs, municipalities) with actual counts of managers and professionals and commuting flows by occupational category.
- The original notes describe a Python P&L model, exported to an Excel workbook with 6 tabs and 189 formulas and reported as recalculated without errors. Because this workbook is not attached to the published dossier, that check could not be reproduced during the 7 September revision.
Errors made and corrected
They are listed here because they show where the model was most fragile.
| Error | Correction | Impact |
|---|---|---|
| Marseille missing from the ranking (grouped into “Aix-Marseille”) | Three geographic levels added: metropolitan area, municipality, southern triangle | Marseille becomes a candidate again |
| Marseille managers and professionals counted by workplace (90,532) | Count by place of residence: 79,635 (23.8%) | Catchment revised downward |
| Southern triangle estimated (~23,000 managers and professionals, 897/km²) | Actual ARM data: 26,617 managers and professionals, 1,006/km² | Catchment revised upward |
| Coworking attributed to Canal (Paris 10th arrondissement) | It belongs to Lamarck (Paris 18th arrondissement) | Thesis fully rewritten |
| Canal assumed to have 2,000 m² and a full equipment set | 1,700 m², 14 Technogym machines | Maximum rent: €385 → €571/m²/year |
| Paris suburbs missing from the ranking | 22 Île-de-France catchments added | Three serious new candidates |
What has not been verified
- La Montgolfière membership numbers (~1,200) are a public estimate, not confirmed by the operator.
- Rents in southern Marseille (€90–150/m²/year) come from listings, not signed leases.
- No actual fit-out quote has been obtained.
Related documents
The Claude project “New start” contains the detailed working notes: Marseille market assessment, TAM for second-tier cities, Paris suburbs demographic database, La Montgolfière reverse engineering, mini business plan, southern Marseille rents and coworking, blind spot audit, validation protocol and field interview kit. Research window: 1–3 September 2026.