Manage the 49% foreign-quota constraint on condos

The rule, in plain English

Thailand's Condominium Act B.E. 2522 (1979), Section 19 caps foreign ownership of any condominium project at 49% of the total saleable area. Once a building hits that ceiling, you cannot register a new foreign-buyer transfer at the Land Office, period.

The 49% is calculated on area, not unit count. So 49 small studio units owned by foreigners + 51 large penthouses owned by Thais could put a building at 30% foreign by area while looking 49% foreign by unit count. Always check by area.

How DevProp tracks it

When you create a Building entity (Settings → Buildings → New), you set five quota-relevant fields:

1. total_saleable_sqm — sum of all condo unit floor areas (excludes common areas, parking, mechanical floors).
2. foreign_owned_sqm — area currently owned by foreigners. Update from the building's juristic-person register.
3. foreign_owned_pct — auto-calculated = foreign_owned_sqm / total_saleable_sqm × 100.
4. foreign_eligible — auto-calculated = (foreign_owned_pct < 49%).
5. last_verified — timestamp of when you last updated the foreign-owned figures.

Each listing in that building inherits foreign_eligible. When the building flips to ineligible, every unsold listing in it flips simultaneously.

When the quota changes

Three events update the quota automatically:

1. A foreign buyer closes — the unit's area is added to foreign_owned_sqm. If the new % crosses 49%, the building flips to ineligible.
2. A Thai buyer closes on a foreign-held unit (resale) — the area is subtracted from foreign_owned_sqm. If the % drops below 49%, the building flips back to eligible.
3. You import an updated juristic-person register (Settings → Buildings → Bulk update from CSV). This is the recommended monthly hygiene step for high-velocity buildings.

Every change is logged with timestamp + actor + transaction reference for PDPA audit and dispute resolution.

Workflow: a foreign buyer enquires

A Chinese buyer messages your LINE OA: "I'm looking for a 1-bed condo in Sukhumvit around 8 MB."

1. Agent filters inventory: price 6-10M, type condo, location Sukhumvit, foreign_eligible=true.
2. DevProp returns only units in buildings under 49% foreign quota. Buildings at or above 49% are hidden.
3. Agent shares 3-5 units via LINE. Each link goes to the public-website unit page (in Mandarin if available).
4. Buyer picks one → reservation triggered. DevProp pre-checks: "This will move the building from 47.2% to 49.6% foreign. Continue?" Agent confirms with buyer + records the transaction.
5. On Land Office transfer day, the actual area is logged. The quota auto-updates.

Reporting: which buildings are close to the cap?

Reports → Foreign quota → "At-risk buildings". This dashboard shows every building where:

1. Current % is 45-49% (close to cap, careful with new foreign reservations)
2. Pending foreign reservations + current % would push over 49% (block)
3. Last quota update is > 90 days old (recommend refresh from juristic register)

For developer-direct agencies, this dashboard is your master view: it tells you, for each new project, when to start prioritizing Thai-buyer marketing to keep room for premium foreign-buyer deals.

What if I don't have accurate foreign-quota data?

Most agencies don't, especially when they're starting with DevProp. You have three paths:

1. Set to unknown — the building stays in foreign_eligible=null state. The CRM warns the agent before any foreign-buyer reservation: "Foreign quota unknown for this building. Verify before committing."
2. Ask the developer / building manager — they have the register. Pay them 500-2,000 baht and get the update.
3. Conservative estimate — assume 35% foreign for any new launch, 40% for buildings 5-10 years old, 45% for buildings 10+ years old. This errs on the side of caution but lets you keep operating.