In Lebanese real estate and zoning terminology, the investment ratio 25/50 usually refers to building regulations (zoning coefficients), specifically:
25% = Surface Occupation Ratio (نسبة الاستثمار السطحي / نسبة إشغال الأرض)
This is the maximum percentage of the land footprint that can be covered by the building at ground level.
50% = Total Exploitation Ratio (عامل الاستثمار العام)
This is the maximum total built-up area allowed across all floors (subject to municipal/zoning rules, setbacks, roof rules, basements, technical exemptions, etc.).
Example: Land in Mount Lebanon = 1,000 sqm
1) Ground Coverage (25%)
Formula:
1000 \times 25\% = 250 \, sqm
Meaning:
Maximum building footprint on the ground floor = 250 sqm
So, your building can occupy only 250 sqm of the land surface.
Remaining open land:
1000 – 250 = 750 \, sqm
This remaining area is generally used for:
setbacks
garden
parking access
swimming pool (if allowed)
terraces landscaping
2) Total Buildable Area (50%)
Formula:
1000 \times 50\% = 500 \, sqm
Meaning:
Total allowable construction area = 500 sqm
This is the total above-ground buildable area (depending on municipality and exclusions).
How Floors Work
Since total allowed = 500 sqm and ground footprint max = 250 sqm
Possible scenarios:
Scenario A — 2 Floors
Ground floor = 250 sqm
First floor = 250 sqm
Total:
250 + 250 = 500 sqm
This fully uses the permitted ratio.
Scenario B — 3 Floors
Example:
Ground floor = 170 sqm
First floor = 170 sqm
Second floor = 160 sqm
Total:
170 + 170 + 160 = 500 sqm
Still legal if setbacks and municipality rules permit.
Scenario C — Luxury Villa
Example:
Main villa = 400 sqm
Guest annex = 100 sqm
Total:
400 + 100 = 500 sqm. Possible, depending on the parcel’s shape and regulations.
Important Lebanese Practical Notes
In Lebanon, actual permitted construction may vary because municipalities may apply:
zoning classification (Zone A, B, C, etc.)
setbacks from neighboring boundaries
road setback requirements
roof/penthouse rules
technical room exemptions
parking requirements
basement treatment (sometimes not fully counted)
water tank/generator room exceptions
Solar infrastructure allowances
So, 25/50 is the base zoning ratio, not always the final exact buildable outcome.
Quick Investor Interpretation
For a 1,000 sqm mountain plot:
If construction cost = $700/sqm
Buildable area:
500 sqm
Estimated construction cost:
500 \times 700 = 350,000 USD
If finished sale value in Mount Lebanon = $1,500/sqm
Gross sale value:
500 \times 1500 = 750,000 USD
Indicative gross margin:
750,000 – 350,000 = 400,000 USD
Before:
land cost
permits
engineering
infrastructure
legal fees
financing
marketing brokerage
Simple Summary
For 1,000 sqm land with 25/50 ratio:
Ground footprint → 250 sqm
Total construction → 500 sqm Open land remains → 750 sqm