One of the most frequently asked questions we receive is simple and completely logical:

The cost depends on many factors – technical, construction and operational.

What is the Price Per Square Meter?

In the Greek market, indicatively:

• Extensive green roof: from ~80€ to 140€/m²
• Semi-intensive system: from ~120€ to 200€/m²
• Intensive green roof / roof garden: from ~180€ to 350€/m² and above

These prices are indicative and vary depending on:

• the depth of the substrate
• the planting (low vegetation or trees)
• the irrigation systems
• the accessibility of the construction site
• the special structures (deck, seating areas, pergolas, etc.)

What Affects the Cost?

1. The Static Adequacy of the Building

The first and most important element is whether the building can accept the load of a green roof.

The saturated weight of a system can range from:

• 120–150 kg/m² (extensive)
• 300–600+ kg/m² (intensive)

If reinforcements are required, this increases the total cost.

2. System Quality

Not all systems are the same.

The use of certified systems, such as those from Optigreen, ensures:

• proper drainage
• waterproofing protection
• controlled water retention
• long-term durability

The quality of the infrastructure directly affects the cost — but mainly the lifespan.

3. The Growth Substrate

The substrate is not just soil.

A special mixture of lightweight materials and organic matter is used, such as

ERSM – Ecoverti Roof Substrate Mix, which is designed for proper drainage, ventilation and reduced weight.

The quality of the substrate affects:

• system stability
• plant nutrition
• long-term performance

4. Irrigation & Fertilization

A modern green roof usually includes:

• automatic irrigation system
• humidity sensors
• remote control
• fertigation

“Smart” systems slightly increase the initial cost, but significantly reduce operating costs.

5. The End Use

Another cost is a:

• bioclimatic low-planted roof
• and another a roof garden with seating, lighting and trees

When the space is intended for use (hotel, bar, residence), the design becomes more complex.

How much does it pay?

A properly designed green roof:

• reduces energy consumption
• increases commercial value of a property
• protects waterproofing
• creates usable space
• enhances ESG and environmental footprint

In commercial properties, payback can come within a few years through increased revenue or reduced operating costs.

When Does Cost Increase?

• When there is no proper study
• When non-certified materials are used
• When drainage is omitted
• When an inappropriate substrate is installed

Mistakes cost much more than the initial investment.

Conclusion

The cost of a green roof in Greece starts from relatively affordable levels and is formed depending on the use, technology and requirements of the project.

But the essence is one:

A green roof is not a decorative addition. It is a technical system of long-term value.

When designed correctly — with proper stratigraphy, certified systems, and technical precision — it is an investment, not a cost.