Skip to Navigation Skip to Content

Video & Project of the Week for June 15, 2015: The Hellenic Treasury – Constitution Square

on June 16, 2015 at 3:17 pm under Project of the Week: 6/15/15

The Hellenic Treasury – Constitution Square
Athens, Greece
6,997 sf. Greenroof


Project Description & Details

Considered the most important square of modern Athens from both a historical and social point of view, Syntagma (Constitution) Square is at the epicentre of commercial activity and Greek politics, situated opposite the Greek Parliament. The Greek Ministry of Finance installed a lightweight green roof, or “oikostegi,” within a shallow substrate depth (less than 10 cm) on the Treasury in Constitution Square with the main motivation being to provide a research roof to study the thermodynamic impact of a green roof in hot Athens. Designed and installed by Oikosteges, or OS Green Roofs, mainly indigenous Hellenic aromatic herbs were selected to be able to survive the harsh conditions such as several species of thyme, sage, lavender, mint, and oregano, among others.

Studies of the thermodynamics of the roof in September 2008 concluded that the thermal performance of the building was significantly affected by the installation. In further studies in August 2009, energy savings of 50% were observed for air conditioning in the floor directly below the installation. Energy savings totaling €5,630 per annum were recorded, which translates to a 9% saving in air conditioning and a 4% saving in heating bills for the whole building. The study also stated that while measurements were being made by thermal cameras, a plethora of birds and beneficial insects were observed on the roof, ranging from robin redbreasts, yellow hammers, yellow tits, coal tits, and sparrows to kestrels hovering high above eyeing up the smaller birds. Also, many species of pollinators have been seen such as honey bees, tiger swallowtail and monarch butterflies – plus dragonflies and ladybugs. The study suggested that both the micro-climate and biodiversity of Constitution Square had been improved by the oikostegi.

Find more photos and additional information about this project in The International Greenroof & Greenwall Projects Database.

The Hellenic Treasury – Constitution Square is’s Project of the Week in honor of its designer, Andrew Clements, who along with Karla Dakin was one of our esteemed speakers at our Greenroofs & Walls of the World Virtual Summit 2015. Their collaborative video “Two Extremes in Waterwise Design from Denver, Colorado and Athens, Greece” included The Hellenic Treasury.

Once again, thank you to all who supported us and contributed to this biennial online event!


Year: 2008
Owner: The Hellenic Treasury
Location: Athens, Greece
Building Type: Municipal/Government
Type: Extensive, Test/Research
System: Single Source Provider
Size: 6,997 sq. ft.
Slope: 1%
Access: Accessible, Private

Designers/Manufacturers of Record:

Greenroof System: Oikosteges 1 (OS1)
Greenroof Design & Installation: Andrew Clements, OS Green Roofs


Project of the Week Video Feature

Watch The Hellenic Treasury – Constitution Square Project of the Week Video below or see it on our GreenroofsTV channel on YouTube:

Did we miss your contribution? Please let us know to add you to the profile.

Would you like one of your projects to be featured? We have to have a profile first! Submit Your Project Profile.

Love the Earth, Plant a Roof!

~ Linda V.