A Greek island Passivhaus
21°s Communications Manager Chayley Collis discovers more about the Passive House Paros project, while on a family interrailing holiday to Greece.
The Passivhaus community definitely exists outside of twitter in the enthusiasm of its adherents throughout the world. As a philhellene and Passivhaus enthusiast I was therefore delighted to meet the owners of the Passive House Paros project while travelling in Greece. The project is the third Passivhaus to be built in Greece and is the first to be built on a Greek island, as far as the team are aware. The clients have the same enthusiasm and pioneering spirit as our own wonderful clients at Denby Dale and the same generosity in sharing the story through blogs and PR. As at the outset of Denby Dale, there are a lot of unknowns and uncertainties: will it get through planning requirements, will they be able to work with the north facing site, will a local building company be able to work to the exacting requirements of Passivhaus; will it work?
Passivhaus in the Mediterranean
I was really interested to find out how the Passivhaus methodology can be applied in a hot temperate climate. Apparently the insulation in the walls (external insulation with rendered white wall) will need to be less than for a northern climate. Extra opening windows are also needed for ‘Mediterranean purging’ to help purge the house of heat at night and ensure the house stays cool. The thermal mass of the building will help deliver cool in the way that in the UK it delivers heat. Planting deciduous plants and shading strategies will be crucial. I also learnt about something called bioclimatic architecture which, in addition to Passivhaus, will help the design team develop the layout of the house. It involves taking into account wind speeds and climate to best optimise comfort. The site for the house is on quite an exposed hillside which will be subject to high winds in the winter.
Design challenges
The preliminary designs for the house look really interesting – with a – typically Greek – central courtyard, making it a little different from the ‘classic’ Passivhaus box! The project is still at the very early design and discussion phases and has yet to be modelled in PHPP but is already throwing up challenges. The precipitous hillside setting requires the space to be divided into two sections – will they need two MVHR systems? Also Greek planning regulations make stipulations that there cannot be a straight unbroken wall of greater than 10m in length, which is creating some extra design challenges. Lastly the north facing aspect is not textbook Passivhaus ..but somehow I don’t think there’ll be any shortage of passive solar gain..
We also discussed the importance of a good ducting system for MVHR – something our MVHR department is always banging on about. But.. would spiral bound steel work in a Mediterranean environment or would it conduct too much heat? I will need to check with Andrew about that…
Despite the difficult economic situation in Greece, there is still an active self-build market, particularly on the islands, so the Passive House Paros will have a great relevance and will act as a template for other island passive houses. I wish the blossoming Greek Passivhaus movement kali tyxi- the very best of luck!
Links & contacts
Project website & blog: www.passivehouseparos.com
Architects: Athanasia Roditi (www.architect-lab.com)
Structural engineers: Stefan Pallantzas (www.passive.gr), Dr.Ioannis Pappas (www.green-evolution.eu)
