Passivhaus Basics Seminar
I spent the past Saturday attending a seminar by the Hellenic Institute of Passive House. The institute is affiliated by the International Passive House Association, whose main slogan is "Think globally, act locally".
This was the best way to kick-start an day-long discussion about the effects of adopting the manufacturing and construction of passive houses in Cyprus. Among the audience, students, architects, consultants, mechanical and civil engineers expressed their constant concerns to the main and guest speakers.
Because truly, Passivhaus is a German-born idea. Thus it is adapted to German climate and conditions which merely resemble the ones of Mediterranean islands such as Cyprus, which with the passing of time and our mere concern about climate change, it recently reminds of tropical weather to the locals. Humid rain during summer periods and heavy heavy sunlight for the most of the day. This brought us about to the fact that exactly Passivhaus is just a vernacular architecture turned greener according to our modern technological needs and discoveries. Renewable energies sustain the house's minimal needs that are not covered by choice of material, construction, and design. Only in Cyprus the greatest need is shading and coverage; shading and coverage of the periphery of the house, just like a bracelet surrounding all openings from direct sunlight entering the house. Parapets; only if we look them further into Cypriot vernacular architecture or actually more warm climates such as India in further extends we realise that this is the way the locals have assigned their standards of housing for effectiveness and efficiency of living conditions.
Arched peripheries make the veranda/balcony pergolas that brace the walls of the house. This is one of the cultural beauties that have lasted until these days and can appear from precolonial, to colonial and post colonial architecture.
Personally, I find the vernacular as an architect's absolute basis to follow for gathering designs. It is the most important factor. And through passive house, this is what we are supposed to follow. In my post I am going to refer to some examples of passive houses not necessarily mentioned in the seminar I attended but due to personal experience with the buildings. Furthermore, the seminar has concluded to material and technique decisions to avoid thermal bridging, reinforce air-tightness, while acting in accordance to all site elements.
Highlighting the seminar was analysis of most structures available by Cypriot suppliers as well as Austrian and German where there appeared to be a complaint and request by the local consultants that the locals should provide more suited material and important masonry that appear vital for thermal efficiency however pricey to import.
Thermal comfort was then another great discussion. Everyone in the audience speaking as a local who has lived the climatic conditions of the island both winter and summer, we concluded that in contrast to German Passive Houses, where the necessities for thermal comfort is heating, in Cyprus we have to focus on cooling. Whilst the construction of how I know it in Austria, buildings are constructed in excellent thermal efficiency, and sometimes electric heaters are rarely needed during the winter. The sunlight in the student residence where I have stayed in Graz, Austria for 6 months was used through excellent design to absorb it in sufficient quantities. Of course, being a palace previously and having been refurbished only recently it was the best sample of a dormitory to taste the Austrian architecture notions of these days.
Neutorgasse 47 was actually the second of my options. My first option for dormitory was Moserhofgasse. This one was a passive house. And being a first year architecture student going to second year this was exciting news. Neutorgasse of course is not a passive house. Therefore I had more options of criticising the design into action. During sunny warm days the low rays of the sun used to hit the roof built rooms whose windows were tilted with an obvious purpose. To let in natural lighting for the residents (which I so highly applaud, being a student in a university of England and being so badly denied of the right of sunlight in my room) and heating better the room. However as discussed in our seminar in a quick conversation, this might have been an honest mistake of the designers. Although I should mention that this is a student dormitory thus no one is probably staying there during the three months of summer which should be the hardest. Bad those winter mornings were completely taking advantage of this site analysis that came as a vital part before the design. I would certainly go back to Austria, having appreciated all their architectural sensitivities.
Affordability of passive houses was another topic of discussion as the speakers were trying to show us how the initial cost will certainly overcome the functional cost.
Natural ventilation, shading and lighting lead back to the ways of traditional, bio-climatic architecture. This is a fruitful orientation of design. However, the ways that passivhaus is directed through technology includes triple-glazing, low U-values of 0,8 depending on the country, minimal thermal bridges with ventilation of 0,6/h. Also it is important that we design spaces that do not have a big change of temperature near windows and near the nucleus of the building. In the seminar we also examined thermoplastics. We know that plastic's enemy is definitely the sun, especially in Cyprus. The German passive house has opposite bioclimatic situations than countries in the Mediterranean. Therefore for windows and openings we should use opposite values such as a low 'e' for inside spaces and solar 'e' for outdoors. We also spoke about the use of expanded polystyrene with graphite, in contrast to extruded which has some limitations in construction. This can be used for further improvement of indoor air humidity, as air change rate can be reduced. In addition to that, Cyprus is facing a huge problem of dust. Therefore filters in Cypriot construction of windows should be critically used. Cross ventilation principle with supply and extraction of air is a passive house highlight in Cyprus, as well as control units and ducts for ventilation. There is a Sketch-Up plug-in called DesingPH which can be helpful for architects to measure these properties when designing, where one needs to bring into the programme the value-y, i.e. all that is needed for an equilibrium.
A point was made about how there is a minimum boundary for the heating value, however there isn't one for cooling and this is a problem for applying passive houses in Cypriot architecture. In Mexico for example, it is hot during day AND night, thus not a lot of thermal mass is required. Another useful programme here is a thermal bridge analysis programme called Therm made by the University of Berkley.
"When someone wants to build a house, shouldn't he make it as pleasing as can be, since he will live in it, and as useful as possible? Isn't it appealing? A house, when in summer it's cool and in winter it's warm? Now, from our experience we notice that in houses with south orientation, the rays of the sun pass through the covered verandas, but in the summer the sun-path is exactly over our heads and over the roof, so we have shadow..."
Socrates