Fin MacDonald

Information on me and my current projects

Monthly Archives: March 2012

Ireland PassivHaus Retrofit Report

Last week our Ireland project wrapped up and we submitted our final report and did a presentation to students at I.T. Carlow in Ireland with our findings. Our group consisted of:

  • Myself
  • Karyn Brown from Holland College in PEI
  • Deirdre Cahill from I.T. Carlow in Ireland

The project was to develop a retrofit plan to upgrade and existing Irish home to meet the PassivHaus standards. Our group did an excellent job. Just to recap, the PassivHaus standards require:

Heating: 15 kWh/m2 each year
– or -
Peak Load: 10 W/m2
- and -
Total primary energy use: 120 kWh/m2 each year
– and -
Air tightness less that 0.6 air changes per hour at 50 pascals
– and -
No thermal bridges (The co-efficient of heat transfer needs to be below a certain value)

The real challenge was meeting the heating load. The building was not orientated in a way that it could benefit from passive solar gain from the sun. It had west/east facing front/back/roof. The building had a heating load of 121 kWh/m2, and we needed to reduce this to 15 kWh/m2. We accomplished this with the following upgrades to the building:

  1. 200 mm of rigid polystyrene insulation was added to the exterior of the home
  2. 60 mm of polystyrene beads were pumped into the cavity of the wall
  3. All windows were replaced with triple glazed PassivHaus windows with a U-value of 0.58 W/m2*C
  4. All doors were replaced with PassivHaus certified does with a U-value of 0.58 W/m2*C
  5. 200 mm of rigid polystyrene insulation was added to the attic
  6. An air barrier was added to reduce air infiltration

Once the envelope was upgraded to meet the 15 kWh/m2 requirement the home also met the 120 kWh/m2 total energy use requirement. This is because the occupants didn’t use very much energy at all for appliances. This was discovered through analysis of the energy bills.

The payback for the upgrades was not very favorable. It required over 30 years to reach equity payback, and in the 50 years remaining in the buildings life this produced a net present value (NPV) of over -20,000 Euro. Some of the upgrades had a larger impact for every Euro spent, and we did our best to prioritize them for the client. We concluded that PassivHaus is a great tool for energy efficiency but it is not always practical to upgrade a home all the way to the PassivHaus standard. It is only achievable within a reasonable budget when free solar energy from the sun can be used to reduce the heating load of the building.


I have attached a copy of our final report here. It contains more detailed information about the project and our upgrades.

Students and faculty involved in the Ireland Exchange

Receiving my certificate from Dan O'Sullivan of I.T. Carlow

Cloughjordan Eco-village

Recently I visited Ireland’s most sustainable community, an eco-village located in the town of Cloughjordan. Approximately 80 people live inside the village, and the organization has over 150 members. The company incorporated in 1999 as a not for profit educational charity. The organizational structure they use is a hybrid between a cooperative and a limited company.

The eco-village integrates permaculture, eco-logical design, green production, alternative energy, and community building practices. By doing so they create a modern community where it is easier to live sustainably.

The layout of the eco-village is 1/3 developed with buildings, 1/3 farmed, and 1/3 woodland. Medium density homes with proper solar orientation are used. Maintaining the eco-logical diversity of the area is important to the members, and everyone builds following an ecological charter that was drafted by consensus. Homes are built using several different construction methods, but the most common are cob structures or timber frame with lime and hemp walls. PassivHaus guidelines are followed whenever possible. The community is orientated for walking and cycling, although cars are allowed.

A community farm was created and is cooperatively run. Over 50 households are members. You are not required to be a resident of the eco-village to buy in to the community farm. All produce is placed in a central location where families can pick up what they need, with respect for the quantities available and the others needs.

All heat and hot water is provided by renewable energy. A 500 collector solar hot water system is used, which is the largest residential system in Ireland. Two wood chip boilers use waste biomass from a fence post manufacturing plant to provide the rest of the heating supply. There are plans to add electricity generation in the future, but the approach to that is yet to be decided on.

The eco-village is working to develop green businesses. There are 16 live/work units in the village, as well as an eco-hostel. Micro businesses, educational spaces, and a green enterprise center are also in the village.

The village attracts all kinds of different people from different ages/backgrounds. They are generally interested because of their social, ecological, or organizational views. Most people enjoy the community theme and many new residents move there looking for something different and exciting.

I attended experience day, which included a presentation and a tour. They are held weekly to provide information and to recruit new residents for the village. At the session I found retirees looking for a place to retire, a young family with a young child looking for a high level of community, and some others who were genuinely interested in helping the planet. Attending was a great experience for me because we don’t have communities like this on the east coast of Canada. This type of community would have been similar to what my great grandparents would have lived in, minus of course the technology. It is fascinating that we are headed back in that direction. The sense of community is very special.

The Community Farm

A sustainable home built from Cob

The Village Solar Hot Water System

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