Passive House Module, Blog Assignment 1

For my first blog assignment case study I have chosen a recently constructed passive house in Bessancourt, in France.... Blog to soon follow..stay tuned

Irelands first Passive House, 'Out of the Blue'

Out of the Blue was constructed by Tomas O'Leary of Mosart Architects in 2004. The house is  a 4,000sq foot two storey split level house which is located in the garden of Ireland in Co. Wicklow and is the home of Mr. O'Leary and his family and was constructed in Ireland at a time the passive house concept was not very well known. The house maintains a high level of comfort throughout the year using just 10% of the energy of a conventional house, achieved through high levels of insulation, southern orientation, air-tight construction and mechanical ventilation with heat recovery. The latter refreshes the air in the house 12-times daily, so the house is also very healthy. As the house is a lived in family house and the first of its kind in Ireland it has naturally received huge public interest and its associated details can be seen on the Mosart website.


'Out of the Blue'-Irelands first Passive House

The construction of this house using these methods was revolutionary for the Irish construction industry and increased the interest in this building methodology while showing potential clients that it is in fact possible, comfortable and affordable. The building is also not one which is visually polluting and in fact has the look of a normally constructed house. There are however many different technical and construction details which were and are to this day used in the running of the building. The house has a constructed outer leaf of block cladding with 315mm of EPS insulation which can be seen in-situ in the linked Construct Ireland article. Some of the other details of the construction include the house being south facing, having a heat recovery ventilation system which is certified >90% which was supplied by Produkt Ltd and also having 7.2m sq of solar supplied by Eco-NRG Wexford. There is also much more technical data which can be seen in the technical overview of the house supplied by Mosart and an associated project data sheet which is available from the passive house insitiute online. Both of these pieces of information give all the relevent information in regards this build including u-values and appliance information along with the companies who supplied and installed them. Another great aspect of this build is that most of the fixtures and fittings were all supplied form Irish companies showing that we have had and currently possess both the knowledge and technology to fully introduce and adopt the house in the Irish construction industry.   


First Steps

The Passive House (PH) technique is fundamentally a method rather than a specific building style. While several PH building techniques have been developed to suit the European climate it is important that these are not just copied without assessing and developing a specific solution for each area and climate. This is because of the massive differences in elements such as solar gain between different climates, e.g. Sunny California and Dreary Galway. While the climate changes the concept and laws of physics remain the same around the world in different climates. Although the designs of PH may appear quite different, the principle remains the same of reducing investment through energy efficient design (Lovins). When the heating load is less than 10 W/m2, independent of climate, the ventilation system can easily be used for space heating and then a separate heating system is no longer required. While there is an associated extra capital cost during the construction stage of PH compared to traditional methods the costs would rise much more dramatically if the goal was to achieve a 'Zero Energy House' instead of a PH as well as there being almost no additional environmental benefits. These PH's have a very low energy demand for maintaining interior comfort in the heating season. Examining the heating load is just one example in other regions other energy services may be of greater importance than that of heating. As stated earlier it is important to investigate the specific PH solution for each separate project with each one being different and unique. In this case the different technologies available, ventilation systems for thermal comfort and various other associated methods should all be investigated. There are also some rules of thumb to be followed, such as

Keeping Comfort to a high level.
Solutions should be simpler than what is used conventionally.
Insulation is highly recommended in all climates.
Shading is paramount in all climates with high radiation levels.
Heat recovery is necessary in all climates be they hot or cold.
The use of very low auxiliary energy is of great importance.
And in Many cases the ground may be used as a heat or cold buffer.

After defining the goals in different climates the next step is to perform a 'computer based parametric study' of the design solutions and to check the results. A traditional building design can be used as a starting point, then each element can be modified step by step.