FAQ

Air-tightness is essentially a requirement for all new buildings in Ireland under Part L (conservation of fuel and energy) of the most recent building regulations (2011).

Air-tightness is achieved by the installation of an airtight membrane throughout the fabric of a building, this prevents heat loss by eliminating drafts. Correct installation by an experienced fitter with good quality materials ensures optimum indoor air quality and thermal comfort all year round.

Air-tightness testing measures the amount of air flow entering and leaving a building, measuring the ACH (air changed per hour), this measurement verifies the quality of the installation of the airtight membrane. Air loss can occur through gaps and cracks in the fabric of a building. The method used to test the level of air loss within a building is called the blower door test.

Air tightness testing and thermal imaging can help identify and highlight the areas within a building where heat is escaping.

Yes, windows can be opened in an airtight house, however there is no need to open windows as the MVHR ensures every room in the house has a constant supply of fresh air 24 hours a day.

However, leaving windows open in an airtight house with an MVHR during the Winter months, will make the system less efficient.

The U-value is the measurement of the rate of heat loss through one square metre of a surface. The lower the U-value, the lower the rate of heat loss. A lower U value means your house will be warmer and more comfortable and less energy is required to replace heat lost, resulting in lower energy bills.

A thermal bridge/cold bridge/heat bridge is a path that has significantly higher heat transfer than the surrounding area. Thermal bridges are created when materials that are poor insulators come in contact, allowing heat to flow through the path created.

Insulation around a bridge is of little help in preventing heat loss or gain due to thermal bridging. The bridging has to be eliminated, rebuilt with a reduced cross-section or with materials that have better insulating properties, or with an additional insulating component a thermal break.

Building a Passive house is becoming increasingly cost effective to build, as materials and technologies used become more mainstream as Part L building regulations improve. Ever increasing energy costs for heating will not be an issue in a Passive house. Comfort levels are raised to a much higher level and the indoor air is healthier for occupants living in a Passive house.

Not necessarily, because the methodology to verify a house meets Certified Passive Standard is different from that used to verify a house meets Part L requirements (BER rating), the assumption cannot be made that a passive house is automatically an A-rated house.

The BER method assesses heating, hot water, lighting and ventilation, whereas the passive design method includes all appliances in its calculations as well as those covered by the BER method, but accounts for them differently.

Part L regulations include a requirement for a proportion of the primary energy demand of the building to be supplied by renewable energy source. Passive house design minimises the requirement for any heat source in addition to solar gain.

Thermal imaging is the use of a high tech infra-red camera to identify areas of heat loss within the building fabric that is are not detectable by the naked eye or an air-tightness test.

The BER method assesses heating, hot water, lighting and ventilation, whereas the passive design method includes all appliances in its calculations as well as those covered by the BER method, but accounts for them differently.

Part L regulations include a requirement for a proportion of the primary energy demand of the building to be supplied by renewable energy source. Passive house design minimises the requirement for any heat source in addition to solar gain.

Passive house standard windows are a key component in a passive building. Passive windows are super insulated and trap solar gains within the building.

Passive house windows are typically triple glazed (to ensure correct U-value is achieved) and have insulated frames to minimise heat loss.

Standard windows are not typically triple glazed and they don’t have insulated frames. The use of standard windows in an airtight building will cause a huge temperature difference between the window and the walls, this will likely cause problems with cold bridging and condensation.

The BER method assesses heating, hot water, lighting and ventilation, whereas the passive design method includes all appliances in its calculations as well as those covered by the BER method, but accounts for them differently.

Part L regulations include a requirement for a proportion of the primary energy demand of the building to be supplied by renewable energy source. Passive house design minimises the requirement for any heat source in addition to solar gain.

Yes, at Mannion Passive House Builder we have the expertise to build using three building systems.

Your project can be built using blocks, timber frame or ICF (insulated concrete form). The choice of building system is a personal one and we are happy to discuss these options to help you make your decision, contact us today.

Passive house windows are typically triple glazed (to ensure correct U-value is achieved) and have insulated frames to minimise heat loss.

Standard windows are not typically triple glazed and they don’t have insulated frames. The use of standard windows in an airtight building will cause a huge temperature difference between the window and the walls, this will likely cause problems with cold bridging and condensation.

The BER method assesses heating, hot water, lighting and ventilation, whereas the passive design method includes all appliances in its calculations as well as those covered by the BER method, but accounts for them differently.

Part L regulations include a requirement for a proportion of the primary energy demand of the building to be supplied by renewable energy source. Passive house design minimises the requirement for any heat source in addition to solar gain.

www.passipedia.org

The design of a Passive House is essential to the energy performance of the house, see key components for further details. Certified Passive House Designer is an internationally recognised qualification from the Passive House Institute.

The Passive House Institute maintain a database of all certified passive house designers worldwide.