What is a Passive House?
A Passive House combines high level comfort with very low energy consumption. A Passive House makes efficient use of the sun, internal heat sources and heat recovery ventilation to such a standard that conventional heating systems are virtually rendered unnecessary.
A Passive House enjoys a comfortable temperature winter or summer and much higher air quality than traditional construction.
A Passive House is a healthier house that controls dust and pollen associated with hay fever and other allergies. A Passive House controls humidity, eliminates mould and condensation which is associated with asthma and other respiratory illnesses. A Passive House does not have a specific construction method and can be constructed from any construction materials, even concrete!
What is so special about a Passive House?
1. Exceptional high level of thermal insulation.
2. Well insulated window frames and triple low-e glazing.
3. Thermal Bridge free construction, requiring a high level of design and drawing detailing.
4. Airtight building envelope – no draughts.
5. Healthier air quality with highly efficient heat recovery ventilation.
6. Better building quality.
Advantages of a Passive House
1. Extremely low heating costs – even with rising oil prices.
2. Healthier living environment, with dust and pollen reduction, controlled humidity and free of mould and condensation.
3. High level of comfort – constant indoor temperature.
4. Greener and more environmentally friendly homes due to the huge reduction in CO2 emissions associated with space heating over the lifetime of the house.
Facts and Figures
A Passive House uses no more than about 1.5 litres of heating oil per year for every square metre of living space. At today's energy prices this equates to circa €1.25/m2 per year in space heating costs. This is approximately a tenth of a traditionally constructed house to current standards.
Passive House Planning and Detailing
A critical element to Passive House construction is the Passive House Planning and drawing detailing. Before construction can begin on-site all Passive House Planning and detailing must be carried out. This is calculated accurately using Passive House Planning Package software (PHPP) developed by the Passive House Institute, Darmstadt, Germany. Issues that the Passive House Designer would assess at planning stage would include the orientation, solar gain for windows, sun protection for overheating, cross ventilation in summertime, thermal bridge free detailing, shape and proportions of structure, overshadowing, U-Values of heatloss elements, domestic hot water usage, boiler type, airtightness and ventilation.
Tried and Tested
Several hundred Passive Houses have been scientifically monitored and rigorously tested. The consistently positive results are convincing. Thousands of Passive Houses have already been built, occupied and proven efficient, even in the extremely cold climates of Scandinavian countries. The Passive House Institute, Darmstadt, Germany are the body given responsibility to assure standards are adhered to. Certification from the Passive House Institute is confirmation that the highest of energy standards have been achieved.
The Passive House Technical Criteria
The design criteria set out by the Passive House Institute includes the following:
1. Specific Space Heat Demand: Max. 15Kwh/m2.year.
2. Pressurisation Test Results (n50): Max. 0.6 airchanges/hour
3. Entire specific Primary Energy Demand: Max. 120Kwh/m2.year
Achieving the above criteria is required to achieve the official Passive House Certification.