Low Energy & Passivhaus
Imagine living in a comfortable, modern house with no cold drafts, no temperature variations from room to room, and, best of all, virtually no heating or cooling bills – sounds too good to be true!
The term Passivhaus (or Passive House) refers to an advanced low energy construction standard for buildings, providing excellent health and comfort conditions – being both cool in summer and warm in winter – with minimal heating or cooling requirements and reducing its ecological footprint. Passive design is not an attachment or supplement to architectural design, but a design process that is integrated with architectural design.
What does living in a Passivhaus mean for you?
• NO HEATING SYSTEM – Passivhaus house design eliminates the need for traditional heating systems in even the most challenging climates, so bills for heating oil, gas or propane could become a thing of the past.
• COST SAVINGS – The extremely low energy consumption of a Passivhaus often results in cost savings to the occupier of a Passivhaus building of more than 90% per year, compared to ordinary buildings.
• COMFORT – The notion of comfort is so integral to the PH concept that the Passivhaus Institut has gone so far as to apply a “comfort equation” to its building process [source: Feist]. Passive house design strives to maintain a comfortable, even temperature throughout the home, with low temperature variations from room to room. High-performance windows and superior insulation also help to keep the inside of the passive house extremely quiet.
• HEALTH BENEFITS – Allergy sufferers and asthmatics have confirmed that they find Passivhaus buildings to be extremely comfortable and allergen-free, a fact that is primarily down to the filters. The air is circulated around the house, and a constant zero pressure gradient between the outside and the interior is achieved by a specially-designed system, which maintains the pressure balance in order to prevent air from being drawn in or leaked out, which would create a draught. As the air is drawn through the system, filters remove airborne particles to ensure a fresh and healthy feeling.
• PEACE & QUIET – The high-performance windows and heavily insulated doors and walls in a passive home, greatly reduce exposure to street noise and other outdoor sounds. Inside the house, Passivhaus Institut requirements specify that the efficiency of the central heat exchanger should be high, energy consumption of the fans should be low, the operational conditions should be clean and the unit should be very quiet.
• FRESH AIR – Passivhaus buildings provide a plentiful supply of fresh air internally to ensure low C02 levels whatever the season, and to provide perfect air humidity levels for healthy conditions all year round.
• CONSISTENT TEMPERATURE ALL YEAR ROUND – Passivhaus buildings have fully openable windows, but provide excellent winter ventilation without wasting heat, and without cold winter draughts. In the summer the Passivhaus is ventilated by opening the windows, but in winter to save energy, ventilation is normally achieved by a low-energy heat recovery ventilation system.
• BUILD COST – Passivhaus buildings save the cost of a conventional heating system, and this means they can now be built for little or no additional cost compared to ordinary buildings.
• THE COOLNESS FACTOR – We think they are extremely cool buildings, and everyone wants one!
Can building just one passive house stop pollution or global warming? Sadly, no. But if even a small percentage of the new homes and buildings constructed in the UK and elsewhere were built to passive house standards, the energy savings would be significant.
The Passivhaus standard requires that the building fulfills the following requirements:
• The building must be designed to have an annual heating and cooling demand as calculated with the Passivhaus Planning Package of not more than 15 kWh/m² per year (4746 btu/ft² per year) in heating and 15 kWh/m² per year cooling energy OR to be designed with a peak heat load of 10W/m²
• Total primary energy (source energy for electricity and etc.) consumption (primary energy for heating, hot water and electricity) must not be more than 120 kWh/m² per year (3.79 × 104 btu/ft² per year)
• The building must not leak more air than 0.6 times the house volume per hour (n50 ≤ 0.6 / hour) at 50 Pa (N/m²) as tested by a blower door.
The Passivhaus standard can be used on many types of buildings; offices, schools, gyms, so it is by no means limited to housing. On a similar note, Passivhaus is not prescriptive of the construction method; one could build a timber frame house, a masonry school, or a reinforced concrete frame 10 storey office block, all of which can achieve Passivhaus performance.
Graphic Illustration of house (Placeholder image)