The Passivhaus standard was originally developed for housing but can be applied to any building. The typical applications include office buildings, schools,hospitals, sport centres, factories, churches and more. In fact, the Bendigo Soldiers’ Memorial Institute recently opened an addition that is designed to Passivhaus standards. It is expected to be the first Passivhaus certified museum in the southern hemisphere, and the first government building in Australia built to Passivhaus standards
Yes. There are no restrictions to opening windows. In fact we use the code standard to determine the required minimum of window openings
Simple physics tells us that it takes a lot of energy to heat or cool air, but very little energy to move air around with a fan. So it makes sense to minimize the amount of air entering the building through air leakage. By making the building airtight you gain control of how the air enters the building.
To prevent the air going stale you need to bring a certain amount of fresh filtered air and distribute it around your building. Because the unit uses a heat recovery unit you are able to transfer most of the heat so that the temperature of the in-coming air is close to the internal air temperature. In the case of the Brinks Flair 325 unit which we will be using in 3 Oakley, the recovery is around 90%
A Passivhaus building takes advantage of the largest free source of energy on the planet, the sun. By orienting the main windows in the building to face north, there is a significant amount of energy gain within the space. Along with the heat given off from the occupants and appliances, this is often all that is required to keep the home comfortable year round.
A ventilation system is still required to provide fresh air throughout the home. The ventilation system transfers fresh air into the home from the exterior while a heat exchanger extracts the wasted heat from the air that is exhausted to the exterior. The excess heat is then recycled within the heat exchanger unit to heat the fresh air coming into the home.
In Adelaide, because we have a fantastic subsoil temperature profile, if we use a suitably detailed slab on ground construction, most of our cooling requirement will come from the ground. This provides us with free air-conditioning. For all of the houses in 3Oakley the cooling requirement is less than a quarter of the heating requirement. The ground is doing all of the hard work. We also need to pay special attention to shading of windows and operable shutters to the East and West windows. Overnight cooling by opening the windows as well as the using the ventilation system summer bypass function are important strategies to ensuring a Passivhaus stays cool through summer
Because of the need for an air-tight thermal envelope you can only use special fireplaces with their own air supply which are a more expensive than the standard type. However, experience in much colder climates than Adelaide (such as New Zealand) show that wood fireplaces introduce far too much heat into the house and tend to go unused.
Laros technologies in Canberra stock an excellent wood burning RAIS Bionic Fire which is extremely efficient and has among the worlds lowest particulate emissions because of its dual combustion chambers
The ventilation system is housed in a well-insulated cabinet and the noise from the fans is no greater than a standard fridge. The units are usually kept in a utility room and which provides good separation from habitable rooms. Because the volume of air is quite low the air passing through the system should be barely audible at normal flow rates
Just as in standard houses, the mechanical system will stop working. However, because a Passivhaus is so well insulated and air-tight, it will maintain a higher level of comfort for a much longer period than a standard house
Passivhaus buildings are extremely energy efficient, requiring up to 90% less energy for heating and cooling. An airtight building envelope and high levels of insulation are the key to minimizing heat loss or gain through the thermal envelope. Reducing thermal bridges throughout external fabric and using high quality windows (at least double glazed) significantly reduces heat loss or gain
A thermal bridge is a weak point in the external thermal envelope. They are basically breaks in the insulation that allow an increased transfer of heat. There are two types, linear and point thermal bridges. A linear thermal bridge typically occurs at a change between element direction or type such as a corner or roof and wall junction. A point thermal bridge might be steel beam penetrating the envelope or a large bolt. These weak points in the external fabric can result in high levels of moisture and mould as energy loss
Your cat or dog door will need to be air-tight and insulated. There are two options with the best option made in Germany and can be linked to your mobile device via your wifi.
You can include thermal mass in your design. In high occupancy buildings it is very beneficial to include thermal mass as it helps balance out peak heating and cooling loads when there is a large influx of people. However, in low occupancy buildings like homes, thermal mass is of minimal benefit because the temperature is always maintained between 20 and 25 degrees C. Thermal mass works best when you have temperature extremes and this just does not happen in a Passivhaus. The Passivhaus institute states that while "the specific heat capacuity has some impact .......... it is actually insignificant in comaprison with other influencing parameters."
There are no license fees. Anyone can build a Passivhaus. If you choose to have your building certified then you have appoint a certifier who will organize the process and will include any fees payable in his charges.
Anyone can build a house using Passivhaus pricnciples. Infact the Passivhaus Institute encourages people to aim to build to the Passivhaus standard. It is a performance based standard. You are not told how to build. You can use local materials and building techniques and support is provided through the Australian Passive House Association. And if you don't quite make it to the full standard, the home you build will be of a much higher standard and have a significantly lower environmental footprint than the vast majority of other houses.
A Passivhaus is more expensive than a basic house built to minimum standards. Newbuilds currently are basically the same as the houses we built 30 years ago with the addition of a little insulation. Not many people would say that what we were building back then was or is good enough, yet we are still producing the same buildings. You need to compare a Passivhaus to a well designed, good quality house using Passive solar design features. These houses will have better quality windows and doors, more insulation, breathable membranes and better shading. In this situation the cost is comparable. The Passivhaus will be about 7% to 10% more expensive to build but will perform considerably better, be healthier and much more comfortable to live in.
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Main picture- Reiselfeld green city quarter in the City of Freiberg, Germany. The worlds greenest city. Since 2011 Passivhaus is the legislated minimum standard for all new residential buildings