The ‘passive house movement’ is suited best to cool temperate regions. Dwellings are hyper-insulated and very airtight, and some slash their heat demand by about ninety per cent.
For cool climates, such as those encountered in Tasmania, heating can represent a whopping fifty per cent of domestic electricity use. This reinforces the importance of insulation in keeping down bills and curbing carbon emissions.
In the Northern Hemisphere, German and Swedish scientists and engineers collaborated to create the passive house standard, which was established in the early 1990s. Suited best to cool temperate regions, such dwellings are hyper-insulated and very airtight. As a result, some only require passive heating (i.e., heat from cooking) to keep warm, while others slash their heat demand by about ninety per cent and enable far smaller heating systems to be installed. To achieve airflow, ventilation strategies are used, but, due to slower-than-average air circulation, it is recommended to avoid sources of indoor chemicals that can include outgassing from new carpets and furniture. Passive house designs are frequently complemented by passive solar, solar panels on the roof, and energy-efficient lighting.
The passive house movement began in German-speaking countries and Scandinavia, but is increasingly spreading further afield, and includes a few in Australia. Initially restricted to domestic houses, it now extends to a range of other buildings, including supermarkets, tower blocks and schools.
An important breakthrough was made for passive houses in February, 2016, when Dún Laoghaire-Rathdown County in south-east Dublin voted to adopt the passive house standard for all new buildings. The first of its kind in the English-speaking world, this motion was supported by councillors from nearly the whole political spectrum.
Then, in May 2016, Dublin City Council passed a very similar motion that had been put up by the Green Party. Taking such a bold and proactive step is never straightforward, and in June Dublin’s unelected planners rejected the policy. However, this is not a done deal, and there will be pressure for passive house rules to be reinstated in the city’s development plan when it is finalised in November.
In the case of Ireland, passive house advocates argue that construction will incur no extra cost. For new Irish homes, a sixty per cent energy reduction target is already bringing construction methods close to passive house territory, and it will be fairly easy to piggy-back on top. In Ireland, construction represents only about 40 per cent of the cost of a new residence, and in countries where added costs apply, these have been estimated in the 5-10 per cent range. If there are any additional costs in Ireland as a result of these policies, they would be very small, comparatively speaking.
For communities in Ireland, fuel poverty is a pressing issue, and it could be argued that the benefits of a huge reduction in heating costs outweigh a potential tiny increase in building costs.
Elsewhere in Europe, mandatory passive house development standards have been passed in countries including Germany, Austria and Belgium. This is helping to boost their numbers, which currently stands at 60,000 and are rising steadily. With new houses built within the EU required to be ‘near zero energy’ by 2021, it would be difficult to reach this goal without a massive shift towards passive house-standard developments.
Passive House Australia www.passivehouseaustralia.org
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