Much ado about zero energy buildings

With the European Parliament mandating under the amended ‘Energy Performance of Buildings Directive’ that all new buildings are to be ‘zero energy’ by 2019 the heat is on to produce architecture and environments that contribute to more sustainable energy equations with a zero or positive bottom line.

According to 2006 figures from the US Department of Energy, energy use in the building sector in the US continues to increase “primarily because new buildings are constructed faster than old buildings are retired.” Essentially the net building stock in the US is increasing. The government is not predicting any reduction in demand for new buildings and so is pursuing a Zero Energy agenda. The authors of the report ‘Zero Energy Buildings: A Critical Look at the Definition’ say “because design goals are so important to achieving high performance buildings, the way a ZEB goal is defined is crucial to understanding the combination of applicable efficiency measures and renewable energy supply options.”

Under the (Zero Energy Building) ZEB definition four aspects of energy are considered: 1) net-zero site energy 2) net-zero source energy 3) net-zero energy costs and 4) net-zero energy emissions.

Chicago architect Zoka Zola has designed a zero energy urban home with a green roof for passionate gardeners. The green roof is designated as the zone for the home to extend in the future and for the installation of renewable energy infrastructure. The accessible green roofs encourage “bio-diversity and absorb water runoff, while insulating the interior and protecting the roof from thermal shock and ultra violet deterioration.” The tree in the south facing garden provides both beauty and summer shade. The garden also provides the outlook from the rooms with large south facing windows.

With designers giving functional, structural and aesthetic consideration to the zero energy buildings the green future is looking bright.

10 thoughts on “Much ado about zero energy buildings

  1. Tom Turner

    The EU’s environmental legislation is one of the best things it has done and I am very much in support of Zero Energy Buildings. Since I do not enjoy frothing at the mouth, I prefer not to think about the Common Agricultural Policy which is such a dangerous cause of Mad Environmentalist Disease (MED).
    There is a great need for experience and expertise in garden roofs and for adjusting their design to local circumstances. The roof for 2305 W. Adams Street MAY be right for Chicago but it would not be right for a passionate gardener in London. Zoka Zola say ‘The tree in the south garden gives beauty and summer shade.’ It will. But in London it would keep out too much sun. Except for a few weeks/year, we need it to keep us warm and the plants need it to flourish. Some plants survive in shade but not many of them enjoy being deprived of light. Summer shade is more important in the summer heat of Chicago but wouldn’t even a deciduous tree with a light canopy could make a room gloomy in winter? The oldest way of dealing with this problem is a removable awning made of rushes and branches.

  2. christine

    Yes. I recently read somewhere about the unique gardening culture of England as opposed to the lawn culture in the United States.

    Perhaps the CAP could be given a mixed report card?

    The production of biofuels, as advocated by the CAP, uses valuable agricultural land and impacts on food prices and availability. BSE was an early scare for the sector, resulting in an increased empahsis on food safety through concerns for animal health. The GM sector is another area of food safety controversy. Perhaps policies and measures need to be taken on both a sectoral basis, differently by different states and at the level of the individual farmer for the objectives of food safety to be successful?

    However the organic agricultural sector and agro-environmental measures looks to be some of the CAP success stories.

    The CAP is also to be applauded for ensuring that the EU is self-sufficient in food productin and (without production limits) is capable of producing a surplus of food for export. Today the EU is a net importer of agricultural products, particularly from developing countries. I am supposing that this is the result of economic and trade imperatives?

    It would be interesting to understand the components of food production from the member states given that there is concern about the capacity of the UK to meet its future food needs. In this context green roofs can perhaps contribute to increasing individual food production opportunities and the total extent of cultivation for food. However, the environmental quality of cities and resource availability (water, energy etc) will be an important caveat on food quality and safety standards.

  3. Tom Turner

    I know that it is dangerous ground to be on, but it is possible to find some virtues in Adolf Hitler: he liked painting, architecture, local traditions and vegetarians. I think looking for virtues in the CAP is also a challenge but, as you say, may be possible. Some people have the same view of the EU. I argue that (1) at its best, the EU presents a wondeful model for how neighbouring states and states-within-states can co-operate (2) at its worst, it follows in the path of histories other megalomaniacs (3) one of the best things it does relates to environmental policy.
    Do you think it is too soon for countries to mandate that, with a timetable, all future housing will be (1) off-grid (2) accessible without carbon-powered vehicles (3) able to grow a proportion of their own food (4) able to detain and infiltrate rainwater within the property boundary.
    What else is required to achieve genuinely sustainable housing?

  4. Christine

    My preference is for a state by state approach to energy policy and the flow on implications for housing. For example, only 19 percent of Iceland’s energy comes fossil fuels (mostly oil). All electricity is 100 percent from renewable sources:

    “The move from oil-based heating to geothermal heating saved Iceland an estimated total of US $8.2 billion from 1970 to 2000 and lowered the release of carbon dioxide emissions by 37%.”

    In Iceland the intention is to reduce its dependency on oil (for vehicles and fishing vessels)by becoming a hydrogen based society by 2050.

    Because of its existing energy profile there is no energy security/emissions/cost imperative for off the grid housing in Iceland.

    In regional and remote Australia there is considerable value in off-grid housing because the transmission distances involved and the high reliance on fossil fuels for electricity generation. The majority of properties are currently located beyond the grid. Many are powered by diesel based generators.

    Transportation in these areas is an essential component of the rural and remote lifestyle (work and home) and is fossil fuel dependent. The iconic Australian airlines Qantas was formed to connect regional towns by air.

    The value of harnessing the advantages of the remote location of outback Australian cities, with both off grid and on grid alternatives is demonstrated by Alice Springs’ commitment to its solar city status, [ ] including construction of the largest tracking solar power station in Australia.
    [ ]

  5. Tom Turner

    ‘Yes’ to every locality taking its own path to energy generation but ‘No’ to societies burying their collective heads in the sand (about the need to move away from oil economies).
    “Pharaoh dreamed that he stood by the river, and out came seven fat cattle, who fed in the reed-grass. (Genesis 41:1–2.) And then seven lean cattle came up out of the river and ate the seven fat cattle, and Pharaoh awoke. (Genesis 41:3–4.) He went back to sleep and dreamed that seven good ears of corn came up on one stalk, and then seven thin ears sprung up after them and swallowed the good ears, and Pharaoh again awoke. (Genesis 41:5–7.)” Metaphorically, we are at the end of the fat years and I think it would do the world a lot of good if America raised its energy prices to European levels and began investing the extra revenue on building energy-efficient cities with green transport, passive air-conditioning, urban agriculture etc etc

  6. Tom Turner

    I am so often overtaken, on by bicycle, by big busses spewing diesel fumes into my lungs, AND WITH ONLY ONE OR TWO PASSENGERS ON BOARD, that I am becoming sceptical about bus-transport being green. I think it is as much, or more, a social policy for people who do not have cars.

  7. Christine

    Perhaps it might be possible to introduce a minimum passenger rule for all transport.

    For example 1 cyclist per cycle, 1 motorcyclist plus 1 passenger per motorcycle, minimum of 3 persons per four seat car trip etc.

    So a one person household for example could only ever cycle unless they carpooled with at least two others on trips…

    No wonder transport efficiency is such a difficult aim to achieve! I think this guy was having a similar sort of day as he contemplated the carbon-foot print of the cycle.
    [ ]

    The definition of an ecological footprint by Rees in ‘From sustainable transport: planning for walking and cycling in urban environments’ is:

    “The ecological footprint of a specified population is the total area of land/water required, on a continuous basis, to produce the resources that the population consumes and to assimilate the wastes that the population produces wherever on earth the relevant land or water is located. (Rees 2001a).”

    Globally, about 15 percent of manmade carbon dioxide comes from cars, trucks, airplanes, ships and other vehicles. Diesel is said to be more emissions intensive but also more efficient as a fuel than petrol. So maybe one big bus with 2 passengers is less polluting than one average sized car containing the same two people?

  8. Tom Turner

    Conceptually, I can see that Ecological Footprint has some attractions. Say I build, as I would like, a zero-carbon, zero-runoff, off-grid home and use the walls and garden space to grow my own food (partly by aquaponics). Does this give me a big ecological footprint (because it would be expensive) or a small ecological footprint? Applying the calculation to populations is easy and not much use. Individuals need to be persuaded to take the necessary steps towards sustainability.

  9. Christine

    Having looked at the problem of the ecological footprint on a individual person (per capita basis), a state basis (a nation state) and on a regional basis (a number of ecologically interdependent nation states) which ultimately impact on the global commons, it seems that an approach that captures the complexities of all levels and their inter-dependencies is essential.

    Consider if your home was located near Sendai in Japan, all of the features you have listed would not have assisted the ecological sustainability of your residence.


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