The self-sufficient house - An overview

Self-sufficient houses have become a much-discussed topic in recent years and a much-mentioned term - but with different meanings. All in all, living and building "Off The Grid" is seen above all as a topic of the future and for some as a way to more sustainability. However, in many cases this is only partly true - and in addition, the right framework conditions for self-sufficient housing and construction must be given - even if self-sufficient houses were even more the rule than the exception some 150 years ago, this is often difficult today,

What does "self-sufficient" mean?

The term "self-sufficient" in its basic meaning means something like independence - and freedom from external influences and achievements. And that's where the conceptual dilemma begins. For some, self-sufficient houses are already those that produce their own electricity, while others only allow genuine self-sufficiency - that is, complete independence from all types of utility networks.

In this sense, the American term "off the grid" is used differently. In Germany, a complete independence of all supply networks is not possible, even for reasons of building law.

And for a correct definition of terms, one would have to consider whether a road development of a house is already a form of care. At least in the strict ecological sense, it too is a massive invasion of the environment beyond the single house.

It always depends on how you define the word "self-sufficient".

Energetically self-sufficient houses

In the current usage is meant - at least within the mass media - with "self-sufficient" above all energetically self-sufficient. However, this includes every residential building with a photovoltaic system on its roof that does not draw its electricity from the public grid. This is no particular achievement in terms of the state of technical development today.

Quite apart from the fact that a basic connection to the network must be present in most cases - on the one hand, because the construction of the house usually building electricity is needed for the construction machinery, on the other hand because when feeding back surpluses of electricity into the public network yes Connection to this network.

From an ecological point of view, this could also make more sense by giving and taking over an existing network, instead of storing surpluses locally and doing business on a single object - but opinions have diverge so far.

Fully self-sufficient life

Complete self-sufficiency is still a beautiful future dream in Germany - which does not work for legal reasons alone. At least one connection to the sewage system must be made, so that is usually inevitably a connection to the water supply network connected. Only a sewage system may be built. The use of rainwater as drinking water is also banned in Germany.

Advantages and disadvantages of self-sufficient houses

Again, one must illuminate the individual self-sufficiency terms separately, always depending on what is meant. Energetic independence - that means the self-sufficiency of electricity and heating - has of course its advantages:

Advantage 1: Independence

Independence from public networks and the price policy of the public providers, as well as of the state, which profits indirectly from the public supply also quite a lot of taxes, is of course a clear advantage.

Advantage 2: Cost reduction

Apart from the necessary initial investment, this also means a significant reduction in costs and cost certainty for the future beginning with amortization, which is not the case for grid-dependent houses. They are always dependent on the price ideas of locally available energy suppliers and the political ideas for green taxes and tax surcharges. In a complete self-sufficiency, this advantage would extend to water and wastewater costs, but as already mentioned, this is not technically possible.

disadvantage

The most important disadvantage is especially in the area of ​​reliability and the elimination of the need for own storage of energy on site, which is technically not yet particularly well solvable and usually extremely expensive. In a complete lack of connection to an existing power grid is connected in case of failure of the system with a loss of electrical energy and in most cases also from heating and hot water.

Particularly in winter, big problems can quickly arise here, especially if the supply can not be bridged due to the lack of an existing network connection. In this case, provision must be made accordingly - which means a further cost. It is of course possible - even with today's technology.

Autarkic technologies at a glance

1. electricity

Electricity for a self-sufficient home can be obtained in a variety of ways - from photovoltaics, from a combined heat and power plant, from a windmill or wind turbine on the roof, or through a combination of different possibilities. Photovoltaic is the most commercially developed area, and in recent years the cost of technical equipment has fallen sharply.

For a true independence of the network, however, it also requires storage technologies that can bridge either sunless times or failures of the system - but here the technology is still expensive and not as powerful as it should be for these purposes.

2. Heating

Heat from heating is already produced largely independently today - whether it is the classic oil boiler or heat pump technology. District heating is only an issue in a few areas today, the majority of homes today are already self-sufficient heating technology.

Making a connection with the respective self-sufficient power generation, also for the hot water, would of course make sense as an overall concept - as in the combined heat and power plant.

3. Water

Water supply via rainwater is theoretically possible, and with minor restrictions the precipitation amounts are quite sufficient for a single household, assuming adequate storage.

The use of rainwater is allowed in Germany but only for garden irrigation and toilet and washing machine. It must be present for two separate circuits in the water pipe system and proven. In addition, waste water charges have to be paid for all rainwater runoff - whether it is used or seeped.

4. Wastewater

For the disposal of accumulating wastewater on the one hand also offer the previously used septic tanks, on the other hand, a separate reprocessing of water, which today is technically complex but in accordance with designed small systems for a single house also possible.

Compost toilets are a great way to dispose of fecal matter. Sick pits are now only permissible where there is no sewer system, and yet a building permit is issued - such areas exist in Germany but at most only a few, if any.

A connection to the public water and sewer system is virtually inevitable today. There is no autarky here, and that will not change that fast.

The price of independence

The cost of producing self-sufficiency - where permitted by law - today is extremely expensive. The required technology is still complex and represents a high capital expenditure that has to be reckoned with. At some point he does that but still.

Purchased "concept houses"

Today you can even order "self-sufficient prefabricated houses" - as a rule, these are only low-energy houses with their own power generation via photovoltaic, not a particularly successful design. However, such houses are still far away from an actual self-sufficiency - precisely because these are usually not allowed in many areas for legal reasons. And you can also build a low-energy house with a PV system yourself, which is not a special technical development.

But overall, the topic is a very potent buzzword - many people seem to want independence and self-determination, above all, independence from inscrutable prices and guided price increases, as well as political tax blackmail from basic supplies like energy. Thus, autarky has become a kind of magical word, which is very attractive.

Alternative living concepts that can support self-sufficient technologies

In the field of alternative and sustainable building, there are some living concepts that include self-sufficient care in their concept from the outset. Although few of these projects would ever receive building permits, at least they are just concepts. Interesting are approaches such as EarthBerm Homes and houseboats or so-called Floating Homes, such as built in Hamburg as a model project.

Also a very interesting trend towards minimal living in very small but cleverly organized houses and container houses that can be transported by truck or low loader and can be placed anywhere are just some of the planning considerations that make a large number of designers and architects,

So far, the narrow legal bases allow practically no different from the traditional single-family dwellings - but this might eventually change in the wake of pressure from the public and the desire for new, more ecological or simply modern ways of housing at some point, and in the wake of these changes then perhaps new possibilities for the self-sufficiency of a residential building will be allowed. If anything, then there is certainly a lot of water flowing down the state-controlled and metered lines.

Video Board: Future homes: Self sufficiency