House In A House

The Bio-Solar-House Principle

This article was originally published by the patent holders and inventors at You can find more in-depth information at their website.

“Nature beats technology! Nature is infinitely superior to technology, physical processes operate more sustainably than machines.”

– Engineer & Bio-Solar-House inventor Klaus Becher

Nature’s building principle a house in a house

No Plastic Bag!No plastic-bag, no ventilation. The decisive difference to all other low energy houses is: Bio-Solar-Houses need no moisture barriers and no ventilation systems! A partly glazed weather-protected house heats up like a greenhouse with the daylight sun. The thermally well-insulated house cladding of the inner timber house heats up from outside. The vapours produced inside the house by the occupants diffuse together with the associated odours, into the air space between the inner house and weather protected outer house, without any damaging condensation occurring – the diffusion-open inner house cladding allows it to dissipate straight through. From there it flows outside naturally by means of its gaseous form through the openings. In this way, the principles of nature render moisture barriers superfluous for protecting the house cladding from condensation damage, and so too are possibly problematic ventilation systems for dehumidification of the living space rendered obsolete.

The correct use of the laws of nature makes the energy efficient building system of the Bio-Solar-House so uniquely healthy, economical, future-proof and environmentally sound.

A Bio-Solar-House, in contrast to other energy saving houses, requires no expensive moisture barrier and no problematic ventilation system. It permanently protects the health and finances of its occupants. The well-known problems with destructive damp, mould which is hazardous to health, viruses, bacteria, legionella and various allergenics are absent in the Bio-Solar-House by its very construction.

House In A HouseIt’s a house in a house: energy-saving radiant heating promotes your health and feeling of well-being. Due to the layer of air between the weather protected house and the inner cladding, the inner house is kept as warm as an overcoat even in the coldest winter. A Bio-Solar-House loses much less heat to the surrounding cold air than every other house. Therefore it needs considerably less energy to heat it. In the summer the layer of air keeps the inner house cool. Complex technical equipment with ever more expensive running costs for maintenance, repairs and replacement is not necessary. It has extremely low energy requirements for heating, and hot water is provided largely independent of rising energy costs, because it takes warmth from the sun free of charge and supplies any additional heat requirements sustainably from wood at a very low price.

The Bio-Solar-House is a healthy, economic and trouble-free house.

Bio-Passive House

A Bio-Solar-House is a new, efficient, biological generation of passive house: A Bio-Passive House, less expensive, energy saving, cost saving, uncomplicated, healthier, more user friendly, more eco-friendly, and future-proof.

Solar EnergyIt is a next generation more efficient improved version of the passive house. It is engineered technically as an energy efficient “house built as a solar energy collector“. It has a natural, healthy living atmosphere without a ventilation system. It has a health promoting radiant heating system. It excludes the risk of dampness and mould by its construction without any technical appliances necessary to achieve this.Ventilation systems are costly and potentially harmful It has a durable biological building fabric and it requires no short-lived cost-intensive technology in the house. It covers its very low heating costs renewably at lowest possible costs, and it has the highest sustainable energy efficiency. It is CO2 neutral. No artificial ventilation, and yet has healthy air quality. Economically it is a money-saving house and not a costly technology house, and receives the highest state support (in Germany). It is based on the proven and patented „Bio-Solar-House” Building- and Energy-System, it stands out as a “Bio-Solar-House” and as “the healthiest house”, it is certified as “Bio-Solar-House” with the “Energy- Plus-logo”.


Treat yourself to radiant heating similar to the sun, with solar energy and wood.

Every house, including every energy saving house, needs heating. Loss of heat through the cladding, the ventilation and through the behaviour of the occupants is unavoidable and must be balanced out. Moreover every house needs to produce hot tap water, for example for showering and washing hands. A house with snug living features without a heating system does not exist!

Bio-Solar-Houses make use of the free solar radiation for heating water. Any solar collector transfers solar energy to a large hot water tank. If during the winter time the solar heating system does not provide enough energy, a wood-burning oven or any other hot-water device will produce the necessary energy for the hot-water tank. This tank has a built-in heat exchanger which heats up the water for domestic use. This is why any contamination of the water with bacteria (e.g. legionella) is impossible.

Hot water runs through thre walls, creating central radiant heatingBio-Solar-Houses have a very efficient, simple and above all healthy system of heat distribution: radiant panel heating. It is supplied with hot water from the hot water tank and provides the occupiers with warmth in the same healthy and pleasant way as the sun does with its radiation. Thermostats control the temperature in each room individually. This type of heating produces no air currents like underfloor heating, radiators or heating installations based on air circulation – these heating systems produce air streams and therefore fill the air you breathe with dust particles.

The whole system is very economical with regard to both acquisition and maintenance. It is conceived in such a way that the number of parts which are affected by continuous wear and tear, and therefore need regular replacing, has been reduced to a minimum. Detached Bio-Solar-Houses have an energy consumption of 15 – 25 kWh/m² on average per year for heating, hot water and open fire, including partial heating of the conservatory.

Wood is used as a an alternative to solarIf the price of a cubic metre of stacked wood is about €80, heating energy costs would be between €150 and €300 per year.1 In the future, prices for firewood and wood pellets will stay relatively stable as opposed to the continuously rising prices of natural gas and electricity. Owners of Bio-Solar-Houses will therefore have no difficulty in paying their low energy bills in the future.


Bio-Solar-Houses are recognised as the healthiest houses

As no artificially produced atmosphere or dust swirling ventilation systems are necessary, the occupants live in a natural healthy climate with low relative humidity, clean air to breathe, and dry walls. Mould growth is physically ruled out and there are also no dust mites. Also viruses, bacteria, allergens and other pollutants which the heating and ventilation systems can harbour are equally excluded, as are disturbing circulation noises. A wall radiant heater warms the occupants as if by rays of the sun and is conducive to their health.

Persons suffering from allergies feel well in this natural climate

In the Bio-Solar-House there are no health hazards “coming from the house.” Health hazards do not have to be combated by expensive technical equipment as in many other low energy or passive houses.

The greatest danger for all buildings and their occupants stems from vapour condensing, thus causing damp conditions and leading in turn to extremely dangerous mould. Allergens, legionella, mite droppings, bacteria and viruses in the air thrive under such conditions and considerably damage the health of the occupants.

Because of its revolutionary building system the Bio-Solar-House has succeeded in preventing these dangers from arising. The steam escapes quite naturally through steam diffusion open house cladding. In contrast with other energy saving houses, where ventilation equipment for the avoidance of condensation is necessary with all the maintenance and extra energy use, as well as the subsequent care and costs for protection from harmful side-effects,all this is rendered superfluous in a Bio-Solar-House.

You therefore have, in contrast to artificially ventilated houses, a natural healthy atmosphere to live in. Its health-promoting effect is further augmented by the organic, non-toxic building materials used and by the wall heating similar to sun rays.

Hence there is in the natural atmosphere of the Bio-Solar-Houses only clean and healthy air to breathe. The Bio-Solar-House has been distinguished by a specialist jury as “the most healthy house in Germany”.

The Bio-Solar-House is the most energy efficient house

Efficiency is the measure for sustainable economic action – but it must be done correctly

The primary energy requirement takes into account more than just end-user consumption. Alongside the energy requirements for heating and hot water, this measure also takes into account losses incurred by energy suppliers during production, its preparation and transport, and also energy loss due to the heating equipment at the consumer end. Bio-Solar-Houses require neither oil, gas, nor electricity for heating. They use almost exclusively renewable energy sources such as sun and wood for heating and hot water.

Since solar energy does not cost much to produce, wood is a locally available and renewable fuel, and the heating equipment has virtually no energy loss, Bio-Solar-Houses have an extremely low primary energy requirement. When comparing the energy consumption of houses it does not therefore depend on their low heating energy requirements, but rather on their low primary energy requirements. This is at one and the same time a measure for their energy efficiency and their environmental protection.

The most important at a glance:

Width, Length, Height: Optional
Attic height: Optional
Slope of roof: Optional
Room height: 2.50m – 2.85m
Supporting structure: Steel or Wood
Cellar: possible
Foundation: Concrete
Number of floors: Optional
Roof shape: Saddle-, Hip-, Lean-to- or arched roof
Roof covering: Partly transparent, otherwise optional
Main wall building material: Untreated wood
Outer wall finishing: optional, e.g. wood, render, plate …
Windows: Optional materials; UG = 0.9 W/m²K
Conservatory glazing: Optional materials; UG = 1.1 W/m²K
Insulation: Cellulose
U-values: Outer walls to air space 0.19 W/m²K; Outer walls incl. airspace and outer cladding 0.09 W/m²K; Top floor ceiling 0.12 W/m²K; Floor 0.19 W/m²K
Inner wall dressing: Optional e.g. Plasterboard, Plaster mould, Wood …
Floor covering: Optional e.g. Tiles, Parquet, Linoleum …
Heating: Wood stove hot water preparation in the conservatory, Electric heating element. Alternative: Pellet stove, approx. 1000 liters thermal store, radiant wall heating controllable room by room ,solar heating system for hot water preparation and heating support
Heating energy requirement: ~ 25 kWh/m²a normally
Primary energy use: ~ 10 kWh/m²a normally
Environmental protection: CO2-neutral, non-toxic building materials


  1. These prices and annual costs have been calculated based on values drawn from the market in Germany.