Bio Solar House – THE Passiv Haus alternative?

Example 6
An example of a Bio Solar Haus

In the UK we have a couple of recognised building standards: Code for Sustainable Homes and Passive House (Passiv Haus). CSH is based on SAP and a range of other factors, but this will soon be phased out and replaced by Building Regulations. This will then focus on energy usage. Passive Houses use PHPP to calculate how the building will perform, and again it is focused on energy use. PHPP is much more accurate than SAP, but there is an element missing in both because of the focus on energy use. That is what it is like to live in it.

In Germany an engineer called Klaus Becher decided that he wanted to build a low energy house that did not rely on mechanics and electronics to work efficiently. As he puts it:

‘nature offers the simplest and cheapest solution to all problems. I wanted to build myself a retirement home, that would keep me healthy, required little technology, used little energy, was easy to maintain, protected the environment, liberated me from constantly rising running costs, gave me my desired space and was affordable.’

So using his engineering background he set about designing and building a house. So what he has come up with is an ingenious solution of a House in a House. This means that the structure uses nature to drive the heating and venting of the house by the means of an internal ‘Winter Garden’ that collects solar gain, which in turn expands the air in it and uses this pressure differential to push the warmed air through the building. Summer cooling is provided by using air passed through ducts in the ground. Heating is generated by solar collection as well and then disseminated by a wall heating system. If additional heating is required (on those cold dull days, then a small biomass boiler is used to drive the system).

To top the environmental credentials the designs are based on using wood as the main source of material. So the whole house becomes a carbon sink as well.

A Holzhaus (Wood House) from Bio Solar Haus

In the UK, these houses only come in kit form, but you can have almost any shape or configuration, depending on your design needs and sensitivities. The main external house is the main frame of the building and the internal house is then designed to be a flexible space, so the house can be altered to your changing needs. Marvellous.

So if you are looking to build your own home it is worth remembering that there is an alternative to Passive House that won’t have you fretting about MVHR’s, automatic shades etc.

More info can be found at for the English site and for the German. Holzhaus info in German can be found at