The efficiency of a Passivhaus relies upon a reduction of all unnecessary junctions – essentially, a box layout is the most conducive to achieving the standard. This obviously places limitations upon the design of the superstructure. A key characteristic of a Passivhaus is its ability to run from passive solar gain, so the fenestration needs to be carefully thought out, to enable the house to gain enough sunlight to warm it, but not too much that will overheat the building.
The path of the sun might influence the entire layout of the house, and to this end, the orientation of the plot needs to be taken into account. Elements that prevent overheating, like shutters or overhangs, may have to be integral to the building design, depending upon these factors. An MVHR system is essential to ensure air is kept fresh and circulated. The placement of these systems must be carefully thought out, bearing in mind that these systems can make noise, and that the interface between the MHVR and the kitchen extract system is critical. The Passivhaus Planning Package (PHPP) is an essential tool for designers; it will check that the designed property will not overheat once in service.
There are obvious benefits to designing to the Passivhaus Standard. As the push for carbon neutrality increases, so too will the demand for efficient homes. Low running cost is also a major benefit of the design, as the investment made initially (into premium insulation and glazing) will be more than earned back.