PASSIVHAUS
Passivhaus (or Passive House) is a leading international low energy design standard, providing high standards of occupant comfort and health as well as reducing energy use and carbon emissions from buildings in the UK. YARD Architects director Simon Graham is a fully certified Passivhaus designer.
There are a set of rigorous requirements that must be met in order for a building to be considered a Passivhaus. As architects we have a responsibility to consider the impact of what we are building on the environment and we believe it is important to move towards net zero carbon emissions, as the construction industry contributes almost 38% of global carbon emissions.
"A Passivhaus is a building in which thermal comfort can be achieved solely by post-heating or post-cooling the fresh air flow required for a good indoor air quality, without the need for additional re-circulation of air." - Passivhaus Institute (PHI)
Passivhaus Principles - Passivhaus is not a rigid set of regulations applied to new builds, rather a complex evaluation of the impact of design decisions on energy usage. We see one of the main advantages of the Passivhaus approach as one of ‘fabric first’, which relies on good building design and construction detailing to achieve a very low energy home using simple technologies. A Passivhaus is designed to make the most of the free energy from the sun, principally facing south where possible. North facing window are minimised and very high levels of thermal insulation wrap the building. All windows will be triple glazed and openings carefully sized to maximise the energy balance between heat losses and gains. Energy loss is further reduced by achieving very high levels of air tightness. A simple mechanical ventilation system provides constant fresh air into the building, and the heat from exhaust air is reused to heat the incoming air (MVHR). Importantly, Passivhaus also considers overheating and sets limits on the design to restrict this over the summer months.
Passivhaus Benefits - The Passivhaus approach results in buildings which should always be low energy even if current technologies become obsolete whilst also delivering very good levels of air quality, ventilation and resistance to overheating in summer. The internal temperature of the house will stay very consistent throughout the year and energy bills will be very low. A Passivhaus creates a very comfortable and healthy home with low running costs.
Retrofit with Passivhaus components- The Passivhaus standard is aimed at new build houses, but retrofit can also meet low energy standards using ‘EnerPHit standard for refurbishment’. The standards are relaxed slightly from the Passivhaus standards, due to the restraints and complexities existing buildings present, however, there is still vast improvements that can be made. Substantial energy saving is possible to existing buildings when considering the following aspects:
Improved thermal insulation
Minimisation of thermal bridges
Improved airtightness
Use of excellent quality windows
Ventilation with efficient heat recovery
Efficient heat generation
Use of renewable energy sources
