Eco houses, low-energy houses… call them what you will, they’re buildings that use very little energy to heat and cool. If they meet a very rigorous set of standards, they can be certified as a Passivhaus building.
All the properties we work on are low-energy buildings and several have full Passivhaus certification.
A typical low-energy building will be highly airtight, very well insulated and use a mechanical ventilation and heat recovery (MHRV) system. Together, these features reduce the amount of energy needed to maintain a comfortable temperature and regulate moisture all year round.
How? Because they work as a system to:
- eliminate draughts that make you feel colder
- stop warm air escaping from your building in winter, and prevent warm air coming in from outside in summer
- capture heat generated by appliances and occupants inside the building, redistributing it in winter or expelling it in summer to maintain the internal temperature you want
- capture and regulate moisture created in the building, to prevent condensation
About the Passivhaus standard
Passivhaus is the leading international standard for low-energy design.
Over 37,000 buildings have been designed, built and tested to this standard worldwide, including several that have been built using our frames at their heart.
Benefits: why build this way?
How to achieve Passivhaus standard
- very high levels of insulation
- extremely high performance windows with insulated frames
- airtight building fabric
- ‘thermal bridge free’ construction
- a mechanical ventilation system with highly efficient heat recovery
- accurate design using the Passive House Planning Package (PHPP)
Passivhaus performance targets *
- Primary energy demand: ≤ 120 kWh/m2. yr
- Space heating demand: ≤ 15 kWh/m2. yr
- Space cooling demand: ≤ 15 kWh/m2. yr
- Specific cooling load: ≤ 10 W/m2
- Airtightness: ≤ 0.6 air changes/ hr @ n50
*Source: Passivhaus Trust