A Passive House requires very little energy to maintain a comfortable temperature year-round, making conventional heating and air conditioning systems obsolete.

A Passive House maintains a constant temperature and therefore does not rely on wasteful amounts of fossil fuels to continually heat and cool.

Passivhaus Building
Explained in 90 Seconds

Passive House building is a construction concept. It is a rigorous, voluntary standard for energy efficiency applied during the construction of a building, which reduces its ecological footprint.

Passivhaus buildings have ultra-low energy requirements for space heating or cooling.

The long-term savings on energy bills offered by Passive Homes, coupled with their environmentally friendly credentials, means they make for a great investment.

How Passive House
Buildings WORK

Passive Houses reuse “free” heat to maintain a constant temperature and heat the home. This “free” heat is generated from electrical and gas appliances such ovens, refrigerators, computers and light bulbs.

For a building to be Passive House it must be extremely well insulated and air-tight so that this heat cannot leak out.

To achieve this a 3-step process is followed:

EcoVert Ventilation

A mechanical ventilation system, with an air to air heat recovery component, is installed to simultaneously bring in fresh air and remove the same amount of stale air.

Passive House Ventilation

The stale air leaving the house is carrying the “free” heat. It goes through the heat recovery ventilator, and transfers that heat, to the incoming fresh air, before it leaves the building.

EcoVert Solution Ventilation

The cool, exterior fresh air comes into the heat recovery ventilator, picks up the “free” heat and goes into the home warm.

As this process is so efficient, there is no need for a conventional heating system, and the savings made invested in better insulation, air-tightness, windows, ventilation and a less expensive backup heating system.

Characteristics of a passive house

Passive solar gains

The sun is the primary source of heat for a Passive House. Therefore, where the house is situated on a plot and the size and position of windows are important factors.

High-efficiency windows

Efficient windows are essential to Passive House building. The specific windows used vary from climate to climate, but triple-paned windows with low-e glazing, argon gas and insulated frames are common.

Passive heating technology

Passive Houses have the ability to heat (or cool) the inside spaces with nothing but fresh exterior air. As fresh, cold air enters the house through the ventilation system, it is heated by the warm air it passes on its way out.

Ventilation

An efficient central ventilation system continually exchanges moist, “polluted” inside air for fresh, filtered outside air. This ensures a comfortable, consistent temperature and humidity level.

Airtight construction

Airtight construction techniques to prevent moist room air from penetrating into the home’s construction where it can cause mould, affect inside air quality and even structural damage.

Design without thermal bridges

The heated air inside a house will follow the path of least resistance to the outside. This is known as a “thermal bridge.” These are common in conventional homes, originating from inefficient windows, poorly insulated walls or cracks under doors. But Passive buildings eliminate them through superior insulation and efficient windows and doors.

Heavy insulation

Highly efficient insulation is required that wraps continuously around the building envelope. This even includes beneath the concrete slab in the basement. The result is a reduction in heat transfer between indoor and outdoor spaces.

How Energy Efficient Are
Passive Houses?

The energy efficiency of a house is measured in Kilowatt hours per square foot per year. (KWh / ft² / yr).

A Passivhaus needs just 15 kWh of heating energy per square metre net floor surface per year (15 kWh/m2a). Assuming it’s an average-sized UK home, that’s the equivalent of around £50 worth of gas per year.

A draughty gas-heated Victorian villa would use 300 kWh/m2a and spend £1,000 a year.