Reducing the cost of building a Passive House


Reducing Costs and Protecting the Environment

As the energy demands of a passive house are reduced by up to 90% - heating costs and therefore CO2 emissions are reduced drastically when compared to a conventionally constructed building.  On average around 4,000kg of greenhouse relevant carbon monoxide are avoided each year by achieving Passiv Haus standards.

This would correspond to driving about 15,218km with a typical 1.8 litre car.  Therefore constructing energy efficient passive houses supports climate protection sustainably and saves on limited resources such as oil or gas.

One of the major characteristics of passive houses is the active utilisation of existing energy, this is achieved through the minimisation of thermal losses combined with "time optimising" thermal gains. To achieve this careful selection of building materials and parts is made early on in the design process.  However merely combining passive house certified components is not enough to reach a passive house construction standard: The whole building is required to become more than the sum of its parts.  Each component must be carefully checked to ensure that interactions between the distinct components fulfil three basic demands:

  • Heating demand: < 15 kWh/m2a
  • Primary energy demand: (heating, warm water, house appliances) < 120 kWh/(m2a)
  • Pressure difference demand: air exchange n50 < 0.6 h-1 (i.e. at a pressure difference of 50 Pascal the air flow must be less than 60 % the building's volume per hour.)

A typical system designed to achieve these demands would involve the passive house being constructed with an impermeable outside shell and optimised thermal insulation combined with integrated ventilation in both directions. Fresh air is sucked into the building underground through the ventilation pipe, pre-heated by the earth, and led to the heat recovery system. There the energy of the used air is passed on to the fresh, filtered, cold air using a heat exchanger. Here the energy stored in used air, which would normally be lost in traditional airing, is utilised. Next the air is led into the living areas and distributed with special nozzles in order to avoid draughts. To complete the system air is removed from the sanitary areas and the kitchen, in order to avoid the spread of unpleasant smells throughout the house.

Passive House Certified Windows & Doors

Internorm is number one manufacturer globally in the design and construction of passive house windows and currently the only window manufacturer in Europe with nine passive house components certified by the Passivhaus institute founded by Dr. Wolfgang Feist".  These components are used in all Internorm window and door systems.

Basic Tips for Passive House Building to Passivhaus institute Standards

  • Good thermal protection of the facade through appropriate insulation (U < 0.15 W/m2K).
  • Super glazing and super window frames.  Typically with U values < 0.80 W/m2K and g value around 50%.
  • Avoid the use of thermal bridges.
  • South facing of large windows to use the sun as source of energy.
  • Passive pre-warming of fresh air which can be achieved through use of a earth heat exchanger.
  • Heat recovery from used air through counter flow heat exchanger.
  • Water heating possible through renewable energies.
  • Energy saving appliances throughout the household.