An passive-house, or 'passive house' in Spanish, refers to a standard for home construction that promotes the Energy Efficiency and a low ecological impact. This housing model seeks to reduce energy consumption and maximize comfort by using the bioclimatic architecture and advanced insulation techniques. The Passive House not only guarantees low energy consumption, but also ensures that the home remains in optimal conditions throughout the year, without the need for expensive heating or cooling systems.
Characteristics of a Passive House
- Energy efficiency: Energy consumption is kept to a minimum by harnessing natural energy available in the surroundings, such as sunlight and wind. In addition, the house is designed to reduce heat loss in winter and prevent overheating in summer.
- Thermal comfort: Through proper insulation and bioclimatic design, passive houses maintain a comfortable temperature all year round, without the need for traditional air conditioning systems.
- Air tightness: Passive houses are designed to be highly airtight, preventing the infiltration of unwanted air. This prevents heat loss in winter and hot air in summer.
- Use of mechanical ventilation: This system includes a heat recovery unit that allows the house to be ventilated using the heat from the outgoing air to heat or cool the incoming air, thus minimising energy expenditure.
- Ecological materials: These houses are built with environmentally friendly materials, such as certified wood and recycled or low-environmental-impact insulation, such as wood fiber or cork.
Origin of the Passive House concept
The concept of Passive House did not arise from marketing, but from the need to reduce energy costs in buildings. It was developed in the late 80s by Wolfgang Feist in Germany and Bo Adamson in Sweden. The first passive house was built in Darmstadt, Germany, with the aim of demonstrating that it was economically viable build homes that consume up to 90% less energy compared to traditional constructions.
Passive houses differ from conventional buildings mainly in that they are designed to maximize the use of solar radiation and heat generated internally (by people or appliances), which is complemented by superior thermal insulation. In addition, these homes include mechanical ventilation systems with heat recovery, thus avoiding the energy loss that occurs with natural ventilation systems.
Energy savings in passive houses
One of the main advantages of building and living in a passive-house is its considerable reduction in energy consumption. These houses can consume up to 90% less energy for heating than a traditional home. Even in the case of new buildings with high energy efficiency standards, a passive house can generate savings of 75% or more in the use of heating or cooling systems.
In temperate climates, where the largest expenditure in traditional homes is usually spent on cooling, Passive Houses have also proven to be significantly more efficient. Thanks to the mechanical ventilation with heat recovery and by taking advantage of the shade in summer, a comfortable temperature can be maintained inside without having to consume large amounts of energy.
Advantages of Passive House
- Significant reduction in energy bills: The savings on heating and cooling are significant, which translates into lower energy bills in the long term.
- Better quality of life: Constant monitoring of temperature and ventilation ensures that optimal levels of comfort are maintained inside the house, in terms of temperature and air quality.
- Respect for the environment and sustainability: Passive houses not only save energy during use, but are built with eco-friendly materials that reduce environmental impact from the start.
- Greater durability and low maintenance costs: Because they are made of high-quality materials and modern systems, passive houses require fewer repairs and last longer.
Design and construction of a passive house
Passive houses are characterized by following a very particular design standard, oriented towards energy efficiency. Some of their main characteristics include:
- Superior thermal insulation: They use materials with very low thermal transmittance in walls, ceilings and floors to minimize heat loss in winter and prevent overheating in summer.
- High performance windows and doors: These houses have quality carpentry, designed to prevent heat loss. The windows are usually triple glazed, which significantly improves thermal insulation.
- Avoid thermal bridges: A well-planned design prevents energy leakage. This is achieved by ensuring that there are no weak points in the building envelope.
- Air tightness: This is to prevent unwanted air infiltration, which also helps to maintain a constant temperature inside.
- Controlled mechanical ventilation with heat recovery: This system allows the air inside the home to be renewed without losing the heat inside, minimising energy losses.
Passive House Design Requirements
Apart from its insulation and ventilation, the design of a Passive House is also crucial to maximizing its efficiency. Factors such as the site of housing and the solar orientation are essential to make the most of sunlight for natural heating. South-facing houses, for example, tend to have greater thermal efficiency and require less heating in winter.
In addition, the inclusion of systems that protect from the sun in summer, such as the use of awnings or pergolas, allows homes to stay cool without the excessive use of air conditioning. The architectural design of Passive Houses does not follow a single style; they can be adapted to any type of construction, from single-family homes to office buildings or schools.
Passive houses are a necessary step towards a more sustainable future in building construction. Not only do they help reduce energy costs and minimize environmental impact, but they also improve the quality of life of the people who live in them.