INTRODUCTION OF PASSIVE DESIGN ⋆ Archi-Monarch

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Passive design refers to a set of architectural and building design principles that aim to optimize the use of natural resources, such as sunlight, wind, and thermal mass, to reduce the need for mechanical heating, cooling, and lighting. The goal of passive design is to create comfortable and energy-efficient indoor environments that minimize the building’s impact on the environment.

‘Passive design’ is design that takes advantage of the climate to maintain a comfortable temperature range in the home.

Passive design reduces or eliminates the need for auxiliary heating or cooling, which accounts for about 40% (or much more in some climates) of energy use in the average home.

To increase the energy efficiency of a building, a variety of active and passive design strategies can be incorporated.
Active strategies usually consist of heating and cooling systems, while passive design measures include building orientation, air sealing, continuous insulation, windows and daylighting, and designing a building to take advantage of natural ventilation opportunities.

1) Climate

Good passive design ensures that the occupants remain thermally comfortable with minimal auxiliary heating or cooling in the climate where they are built.
Identifying your own climate zone and gaining an understanding of the principles of thermal comfort helps you make informed design choices for your home.

2) Orientation

Orientation refers to the way you place your home on its site to take advantage of climatic features such as sun and cooling breezes.

For example, in all but tropical climates living areas would ideally face north, or as close to north as possible, allowing maximum exposure to the sun, and easy shading of walls and windows in summer.

Good orientation reduces the need for auxiliary heating and cooling and improves solar access to panels for solar photovoltaics and hot water.
Orientating a building to take advantage of how the sun moves across the sky is the easiest and most effective passive design strategy.

3) Shading

Shading of your house and outdoor spaces reduces summer temperatures, improves comfort and saves energy.
Direct sun can generate the same heat as a single bar radiator over each square metre of a surface.

Effective shading — which can include eaves, window awnings, shutters, pergolas and plantings — can block up to 90% of this heat.

Shading of glass to reduce unwanted heat gain is critical, as unprotected glass is often the greatest source of heat gain in a house.
However, poorly designed fixed shading can block winter sun.
By calculating sun angles for your location, and considering climate and house orientation, you can use shading to maximise thermal comfort.

4) Passive solar heating

Passive solar heating is the least expensive way to heat your home.

Put simply, design for passive solar heating keeps out summer sun and lets in winter sun while ensuring that the building envelope keeps that heat inside in winter and allows any built up heat to escape in summer.
Orientation, thermal mass, sealing and other elements all contribute to the design of a house that benefits from passive solar heating.

5) Passive cooling

Passive cooling is the least expensive way to cool your home.

To be effective, passive cooling techniques need to cool both the house and the people in it — with elements such as air movement, evaporative cooling and thermal mass.
Passive cooling design techniques can be applied to new homes as well as renovations, across a range of different climate zones.

6) Sealing your home

Air leakage accounts for 15–25% of winter heat loss in buildings and can contribute to significant loss of ‘coolth’ in climates where air conditioners are used.
Sealing your home against air leaks is one of the simplest upgrades you can undertake to increase your comfort while reducing energy bills and greenhouse gas emissions.
The more extreme your climate, the more beneficial sealing is, with the exception of naturally ventilated homes in the tropics.
As sealing your home and increasing insulation levels can also create condensation and indoor air quality problems, this article explains how condensation works, which climates present the greatest condensation risk and how you can limit its impact.

7) Insulation

Insulation is particularly important for buildings in colder climates. “Insulation helps the building envelope to resist the conductive flow of heat, and it is typically most effective when installed as continuous insulation
Insulation acts as a barrier to heat flow and is essential for keeping your home warm in winter and cool in summer.
It can also help with weatherproofing and soundproofing.
A well-insulated and well-designed home provides year-round comfort, cutting cooling and heating bills by up to half and reducing greenhouse gas emissions.
Climatic conditions determine the appropriate level of insulation as well as the most appropriate type to choose — bulk, reflective or composite.
The most economical time to install insulation is during construction.

8) Insulation installation

If insulation is to perform as intended then it must be correctly installed.

For example, if bulk insulation is compressed, so are the air pockets within it that provide the insulation and it doesn’t work effectively; neither does foil insulation if it is installed without an adjacent air gap.

9) Thermal mass

Thermal mass is the ability of a material to absorb and store heat energy.
A lot of heat energy is needed to change the temperature of high density materials such as concrete, bricks and tiles: these materials have high heat storage capacity and are therefore said to have high thermal mass.
Lightweight materials such as timber have low thermal mass.

Use of materials with high thermal mass throughout your home can save significantly on heating and cooling bills, but thermal mass must be used appropriately.

10) Glazing

Glazed windows and doors bring in light and fresh air and offer views that connect interior living spaces with the outdoors.

However, they can be a major source of unwanted heat gain in summer and heat loss in winter. Up to 40% of a home’s heating energy can be lost and up to 87% of its heat gained through glazing.

These thermal performance problems can be largely overcome by selecting the right glazing systems for your orientation and climate, and considering the size and location of window openings in your design.

11) Skylights

Skylights can make a major contribution to energy efficiency and comfort.

They are an excellent source of natural light, perhaps admitting more than three times as much light as a vertical window of the same size, and can improve natural ventilation.

However, they can be a major source of unwanted heat gain in summer and heat loss in winter.

Factors to be considered when selecting from the many skylight options available include sizing and spacing (to control glare and heat gain), energy efficiency and appropriateness for climate.

Passive design principles can be applied to all types of buildings, from residential to commercial, and can result in significant energy savings and reduced carbon emissions. Passive design is often integrated with other sustainable design practices such as green roofs, rainwater harvesting, and renewable energy systems to create high-performance, low-impact buildings.