How to design a bioclimatic facade
In this post about The design of bioclimatic facadesof houses, single-family, buildings or any built element, wants to focus on energy saving andenergy efficiency of the fronts of the buildings - envelope.
We will comment how the orientation of a given facade influences the use of solar radiation and the energy balance of a home or building and we will provide some strategies to take into account during the design phase that will help reduce and optimize energy demand in each orientation.
If we look at the bioclimatic analysis of a house, for a standard type home located in the northern hemisphere, and specifically within the latitude corresponding to the Iberian Peninsula, the following are recommended guidelines for action and design of the facade of a house:
Depending on the situation and location on the planet, orientation in architecture I could seem confused… How to recognize solar orientation on facade?… We leave the image of an application to orient ourselves in the direction of the sun according to location.
Access to the application here, comes from the article on sunning techniques and practical calculation. (History of orientation in architecture here)
Now we will go into the characteristics and guidelines oforientation of spaces in a house attending to some necessary aspects that we must recognize in the world of bioclimatic architecture orientation, advantages and disadvantages, and its possibilities before the path of the Sun.
North orientation in house facades:
In this kind of facades facing northNormally, the sun does not affect directly, so that it only receives some solar radiation at the first and last minute during the summer months in which the sun makes a greater distance or trajectory.
North facade design strategies:
- Non-habitable areas such as bathrooms, toilets, kitchens, facilities rooms, corridors, distributors or entrances, stairs, etc … will be distributed towards this part of the house.
- Design is required facades with a reduced percentage of openings, with few doors and windows to the outside, to avoid energy losses since they are the areas that present the greatest heating demands in winter.
- Distribution of the house in two areas or spaces, so that the non-habitable areas and the passageways are grouped at the rear facing north.
East orientation in house facades:
For the definition of facade In this orientation, the house receives solar radiation during the first hours of the morning until noon, although in winter this radiation will be much softer, while in summer on the East facing façade It will affect more directly and for a longer time so that is when much more sunlight is provided to rooms with this orientation.
The summer on the east facade It will affect more directly and for a longer time so that is when much more sunlight is provided to rooms with this orientation.
East facade design strategies:
- Areas of use or rooms such as the kitchen area or the day area that take advantage of the morning sunlight will be distributed.
- It is convenient to design some type of porch or element of shading by means of deciduous plant species, which allows taking advantage of the sun in winter and limiting excess radiation in summer. It is a good strategy of protection of the housing envelope on the bioclimatic facade.
- Passive solar protections are recommended in the holes with vertical and non-horizontal slat systems. The reason is that when receiving the angle of solar tilt smaller, if we place horizontal slats the sun would filter through and can disturb or dazzle, which would not be an effective system.
- It is also recommended to reduce the size of the holes so that it is not excessive, in this way we will also avoid having excessive heating demands in winter as well as cooling in summer, although this will also depend on the climatic parameters and the severity of the area climate in which it is located.
South orientation in house facades:
The South facades are of great importance. It is undoubtedly the area of the house that receives the greatest amount of solar radiation, especially in summer, being therefore the main front - front towards which the house must open in its projection and design, since that is where it receives more natural light.
South facade design strategies:
- The rooms where more time is spent and more light is required, such as the main living room or living area, the main bedrooms of the house, etc … will be distributed in the southern area of the same.
- It is desirable that most of the main facade of the house It is oriented towards the south to get the maximum use of the sun, and that in this orientation the facades have more openings than in the rest of the orientations of the house.
- It is recommended to take into account in the design and location of the construction if there are neighboring buildings, nearby buildings or other types of natural obstacles or of another nature that could cast shade on our bioclimatic ventilated facade, since this can condition its location within the plot or plot.
- Special attention must be paid to the design of solar protection such as roof overhangs or eaves, since it is the façade that receives the most sunlight, so an optimal but not excessive flight length must be projected, since in summer the sun affects with a very steep angle, while in winter the sun falls much lower and solar gain must be allowed. The aim is to achieve in each season of the year the adequate use of the amount of solar radiation necessary to improve the energy balance of the rooms with this orientation.
Keep in mind that the bioclimatic analysis of a house It has some significant features compared to traditional houses. From the following image we can see roughly the most notable differences of a construction aimed at sustainability:
West orientation in house facades:
In the west facade. The sun affects mainly from noon, especially in the afternoon, receiving solar radiation from the last hours of the day. The angle of the sun on the facade it decays as the hours go by until sunset.
West facade design strategies:
-It is convenient to have the rooms such as the garage, the services of the rooms facing south, leisure or games areas, etc.
- The gaps in these facades will be arranged in such a way that, together with those that open on the facades facing east, allow adequate cross ventilation for ventilation of the house as well as proper night-time cooling in summer.
- To avoid glare, as in the case of east-facing facades, it is convenient to have passive solar shading on the eggs with vertical and not horizontal slats.
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In the next infographic we can identify the facades of a house and its key points to determine the orientation of spaces in a home:
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Some global strategies according to orientation:
House facade design according to environment:
- Know what is the direction of the prevailing winds in the area where the facade of the house is located, In this way, it will be located and the façade will be designed in such a way that intrusion into the interior should be avoided, as this would contribute to greater energy losses or gains.
If necessary to avoid this effect, plant screens can be designed using trees or vegetation that helps to block said air circulation over the house facade.
- Find an optimal percentage of openings based on the orientation of each facade of the house. Trying that the facades to the south are those that have the highest percentage of openings and those that face the north the least, this will help in a very favorable way to reduce energy demands.
In the following diagram we can distinguish the facades with holes optimal in%.
|
FACADE ORIENTATION |
OPTIMAL% OF HOLES |
|
NORTH |
10-15 % |
|
THIS |
< 20 %. |
|
SOUTH |
40-60 % |
|
WEST |
< 20 %. |
- Incorporate into the design of the house some element in the areas of passage, distributors or corridors, with windows or openings in the upper area or in the roof, which can be opened in summer to promote natural passive ventilation and cooling, especially in areas where summers are hotter.
- Optimal design of the overhangs and eaves on the south facades and choice of suitable solar shading for the openings.A good option would be to use adjustable movable slat shutters, with horizontal slats to the south and vertical slats to the east and west.
For proper application of the design strategies for a facade From the point of view of energy efficiency, it is very important to take into account that each home will require specific strategies such as: The climatic zone in which it is located, characteristics of the local climate, its altitude above sea level, the presence of natural obstacles or buildings that can alter the natural solar contribution or the circulation and direction of the prevailing winds, proximity or proximity to the sea, etc …
In each case, according to these factors, the technician must analyze and assess which are the most appropriate strategies.
To increase knowledge, it is advisable to see the construction techniques of bioclimatic facades in the article how to build bioclimatic houses where 38 high-value chips are shown.
The perfect example
It is evident that the location of the house within the plot It will be the one that determines the characteristics of our home in its envelope and its energy efficiency.
Not all buildings have so many possibilities and some even have a facade against the Sun, but we wanted to find a example of orientation in housing So that we realize that we are not at odds with either good taste or design when practicing an optimal layout in the house that we are going to live in.
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Points of interest:
- Bioclimatic design manual … HERE.
- The form of architecture encouraged by the wind and the sun … HERE.
- Urban design, more than 30 manuals … HERE.
- Biosustainable or sustainable architecture (22 Documents … HERE)
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Note: A colleague of ours via LinkedIn has suggested us a video… «Geolocate the model to project real sun and shadows on it in Sketchup«. Very practical and worthy of your viewing to be able to obtain real shadows and quickly in the house facades before our projects or the buildings that we can locate.
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