Bioclimatic architecture uses natural elements such as sun, wind, water, soil, and vegetation to create extremely efficient buildings, capable of ensuring significant energy savings through the use of renewable sources.

Analysis of the context and orientation of the building

Sustainable design requires an analysis of the area and its context, so it is essential to:

analyze the site’s climatic and geological factors;
verify the presence of sources of pollution (air, noise, etc.);
analyze the prevailing winds;
analyze the sun’s path and the angle of its rays throughout the year, relative to the latitude of the project.

The purpose of these preventive measures should ensure the right balance between orientation issues and context.

An additional effort will be needed when designing in city centers, where the greater density of buildings creates constraints in every respect: from shape to orientation to size, etc.

Shape and characteristics of the envelope in relation to solar radiation

Once the building is correctly located on the lot, the following must also be considered:

The correct distribution of interior spaces.

Given that there are numerous variables, including the possibility of a block building, a terraced house, etc., and that this will require specific considerations for each case, consider that, generally speaking, with main facades facing north and south, the sleeping area will be on the north side and the main rooms on the south side; with main facades facing east and west, the sleeping area will be on the east side and the main rooms on the west side.

The choice of shape for the building’s envelope.

This choice certainly has a significant impact on the building’s aesthetic appearance; however, from a purely bioclimatic perspective, the envelope could feature balconies, loggias, and large windows on the south side. Why? These openings, taking advantage of the greenhouse effect, a consequence of the properties of glass, will generate a natural increase in the interior temperature in winter. At the same time, this means that, while these openings are efficient for winter heating, in summer they must be equipped with equally efficient shading systems (fixed or mobile awnings, sunshades, etc.), which work in conjunction with suitable vegetation and, together with the latter, ensure cooling. Therefore, the internal layout of the rooms, the configuration of the envelope’s shapes and volumes, the distribution and size of the openings, the shading design, and the possible use of indirect-gain solar systems must be considered.

Examples of indirect gain solar systems

• The thermal wall: south-facing and protected by glass, it accumulates heat that is released to the wall by conduction and released into the interior by radiation or convection;
  The Trombe wall: functions like the thermal wall, but has a dark south-facing wall and, through openings at the top and bottom of the wall, connected to the interior spaces, allows for natural thermal circulation of hot air;
  The Barra-Costantini system (an evolution of the Trombe wall): a dark metal plate is inserted between the wall and the glass and acts as a solar collector;
  The “solar well” system: a glass collector emerges from the building’s roof, via a dedicated structure, the “solar well.” Inside the solar well, the greenhouse effect occurs, with heat being transmitted by conduction to the wall separating the “well” from the living space;
  Solar greenhouses: there are various types and they aim to accumulate solar energy through specific greenhouse environments located to the south of the building (see attached greenhouses with thermal wall accumulation, with rock-bed-wall system, with rock-bed system, with transparent dividing wall, etc.)

Infill walls for sustainable design

Environmental comfort also depends on the choice of materials used for the infill walls (perimeter walls) and their construction. Indeed, they must have the following characteristics:

High thermal resistance, i.e., insulation obtained with panels facing outward;
High thermal inertia, i.e., the ability to attenuate temperature fluctuations inside the building that occur outside;
Minimum thermal bridges;
Good acoustic insulation.

The infill walls can therefore be constructed:

with traditional systems (e.g., external insulation);
with transparent or opaque panels, connected by a metal structure;
with a curtain wall;
with a ventilated wall, a multilayer wall, which addresses energy efficiency issues very well.

This wall is characterized by a stratification that, when viewed from the inside out, appears as follows:

internal wall
vapor barrier
continuous insulation layer on the external face
ventilation cavity
supporting structure of the external cladding
external cladding

Green walls as infill for sustainable design

The advantage of green walls is that they can function very well not only aesthetically, but also bioclimatically.

Greenery as a cladding is undoubtedly one of the strategies that lends itself well to improving environmental quality in both cities and rural areas, and we can distinguish three main groups:

Green facades: climbing vegetation growing from the ground on a trellis at the base of the facade;
Vertical gardens: vegetation growing in tubs anchored to the wall and irrigated with systems spaced from the wall;
Living walls: pre-vegetated modules made of inorganic material, mounted on the facade and fed by fertigation processes.

Although these technologies are expensive to build and maintain and require energy for automatic irrigation, local regulations often encourage their use, given their proven beneficial effects on the area’s microclimate, the shading they provide, and the protection from pollutants they provide.

Roofs for Sustainable Design

Moving on to green roofs, they are also an increasingly popular solution, given their positive effects on the microclimate and water management, thermal and acoustic insulation, reduced polluting emissions, and aesthetic advantages.

They can be divided into two types:

Extensive green roofs, with a thickness between 8 and 15 cm and a layering that generally unfolds above the roof structure as follows:
Vapor barrier
Thermal insulation
Waterproofing layer
Root barrier layer
Drainage elements with water reservoir
Filter layer
Growing soil with perimeter drainage

The type of vegetation chosen will depend on the building’s geolocation.

Intensive green roofs, with a deeper layer between 15 cm and 1 meter, and which includes the addition of shrubs, vegetables, and medium-height shrubs. In this case, therefore, a real walkable garden is created, which will also require any adaptation of the underlying structure.

Fixtures and openings

Openings are another critical aspect of a building’s thermal and acoustic insulation.

Windows can be made of wood, metal materials such as aluminum, steel, and thermally insulated PVC, or a combination of both.

The choice of material will obviously affect not only the building’s performance but also the aesthetic appearance of the envelope and, consequently, the interiors.

Photovoltaic Panels

Electricity generation is possible thanks to photovoltaic panels, which exploit the properties of silicon (from which they are made) to transform solar radiation into continuous electrical energy. For best performance, in Italy, panels should be positioned facing south, tilted approximately 30 degrees—specifically, 35° in Milan, 32.6° in Rome, and 29.28° in Syracuse.

Note that for electricity generation, there are different types of photovoltaic panels, with varying characteristics and performance: monocrystalline and polycrystalline panels, amorphous thin-film panels, and building-integrated panels (BiPV technology, an acronym for Building Integrated Photovoltaics).

As for photovoltaic panels for domestic hot water production, they can be natural circulation or forced circulation. The latter, more efficient than the former, have internal tubes through which water and antifreeze flow, heating up when exposed to the sun. When the liquid in the control unit reaches a higher temperature than the water in the tank, the control unit activates the pump that pushes the liquid through the circuit, passing it through a coil into the tank. It is through this coil that the heat from the liquid is transferred to the water in the tank.

In this case, too, the panels are tilted at approximately 30 degrees, and it should be noted that, at present, it is not yet possible to heat a home 100% with photovoltaic systems, so a condensing boiler will be required.

Wind turbines

These are technological systems that transform the kinetic energy of the wind into electrical energy.
They consist of a turbine, composed of a generator and blades that generate rotation, thanks to the wind speed.

This type of system is also known as a mini-wind turbine, which is small and easy to install, making it ideal for installation in existing private and commercial buildings.

Hydroelectric Plants

These are systems that use water to generate electricity, and are therefore found in areas with large bodies of water. A hydraulic turbine, driven by the movement of the water, causes rotation, which generates electricity.

The power of a hydroelectric plant is determined by:

The volume of water moved, or flow rate;

The difference in elevation between the level from which the water is drawn and the level to which it is returned.

Geothermal Energy

We conclude this long list of possible options with a brief mention of a type of system that is rarely used in Italy. They harness the energy of the earth, but are more widespread in Northern Europe and the United States. Geothermal systems not only produce hot water for winter heating and sanitary purposes, but also cold water for cooling in summer.

In conclusion, bioclimatic and sustainable design is closer than we might imagine to pre-Industrial Revolution design.

The speed of technology has led us to believe we possess infinite resources, but it only took a few years to realize the need to repair the damage done by this false belief. This is why bioclimatic architecture is increasingly discussed, and why it is so important and so interesting. It begins with conscious design, which analyzes the context in which it is located and views natural elements as the primary allies of good architecture.

Inside Project consultancy

Our firm offers qualified and expert consultancy in various fields related to bioclimatic architecture, energy certifications, environmental design, and sustainable architecture. Our headquarters are in Vigasio, in the province of Verona, and our clients are both private individuals and businesses. We operate both locally and nationally, providing consultancy to some of Italy’s leading construction companies.