Energy consumption expenses vary according to building construction and maintenance.
Bioclimatic Architecture can be defined as the development and creation of buildings which take into account the renewable resources throughout the creative process, the project in itself, as well as the construction, operation and management. These buildings adapt to the local environmental conditions, are energy efficient and favour indoor thermal comfort with reduced energy consumption.
Energy efficient buildings or constructions can be defined as those which are developed and designed to allow for a significant reduction in energy consumption for thermal comfort, cooling or heating, regardless of the energy or equipment established for acclimatization.
Energy efficiency can be achieved through various ways: with the above quoted bioclimatic architecture: design, orientation of the building, solar protection and passive solar systems: use of high performance materials in the construction such as insulation, use of thermal glass and windows as well as the use of equipment for thermal comfort and creation of, preferably, renewable energy.
Amongst the existing strategies, we believe the most interesting and cohesive ones are those which are firstly concerned with reducing energy consumption avoiding any waste and implement measures to reduce consumption, secondly seek to use renewable resources in the most efficient way possible.
Based on these assumptions and the aim to increase energy efficiency, which allows for reduced energy consumption, the project of the building is extremely important as it must take into account the climate and surrounding environmental conditions for better use of light and solar heat in addition to all other environmental factors which provide greater comfort.
That said, the project must follow certain principles according to the intended programme. Orientation of the buildings should be as convenient as possible, passive solar systems should also be incorporated as they do not take up energy and make the most out of the surrounding weather conditions, controlling solar radiation, whilst benefitting from the thermal inertia of the building. A proper thermal insulation, that minimizes the thermal exchange between the exterior and interior, of the building envelope and the construction itself including walls, pavements and coverings, a conscious choice of glazed surfaces and size, favouring double glazing and frames with an improved thermal performance as well as proper shading (i.e. shutters, flaps, doors) are all important for a decent and proper working passive solar system. Even the choice of colour for the house paintwork is important, as lighter shades reflect the natural light, reducing heating of the walls and the need for artificial lighting whenever the natural daylight can still be used. All of these factors provide indoor comfort and increase energy efficiency.
Vegetation suggested for outdoor areas is another element to have in mind as proper coverage and foliage can, during the summer, protect glazed surfaces against direct solar radiation and cool the surrounding environment. In the winter they have the opposite effect as direct solar radiation increases indoor thermal comfort.
The above mentioned strategies do not always guarantee the desired efficiency in all situations in which case it is necessary to resort to other equipment, which can benefit from renewable resources, to control thermal levels and avoid lowering energy efficiency.
A building which has been designed according to these principles may seem more costly to start off with but will undoubtedly prove to be advantageous in the long run. Greater energy efficiency does not require the common need to frequently resort to heating or cooling devices which increase energy consumption. The above mentioned energy will, whenever possible, stem from renewable resources through the use of solar panels and so forth.
Regarding the legislative evolution of thermal behaviour of buildings, the Regulations on Thermal Behaviour of Buildings (RCCTE) imposed, in 1990, several requirements to safeguard client satisfaction of the measures of thermal comfort without the need for excessive use of energy in the winter or summer as well as to minimize the pathological effects on the building caused by surface or internal condensation. This diploma was revised in 2006 and adapted to the current social and economic context in addition to the available energy resources of the country, promoting added thermal quality to the buildings.
Thermal devices are also regulated according to the Regulations on HVAC Systems in Buildings (RSECE). The last revision of this diploma dates back to 2006 and has four objectives out of which we have chosen to highlight two, the establishment of measures for thermal comfort and hygiene in the different areas of the buildings according to their uses and the improvement of overall energy efficiency of the buildings.
References:
ecocasa.pt
www.isover.com
Decree-Lawi nº79/2006, Decree-Law nº80/2006
