Energy efficiency and reduced consumption, as a ‘must’ for new buildings and as an engine for the requalification of existing buildings, are imperative synonymous of three basic qualities: environmental ethics, living comfort, cost savings.
The buildings today require many specializations. Given the complexity of the designs and achievements, it is necessary to coordinate the designers, in order to integrate the various specializations.
Should be avoided to do as in the past, when the technicians took turns in the construction site at subsequent times, uninformed of other people’s work, instead they must intersect fruitfully, cooperating in the drafting of a complete and comprehensive project.
low energy buildings design
The search for energy efficiency does not impose bare and strict architectural solutions, but can suggest effective stylish choices that perfectly meet the criteria of low power design.
This global way of thinking materialises with: the choice of materials through which to get a good protection from the weather outside, the organization of transparent surfaces more suited to the exploitation of winter "heat inputs free of charge", the study of shading measures to prevent summer overheating and the possible adoption of a mechanical ventilation system with heat recovery removable from the exhaust air.
Not less important than a scrupulous executive design is the accurate supervision of all stages of the construction site, in order to ensure the real connection between design and existing buildings. The instrument checks (thermography, transmittance analysis with heat flow metres, blower door test, etc.) can be invaluable during and after the construction to ensure the achievement of project objectives, to ratify the proper implementation, to locate executive unexpected errors or technical hitches and remedy.
Instrumental Survey
Non invasive instrumental investigations are valuable to check any architectural problems (water seepages, condensation, air tightness of the building envelope, etc.) on existing buildings, during and at the end of any construction site. The satisfaction of someof these tests is mandatory for specific rewards or certifications of energy (as in the case of those issued by ClimaHaus or by Passiv Haus Institut).
Geology and Environment
Geology, geological report, geologist are increasingly recurrent terms and increasingly used in building practice and even beyond. The knowledge of what surrounds us is essential to understanding and better integrating into the surrounding environment with what we ask or would ask to achieve.
The geologist attempts to answer the question "what lies beneath" (where ‘beneath’ obviously means the underground), to know what you can expect from that level site or that side.
The recent seismic events (earthquakes of 20th and 29th May 2012) that affected Emilia Romagna have showed a huge deficit of knowledge and answers for those who have built.
For this reason, the geological report is always important: the geologist must be able to tell what kind of problems there may be in a site, what can be expected from that plot, how can you defend or which strategies can be adopted to mitigate the potential risks, integrating and relating with all the participants that form a project.
Energy Certification
n 2005, on the transposition of Directive 2002/91/EC on the energy performance of buildings, with the Legislative Decree 192, first piece of legislation in Italy in which is spoken about "building-plant system", is introduced the obligation of energy certification of buildings. It only becomes a reality in 2009 with the publication of the decree ‘national guidelines for energy certification of buildings’, entered into force on July 25th of the same year.
The concept of energy certification is fairly varied and depends on the technical protocol which is referred to.
The national certification protocol, nowadays mandatory in our country for all properties subject to upon payment transfer, refers to the legislation UNI TS 11300’s algorithms.
There are other calculation protocolsthat can be voluntarily chosen by designers to demonstrate the technical quality of a property.
The ClimaHaus protocol (www.agenziacasaclima.it) (mandatory only in the Autonomous Province of Bolzano) or the Passiv Haus protocol (www.passiv.de) are two examples.
E2 Project has designed and supervised the construction of various buildings in the above mentioned standards.
Plant design and automation
The plant design must be an advanced but moderate "integration", which provides for that little bit of energy that the building envelope is not able to accumulate and passively store. Under a design actually "integrated", the technological plant systems must harmoniously interact with the architectural union, according to the morphology of the building and site.
To plant systems is required not only to integrate passive building technologies, but also to act as "active sensors" (think, for example, thermal solar and photovoltaic). In conclusion, they will be the shrewd "managers" of the energy resources of a building, and their good conception, design, execution will contribute decisively to the hygro-climatic benefit even clearly economic, that the end users will appreciate.
Solar analysis and shading
The solar radiation control incident on the building envelope is essential to contain the expenditure of energy related to the summer air conditioning. The uncontrolled entry of solar radiation causes surface overheating (and hence air volumes) in indoor rooms. The combination of this effect with that of the direct radiative exchange between surfaces and occupants, creates conditions of thermal discomfort that aggravate the discomfort already caused by the excessive heat input.
The solar analysis is technically accomplished on a virtual three-dimensional model of the aim of the study. On the same lines of an "integrated design", its first purpose is to suggest to the designer technical and architectural aids best suited to optimize free solar gains during the winter months and to shade the glass surfaces during the summer. Protect yourself from the sun that penetrates in July through a large window facing south is partially possible through technical parameters relating to glass (low solar influence or g factor), but definitely more effective providing architectural shielding, which are an opportunity for a peculiar morphological action of the building in question.
Analysis of construction joints thermal bridges
The thermal bridge may be defined as an area of the building envelope (a physical point or a linear section) which has a thermal behaviour clearly different than that of the surrounding areas, with reference to the distribution of the temperatures and to the propagation of heat.
The mandatory standards requiring the "correction" of thermal bridges, for all new buildings and for retrofitting interventions. The widespread malpractice in construction industry, in the presence of thermal bridges, is instead to simply provide a greater amount of heat.
The damage done by thermal bridges, in addition to a greater dispersion of heat, is certainly in the reduction of thermal comfort. This necessarily happens when, for some portions of the building envelope, surface temperatures of at least 3°C lower than indoor air temperature are observed. But, even more, the presence of spots in which the surface temperature of a wall or a floor considerably varies with compared to the surrounding area facilitates the risk of surface and interstitial condensation, then creates moulds, and consequently the rooms' unhealthiness and an early impoverishment of materials and construction elements.
Strictly avoid thermal bridges is the only design and construction approach permissible today.
At the construction joints, the risk is obviously higher, so is a good idea to study the hygrothermal behaviour of the suspected critical spots.
Energy audits
"...an energy audit of the building and of the plant in which you identify interventions to reduce energy expenditure, the times for their investment return, and the possible class improvements in the building energy certification system in force, and depending on which they were established the installation plant choices that are going to be realized" is the definition offered by Annex 1 of Legislative Decree 311/2006.
What are the real benefits of this survey? The Energy Certificate proposes plausible improvements to the building in question. The main difference is in the degree of detail of the investigation, of the reconstruction of the real utilities of the building, of the balance of costs and benefits of each ameliorative case, so as to ensure the effective realization, by the user, of the energy characteristics of the building, its problems, and its potential.
Therefore it becomes an indispensable planning vehicle of restoration and enhancement of a property, or even just a precious detector of reducible operating costs, if interventions for redevelopment are not provided, with the consequent increase of property's market value.