From a purely commercial point of view, the Italian real estate market seems to now understand the concept of the energy certification of buildings.
However, the certificate itself is not sufficient to ensure the comfort and quality of the building. Here’s why:
Case-Study: an ‘Emilia Romagna Class B’ house
Sometimes friends, family or potential clients ask us to give a rough estimate of the quality of a project or a building that they are interested in purchasing.
As such, we’ve been able to visit many construction sites and finished buildings designed by others, ranging from renovations to new construction:
We recently had the opportunity to visit a construction site in the province of Reggio Emilia – climatic zone E – where common building challenges mainly involve the saving of energy through the heating systems.
The project, which dates back to 2008-09 (before the economic crisis here in Italy), involves the construction of eight residential units divided into four duplexes.
The designers wanted to orient the buildings towards the West, showing a preference (perhaps justifiably) for the landscape view than the overall energy efficiency. For maximum energy efficiency, the building should be oriented towards the South.
The real estate agent who accompanied us to the site said that the building will be certified ‘Emilia Romagna Class B’. Do we believe this? Or do we not believe this? Keeping in mind, the building is still under construction, without windows, and without services:
It is NEVER possible to determine the energy class of a building before the work is completed.
One thing you can determine in a site visit before the completion of works, however, is the extent of the errors being made in the thermal envelope. You don’t even need a heat-sensing camera to identify some very serious problems.
A very clear thermal bridge
One of the biggest concerns we’d like to highlight from this case study is this quite evident thermal bridge at an uninsulated, reinforced concrete corner pillar.
Basically a thermal bridge is a weak point in the building envelope – edges exposed to the outside, reinforced concrete pillars, the joints where the balconies and roof connect, etc. These weaknesses will usually cause an overall decrease in the performance of the building envelope, leading to increased heat loss, mold and condensation. These are all problems that can be easily avoided with careful design, attention to detail and to thermal comfort.
Here is a photograph of the detail, with notes in Italian that read (left to right): 80mm insulation, no insulation, 40mm insulation.
To better understand the seriousness of the problem, let’s try to reconstruct the situation in a calculation software, to carry out the verification of the design temperatures (to control the final thermal comfort) according to UNI EN ISO 10211, and to mold risk UNI EN ISO 13788 .
The axonometric detail of construction, with Italian notes that read same as above:
… And in plan:
We are now able to scientifically quantify the effects of this thermal bridge.
1. high level of energy consumption and discomfort
First, this defect will result in a high level of heat loss, which will increase the building’s energy consumption (still thinking Class B?). That will lead to a situation of discomfort for those who will live in that house. In this house, Class B or not, people will be cold.
Here is the verification of the temperature according to UNI EN ISO 10211:
2. risk of mold
Secondly, this weakness of the building poses a serious risk of mold growth on the interior surfaces of the corner walls. This risk is greatly increased by the fact that the project does not include a controlled mechanical ventilation system, able to dissipate the moisture produced every day at home.
The result of the verification of the mold risk, according to the UNI EN ISO 13788, is this:
The question that naturally arises from this discussion is:
Will this building ever achieve ‘Emilia Romagna Class B’ level certification?
The answer is probably yes. It will probably be a Class B building in Emilia Romagna, with a lot of mold problems.
This situation, which is obviously absurd, is due to the fact that the regional certification (required by law) is not yet handled like a real quality certification of the building as a whole, but only as an overall energy balance. In this balance, the problems we have in this article are not dealt with in enough detail.
It is for this reason that there are voluntary certifications for buildings, such as CasaClima / Klimahouse or Casa Passive / Passivhaus / Passive House , which ARE able to ensure thermal comfort, the quality of the construction and the effective energy efficiency. A voluntary certification, in and of itself, will not make or break a well designed project. This is why, especially if you are building a home for yourself and your family, it is much more important to hire an architect who can follow the project carefully from beginning to end. If you want to buy an already built property, then these additional voluntary certifications can give you a real guarantee of what you are buying.