5. The Urban and Environmental Building Code as Implementation Tool

The National Action Plan, Directive 2009/28/CE of the European Parliament and of the Council, April 23rd 2009, based on the incentivation of the use of renewable sources for the energy needs, is a programming document. The latter gives detailed indications about the actions to be set out in order to reach by 2020, the constraining objective for Italy to cover the 17 % of the gross national consumptions through renewable energy. The objective can be reached using renewables sources in the following areas: Electricity, Heating–Cooling and transportations (in http://​approfondimenti.​gse.​it).

The Joint Research Centre is within the Covenant of Mayors the european institute for the validation of the SEAP that are elaborated and presented by the municipalities.

The Directive, inter alia, raises the need to “increase the rate of restructuring of real estate, as the existing building stock represents the individual sector with the greatest potential for energy savings” stating also an annual rate of 3 % of mandatory restructuring for buildings owned by their central government in order to improve their energy performance.

As stated by the new Directive, to learn about the energy performance of buildings no longer the technicians have to refer to ‘energy efficiency’, but their ‘energy performance’ (annual amount of primary energy actually consumed or expected to be required to meet with a standard use of the property, the different energy needs of the building, winter heating and summer, the preparation of hot water for sanitary use, ventilation, and for the tertiary sector, lighting. Such a quantity is expressed by one or more descriptors that also take into account the level of insulation of the building and the technical characteristics and technical systems.

Referring to the technical norms UNI TS 11300 parts 1, 2, 3, 4, reccomendation CTI 14/2013 and technical norm UNI EN 15193.

The Life Cycle Assessment is a methodology that evaluates a set of interactions that a product or service has with the environment, considering its entire life cycle that includes the stages of pre-production (and thus also the extraction and production of materials), manufacturing, distribution, use (and therefore reuse and maintenance), recycling and final disposal. The procedure LCA is internationally standardized by ISO 14040 and 14044 norms (http://​it.​wikipedia.​org).

The Italian norm CEI 205-18, transposing the european norm EN 15232, is a practical guide to the use of Building Automation technologies in buildings, clearing out how starting from a building without automation measures for thermal and electrical plants (class D building according to the EN 15232), it is possible to attain large energy savings by means of the installation of automation functions. As an example the CEI norm states that it is possible to get a reduction of thermal energy consumption of 26 % by installing class A automation systems.

In the case of new buildings or buildings undergoing major renovation, facilities for thermal energy production must be designed so as to ensure the respect of the contemporary coverage, through the use of energy produced by plants fueled by renewable sources, of 50 % consumption required for domestic hot water and defined percentage of the sum of the estimated consumption for domestic hot water, heating and cooling, variables with respect to the date of presentation of the building to the municipality. These obligations can not be fulfilled by renewable energy plants that produce only electricity which, in turn, devices or equipment for the production of domestic hot water, space heating and cooling.

Article 2, comma 1-m of the decree 28/2011: “building strongly restructured” is a buildings falling into the following categories:

(i) existing building with a floor area greater than 1,000 squared metres, subjected to integral restructuring of the building elements of the envelope; (ii) existing building subjeced to demolition and rebuilding also in extraordinary maintenance.

The energy classification of buildings in Italy, till now, was executed referring to the quantity of primary energy per m², required for heating and sanitary hot water production. The energy scale for buildings ranging from A+ to G represents the index of global primary energy (EPgl) given by the summation of the indices of energy performance for winter heating (EPi)—representing the energy consumed in one year to heat one m²—and for hot water production (EPacs). The latter value depends, largely, for the production means, namely if it is employed a centralized source or a local autonomous source, with gas supplied boiler or electrical boiler. It must then be considered that, the average energy consumption of the buildings realized before 1977 in Italy it is 200 ÷ 250 kWh/m² per year (Class G). Such consumption must be compared with the average energy consumption in Germany, Austria, Switzerland and Denmark of 20 ÷ 50 kWh/mq per year (in http://​energaiacn.​it/​home/​61-certificazione-energetica-e-valore-edifici.​html).

National law, whose first version was issued in 2009 (Berlusconi government) in order to support the building sector offering the citizens the possibility to restore or enlarge the volume of buildings with a strong simplification of burocracy, overcoming the local municipal urban plans and introducing energy efficiency measures as a couterpart. Each italian region has then issued a regional law, concerning the matter. In Sicily the possibility to benefit from such law is extended till August 2014.

Grid parity occurs when an alternative energy source can generate electricity at a levelized cost that is less than or equal to the price of purchasing power from the electricity grid. The term is most commonly used when discussing renewable energy sources, notably solar power and wind power. Reaching grid parity is considered to be the point at which an energy source becomes a contender for widespread development without subsidies or government support. It is widely believed that a wholesale shift in generation to these forms of energy will take place when they reach grid parity (http://​it.​wikipedia.​org/​wiki/​Grid_​parity).

National Observatory of Building Regulations.

Concerning the implementation of social services supporting a urban site, such as schools, churches, or green areas.

Research and dissemination project within the SAVE Intelligent Energies program, developed between 2005 and 2007, aiming at the promotion of passive houses in hot climates proposing to analyze the way to extend the passivhaus design concept to Southern Europe.

Measured with the airtightness test (Blower Door Test) allowing to define the equivalent air flow for infiltrations at a pressure difference of 50 Pa (V₅₀).The number of air turnovers per hour at the pressure of 50 Pa is indicated with the index n₅₀. Such values allow to evaluate the quality of the building coating under the airtightness profile. The lower the value the more efficient the coating. Indeed a cold air infiltration from outside or the leakage of hit air from the inside, due to not perfect sealing, become a concentrated flow of water and steam. As a result the condensation inside different components such as walls, node wall-subframe, node subframe shutters, thermal insulation, roofs, etc.). The effects are quite negative: the thermal conductance of a material increases with the internal increased humidity and the retention of condensed water in the structures damages the materials, favours the upcome of mold, causes a decay of the living comfort. Moreover molding phenomena in wooden structures can take place or the fast deterioration of insulating materials (Ronchini 2012).

The degree of selectivity is described by the ratio between visible transmittance and solar factor.

The interventions are described in article 3, paragraph 2, letters (a), (b) and (c) number (1) of the Italian Legislative Decree n. 192/05 and modifications: (a) number (1) integral restructuring of the building elements constituting the coating of existing buildings with floor area larger than 1,000 m²; (a) number (2) demolition and reconstruction in extraordinary maintenance of existing buildings with floor area larger than 1,000 m²; (b) volume increase (gross heated) larger than 20 % of the entire existing building (the application is only related to volume increase); (c), number (1), interventions on existing buildongs such as total or partial restructurings and extraordinary maintenance of the building coating and volumetric increase out of what already considered in letters (a) and (b) (only for the part of coating or of volume object of the intervention) [Update of the Italian Legislative Decree n. 311/06].

One of the key aspect of making low-energy buildings is the care given to the thermal insulation. That means using the right materials with the right thickness to provide the right thermal coating. But this is not enough. The thermal insulation must not have holes where heat would flow thus defeating the purpose of the thermal insulation. Fighting those thermal bridges is essential in making excellent quality low-energy consumption buildings. Thermal bridges are localized regions in a building which display increased thermal losses. They can be caused by components whose geometry, such as balconies, or whose materials, such as aluminium window frames without thermal break, have higher thermal conductivity. Thermal bridges are most often created by the structure of the building, at the junction of walls and floors, at the junction of walls and roof, in the corners or around windows if they are not properly installed. Interior thermal insulation is well known to create many thermal bridges that could be completely avoided for example by doing exterior thermal insulation (http://​beodom.​com/​en/​education/​entries/​fighting-thermal-bridges-or-how-to-make-better-buildings).

The thermal capacity is the property that certain materials have to absorb and retain heat in time, and this is measured in relation to the number of hours of temporal delay between the input of the heat flux incident on the exposed face (external) and its release on the opposite side (inside). To be effective, the material mass must be able to ensure a delay in the passage of the thermal wave such that the heat is released inside during the coolest hours of the day. The delay of the thermal wave, due to the heat capacity, is called displacement, while the reduction of the temperature on the inner surface, with respect to the external surface temperature, is called attenuation factor.