The certification systems are designed to compare the impact of buildings on environmental resources, society, and the economy. The LEED lights certification is one of these— the voluntary certification of a building that follows the American system (Leadership in Energy and Environmental Design). This certification is used to build buildings capable of "functioning" in a sustainable and self-sufficient way in terms of energy; in short, it is a system for the development of environmentally friendly buildings. The organization that defines and promotes the LEED lights standard is a non-profit association founded in 1993.

LEED lights is a flexible and articulated system that provides different formulations for new buildings, existing buildings, schools, and small houses. The system is based on the attribution of credits for each of the requirements characterizing the sustainability of the building. In lighting design, it concerns energy savings, ultimately summarizing compliance with the value limits ​​of watts per square meter. Consequently, if the project or client requires it, it becomes a fundamental aspect of the design.

Following this brief tangent, which clarifies the purpose of the LEED certification, we can try to understand how a lighting designer works on a headquarter project. When designing a headquarter, the designer or lighting designer must consider that the complex will become a business card for the company, a place where its history and essence should emerge. Architectural lighting requires the elaboration of ideas involving cooperation between the external environment, with which architecture and interior architectural lighting relate and which should be designed to generate well-being and comfort.

Architectural Lighting │ Development of Lighting Design for Offices

The quality of workspaces is a complex design theme as it has to link the exterior and interior, from the architectural lighting of a façade to the interior lighting design. The façade usually responds, in fact, to the dual need to guarantee the solar shading of the internal environments and at the same time allow the maximum visual permeability of the surrounding environment.

Each of us has different needs. Consequently, in the architectural lighting of the workplace, there must be physical and psychological well-being, understood as the peaceful execution of one's own activities. This means supplying an adequate quantity of luminous flux and creating lighting conditions that enable these activities to take place in the best possible way with positive contributions to production. The appliances must be installed at the right height so as not to dazzle or be an obstacle, following regulatory parameters. The lighting designer must be able to use them in the architectural lighting of an office. Taking an ergonomic light as an example, a design solution could be to add table lamps, which can be moved depending on who needs more or less light, as each individual has a different perception.

Rules indicating the requisites to ensure good lighting in the workplace exist but it is always necessary to verify that the conditions are actually complied with and if the lighting systems have been created as works of art. Employees provide excellent feedback regarding their appreciation of the workplace lighting quality; in this case, participatory design can be a good tool for the design of interior lighting. Comfort, visual performance and safety are the main lighting requirements considered in the UNI EN 12464-1 "Light and lighting - Lighting of workplaces - Part 1: Indoor workstations". The lighting object in the standard can be daylight, artificial light or a combination of both.

Among the parameters considered to define the lighting environment is the distribution of light, the direction of the light illuminating the interior spaces, the variability of the light (levels and colors of light), and glare. To create a balanced distribution of light, the brightness of all surfaces and the reflections and contrasts that are determined must be taken into account, also preventing bright light sources from causing glare and, in this case, providing proper shielding. The UNI EN 12464-2 standard "Light and lighting - Lighting of workplaces - Part 2: Outdoor workplaces" is also important.

The standard specifies the lighting requirements for outdoor workplaces to meet the need for visual comfort and performance. During the interior lighting design of workplaces, in the arrangement of points of light, lamps with emergency functions must also be positioned, whether they are the same ones that also provide ordinary lighting or lamps for emergencies only, all to guarantee the illuminance values indicated by current legislation and, in particular, the UNI EN 1838 standard.

ENI Headquarter │ From the Design of Urban and Architectural Lighting to Interior Lighting Design

The project area is located inside a former industrial complex. The three communicating office towers of the ENI Headquarter, stretching horizontally are built around an empty space— the square. This is the symbolic heart of the project and public green surrounds the entire complex. The main objective of the lighting design of this large area was to highlight and make the various areas recognizable, as well as highlight the points of access and walkways; light as a design language and visual effect at the service of the various visual tasks. The research, aimed at creating a heterogeneous environment characterized by contrasts led to the identification of recently designed appliances using exclusively LED sources.

These featured high efficiency with a particular emission of beams controlled through a specific optical system, durability, reduced maintenance-replacement costs, clean light free from IR and UV components, flexible light point installation, the possibility of a strong spot effect (almost point source), safe operation with very low voltage, absence of mercury, duration not influenced by the number of times switched on and off, and the possibility 'to create smaller lighting fixtures. The study and attention to positioning and installation methods have allowed the creation of solutions built into the architectural elements, consistent with the compositional rhythm of the spaces and coordinated with the system requirements. 

In all projects, we try to hide the illuminated luminaires as much as possible. The lighting calculations confirmed the correlation between the architectural lighting project and the external parameters required for the environmental sustainability of the intervention. With their attention to the visual comfort of the users, the levels of illumination, and the color rendering of the sources, the adopted solutions follow the guiding principles set out in the respective regulations, as in the development of the SNAM Headquarter project.