Luce lunare per gli edifici storici. Ricerca progettuale e sperimentazioni per la definizione di principi di illuminazione architetturale / Moonlight on historic buildings. Design research and experimentation to define architectural lighting strategies

The paper presents an innovative approach to lighting design, to be applied to histor ic architectural contexts, as an alternative to the general illumination trend that tends to distor t the cor rect reading of the building. Lighting design, as a par t of the whole architectural project, is responsible for the restoration of the urban “night identity” . To achieve such result, the strategy goes toward the reduction of lighting intensity in the urban environment, and the valor isation of constructions’ sculptural, mater ial and chromatic character istics. To define the lighting model, the study has followed two stages: the first, to investigate the light’s physical character istics; the second, to study and test lighting devices and identify the suitable ones for the valor isation of histor ic buildings. To this regard, Palazzo Tassoni Estense in Fer rara was selected as case study. To be more specific, the on- field test sessions were operated on its East façade, conceived as a sum of three over lapping layers: the first layer interests the outer skin; the second concerns indoor environments (perceived from outside through the openings); the third is made by protruded and cave- in spaces of the façade (porches, ter races, windows intradoses, singular features as decorated frames or extruded elements, etc.). For each layer , specific lighting strategies and typologies were elaborated. The proposition for layer 1 cr iticizes the exter ior lighting style made with concentrated spotlights, which arbitrar ily highlight cer tain sector and features of the façade leaving others in total darkness. As a counter -proposal, a uniform base light is suggested: a faint “moonlight- looking” effect to integrally illuminate the building elevation without emphasizing par ticular spots. However , the achieved effect tends to flatten the sculptural values of the façade; therefore it is combined with the lighting strategies introduced by layer 2 and 3. The final result is reached, after several test on the case study, thanks to the use of the LED technology, which allows for a better management of the light, electronically changing its main features (colour temperature, intensity, colour ). Finally, a lighting device prototype has been designed to turn the illumination program into practice.

L’articolo presenta un approccio innovativo alla progettazione dell’illuminazione notturna da applicare in contesti architettonici storici, per fornire un’alternativa alla prassi frequente che tende a falsare la cor retta lettura degli organismi edilizi. L’illuminazione, quale par te della progettazione dell’architettura stessa, ha il compito di restituire una “ identità notturna” ai luoghi della città.