Citation: Ferrante, T.; Villani, T. Pre-Occupancy Evaluation in Hospital Rooms for Efficient Use of Natural Light—Improved Proposals. Buildings 2022, 12, 2145. https:// doi.org/10.3390/buildings12122145 Academic Editors: Simone Secchi, Nicoletta Setola and Luca Marzi Received: 9 October 2022 Accepted: 30 November 2022 Published: 6 December 2022 Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affil- iations. Copyright: © 2022 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/). buildings Article Pre-Occupancy Evaluation in Hospital Rooms for Efficient Use of Natural Light—Improved Proposals Tiziana Ferrante and Teresa Villani * Department of Planning, Design, and Technology of Architecture, Sapienza University of Rome, 00196 Rome, Italy * Correspondence: teresa.villani@uniroma1.it Abstract: This paper aims to contribute to the formulation of criteria for the design of inpatient spaces through the efficient use of natural light as a factor that greatly influences human health. Specifically, it concerns the development of a methodology to assess the quality of natural light in the operating phase and demonstrate how the morphological and material characteristics of the hospital rooms can affect natural lighting. All variables affecting light in indoor spaces have been evaluated, with a focus on the photometric characteristics of finishing materials and furnishings, aimed at determining their contribution in terms of reflectance. This evaluation was based on pre-occupancy evaluation methodologies, which allow comparing actual and simulated natural light conditions, and was tested on a sample of inpatient rooms located in a hospital in Rome. Improvement design solutions were proposed and simulated through the evaluation of physical variables including daylight factor, illuminance, color rendering index, etc., selecting the ones with appreciable improvements over ante operam natural light conditions. The methodology allows control over the effects of individual interventions, specific to each variable, highlighting their impact on visual comfort and their feasibility from an economic and operational point of view. Keywords: visual comfort; inpatient room; hospital design; pre-occupancy evaluation; building performance evaluation 1. Introduction Hospital buildings are complex facilities with different needs regarding health, preven- tion, and care. Therefore, the starting point for any kind of design choice should always be the extreme fragility of patients. Hospitals also represent important nodes in the territorial services network and should be designed as such: safe and welcoming places, both in terms of the quality of the services provided and for the functionality of their spaces [1]. Many environmental factors contribute to the achievement of the desired quality and affect the health of patients [2,3]: indoor air quality, good natural ventilation, and the quality of natural light, as well as aspects related to the quality of healthcare services and the concept of patient-centered care [4]. In particular, light makes it possible to perceive the quality of living and care environments, affects human behaviors and has a direct and indirect influence on mood and cognitive processes [5]. Indeed, natural light, as a factor identified among those that would require more study and research [6], is the specific focus of this work. Important studies have shown through evidence how the extra-visual effects of light on the human body plays a decisive role on physiology, on psychology, and on the ability to generate conditions of well-being in humans [7], and have linked natural lighting with the circadian rhythm [8,9], responsible for the regulation of many daily activities (e.g., energy metabolism, feeding times, and endocrine and immune functions with related pathological conditions) [10]. Exposure to natural light during the day inhibits the production of mela- tonin, allowing the regulation of the wake–sleep rhythm [11,12], especially for bedridden or elderly people [13]. Buildings 2022, 12, 2145. https://doi.org/10.3390/buildings12122145 https://www.mdpi.com/journal/buildings