The influence of Daylight in the Housing Market - A case study in Turin

Daylight is essential in the architectural field, since the preliminary design stages onward, and along all the life cycle of a building. It influences the psychological and physiological aspects in human beings, as well as the energy efficiency of a building, as it can contribute to decreasing the energy demand for electric lighting and cooling. As a consequence, daylight is often mentioned above the most important factors by people when it comes to buying or leasing an apartment, which means that daylight can play a role in the determination of prices in the real estate market. Within this frame, the aim of this thesis is to investigate and to try to quantify the impact of daylight in the real estate. A data sample of 100 housing units was built, selecting units in the district called Pozzo Strada, in Turin. The sample includes both classic variables as taken from the market advertisements, such as the surface of the unit, the construction year of the building, the location, and the view, as well as some green variables related to daylight, such as the type of glazing (single or double) and frame (wood, PVC, or aluminium) used in the window. Particular attention was paid to the daylighting amount inside the units, calculated through simulations in terms of average Daylight Factor, or through other climate-based daylight metrics (spatial Daylight Autonomy, Useful Daylight Illuminance, and Annual Sunlight Exposure). These climate-based daylight metrics have been found through simulations using the validated software ClimateStudio and inserted in the database. Once complete, a Multiple Regression Analysis is carried out, starting from the Spearman Correlation Analysis and followed by the removal of the outliers, if present. After multiple models with the listing price per square meter as dependent variable, a final Multiple Regression Model to explain the significant factors on the final price of an apartment was defined. The final results demonstrated the relevance of daylight in the real estate, and at the same time identified which of the new green variables included are actually significant. Among them, the Annual Sunlight Exposure resulted significant and with a positive marginal price, together with the façade typology. Although significant, the frame typology resulted in a negative marginal price. To a minor extent, the Useful Daylight Illuminance was also found to be significant, while the average Daylight Factor didn’t result significant.