**4. Discussion**

Heritage public bathhouses (hammams) of North African Maghreb cities continue to provide an affordable hygiene and well-being facility for their residents. This is particularly the case in Morocco which has the largest number of heritage hammams. It is estimated that there are at least 12,000 hammams operating in Morocco. However, this number is likely to be much higher as new hammams are being built in every single new residential neighbourhood and no recent statistics are available to date. As hammams operate day and night, their electricity bill for lighting the building constitutes 25% of their energy consumption, the remaining 75% are for water and building heating [17]. The reintroduction of daylight into the bathing spaces is therefore estimated to reduce energy consumption by at least 12.5% (half the time is at night) and create healthier environments for both bathers and hammam workers.

The repair of the vernacular lighting system in heritage hammams of all historic urban centres in Morocco and in other North African cities can have a cumulative effect on reducing CO2 emissions and increase users' well-being as well as revive the glass blowing crafts using recycled glass for the production of oculi glass caps. Furthermore, its adoption and adaptation to contemporary hammam projects can achieve higher levels of horizontal illuminance by increasing the number of roof oculi in the design of new structures in order to meet contemporary expectations of visual comfort from the users while maintaining architectural and cultural authenticity. Bathers, however, lack experience of the original luminous environment and their expectation of higher levels of illuminance has been reported through discussions with the manager of hammam Rjafalla. Although, bathers and staff were happy to see more daylight in the bathing spaces after the rehabilitation of the vernacular system, and commented positively about it, they still expected additional electric lighting to be used, particularly at the end of the summer months. The cultural and religious norms relating to nudity and visual privacy still apply to some extent in the use of the bathing spaces, although they are not always adhered to.

Despite the limitations of previous studies on hammam daylighting in other geographies, it is clear from the results of this study that the horizontal levels recorded in the present case study fall far below those measured in Ottoman hammams where the number of oculi in the roof is much higher than those found in Moroccan hammams.

Moroccan hammams fall under the umbrella of the Ministry of Habous and Religious Affairs (who own the majority of the heritage structures) and the Ministry of Culture and Traditional Crafts. Serious attempts have been made to reduce wood consumption in hammam furnaces to reduce CO2 emissions, particularly after the COP 22 event held in Marrakech in 2016. However, the reduction of electricity consumption through the reintroduction of daylighting has not been considered. It has also been omitted by a study conducted by the Ministry of Culture and Moroccan Crafts aimed at establishing benchmarks of what constitutes an authentic Moroccan hammam [18]. Furthermore, the integration of bespoke off-grid LED solar powered lighting within the vernacular daylighting system for night illumination, as developed by the author in 2015, can lead to a highly sustainable hybrid innovative solution [17].
