The current status and challenges of real estate science's contribution to SDG Goal 6, "Access to and sustainable management of safe water and sanitation," are discussed by organizing the targets of Goal 6 at the scale of use and space.

Goal 6 of the SDGs has been achieved in Japan, ensuring access to water and a good sanitation environment. According to the 2008 Housing and Land Statistical Survey, 2.8％ of rental apartments do not have bathrooms, while only 0.7％ of owner-occupied houses do. And the quality of plumbing equipment is improving year by year. Study by Suzuki and Arai（2021） shows that the impact of plumbing fixtures on the price of second-hand detached houses is small. Study by So and Shimizu（2019） shows that the ability to plumbing fixtures has a certain impact on rental housing rents. It has also been observed that rents rise when older rental housing is refurbished with plumbing fixtures. However, plumbing facilities have the effect of increasing the satisfaction of residents.

Repair work of plumbing equipment is important in aging apartments. The area where the condominium Owner’s Association must repair is the common area. However, when the condominium owner’s association repairs the plumbing equipment, it is desirable to repair the exclusively-owned area as well as the common areas. In this way, the real estate value of the condominium can be maintained.

Today's challenges for public toilets can be said to be spaces and facilities that can be used comfortably by everyone without disparity, and a sustainable operation and maintenance system. It is important to consider the realization measures according to the type of building to be installed, location and regional characteristics. I propose solutions for this and introduce advanced examples.

In this paper, we first introduce the background and current situation of improvements in water facilities for toilets at highway Service Areas （SA） and Parking Areas （PA）. Next, the reduction on the environmental load by the replacement of conventional toilets with low environmental load toilets such as waterless urinals and urine diversion toilets was quantified and cost-benefit analyses concerning introducing such low environmental load toilets were performed through simulations. Finally, we summarize our thoughts based on these findings.

The purpose of this paper is to provide an overview of the current state of ageing water supply infrastructure, to identify how municipalities are attempting to cope with aging water supply infrastructure, using the case study of Yokohama City, and to examine future issues for addressing ageing infrastructure. Issues such as what should be the basis for calculating water rates and how much asset maintenance costs should be included in water rates will be presented.

The Bureau of Waterworks has been managing the forest in the watershed of the Tama　River on the upstream of Hamura Intake Weir as the Water Conservation Forest for over 120 years. The bureau is working on communicating with various actors more actively through introduction and utilization of water resources area, disseminate information of the Water Conservation Forest to realize friendly water resources area. As part of the effort, the Tokyo waterworks bureau has introduced a naming right scheme “Tokyo Waterworks - Corporate Forest （Naming Rights）”, involving collaboration between the bureau and companies. This scheme allows companies to set naming rights areas in part of the Water Conservation Forest and provide opportunities to experience forest conservation activities. In addition, the bureau has also conducted the “Corporate Sponsorship Scheme” to promote forest management with enterprises.

To analyze the relationship between human investment items （including environmental performance of workplace）, human capital-related indicators, and corporate value （human capital）, this study conducted a survey of office workers via an Internet questionnaire. This study revealed the following two main points. 1. Environmental performance of workplace is strongly correlated with human capital-related indicators. 2. Environmental performance of workplace is strongly correlated with corporate value （human capital）.