Built capital is the stock of fully functioning infrastructure that does not degrade
other forms of capital including natural capital. Built capital includes buildings,
sewer treatment plants, manufacturing and processing plants, energy, transportation,
communications infrastructure, technology and other built assets. Investment
in physical capital is in construction, renovation, and maintenance. Physical capital
depreciates with use and requires ongoing investment to maintain its value. The
income or earnings generated by physical capital exist only in relation to its use. For
example, sewer and water treatment plants contribute to human capital (health).
Schools contribute to human capital (skill development) and social capital (if they
are used as community gathering places) and may contribute to natural capital (if
they include natural areas that are maintained or protected by the school).