I want to calculate the life cycle cost of a Aliminuim chair given the following information:

Functional Unit: Providing an Aliminuim chairfor $1$ year

An Aliminuim chair lasts on average $20$ years and costs $450$ $ The production requires $35$ kg of Aliminuim and $14$ MJ of Energy. The Aliminuim price is at $2\mathrm{.}5$$$/$kg and the electricity price at $0\mathrm{.}5$$$/$MJ$.$ The disposal of the chair is payed for by the user and costs $10$$$/$unit$.$

Discounting

Addition information: The life cycle of the aliminuim chair extends over some years. The aliminuim is produced in the current year $($year $0),$ the chair is produced in year $3$ and the disposal occurs in year $20.$

The discounting rate is $3\%$

Discount the relevant monetary streams from the year they occur to the current year $($year $0)$