Environmental features include a free home energy rating report with their property valuation, which covers the energy efficiency of the property, and points out ways in which it can be improved.
In addition the Bank will also make an annual donation to Climate Care to help tackle global warming for the duration of the mortgage.
Mick Firth, deputy chief executive of The Co-operative Bank, said: "With our new fixed rate mortgage, borrowers have the peace of mind that however much interest rates may rise over the next three years, the amount they are paying will not change.
"The Bank returned to the mortgage market in 2000 when we launched our flexible mortgage and last year we introduced our capped rate flexible mortgage. Our new fixed rate mortgage now provides a further option, which we believe will be attractive to many borrowers."
Other features include a maximum advance of 95 per cent of the property value, daily interest charges and flexibility. Borrowers can create a ‘flexible fund’ to either pay off up to 10 per cent of the mortgage balance each year without penalty, withdraw all or some of the fund at anytime, or use it to take a repayment holiday.