The delay is not expected to affect the construction and design capital budgets for the multi-million dollar project, which was supposed to be finished in June 2013 in time for the football season that year.
FOL had opposed Lansdowne's changes, alleging the city broke its own procurement rules by sole-sourcing a $300 million contract to the Ottawa Sports and Entertainment Group. That case was overturned in the Ontario Superior Court earlier this month.
OSEG is also said to be partly blamed for the situation due to its decision to change architects during the development process.
Separately, Lansdowne also faced a challenge from community groups, but a settlement reached with them met Ontario Municipal Board approval in June.
Under the new timeline, the revamped stadium should be completed by 2014, and the entire complex – including retail, a mixed-use area and a park – finished by 2015.
The city is proposing completing more of the stadium design work ahead of construction to minimize the delay.
A memo detailing the timeline changes will go before the city's finance and economic development committee next Thursday.