The Lansdowne 2.0 redevelopment plan could provide much more money for affordable housing, and a third tower and the arena's green roof could be resurrected if motions to amend the $419-million plan are approved this week.

Members of the finance and planning committees are in the midst of a marathon meeting on the latest revitalization plan, which will last at least two days.

Councillors introduced two competing motions for increasing the level of funding for affordable housing. As the plan stands, only 10 per cent of the value of air rights sold to developers to create residential towers would go to an affordable housing reserve. No affordable housing will be built on site.

One motion would hike that to 40 per cent, bringing the contribution from an estimated $3.9 million to nearly $16 million. Another would set the contribution at 25 per cent, aligning the plan with existing rules for selling off city land.

When councillors got a look at the revised Lansdowne redevelopment plans last month, they discovered that one of three residential towers was dropped. The loss of new property taxes is a key reason that staff say the project is no longer "revenue neutral."

Coun. Tim Tierney introduced a motion to bring back a third residential tower that was dropped from the initial Lansdowne 2.0 redevelopment plan.

"Obviously, we have a housing crisis," said Tierney. "We've got to start flooding the market.… We need more units."

Coun. Theresa Kavanagh introduced a motion to reverse another change to OSEG's original design and include a green roof on the new arena.

There are 86 public delegations signed up to weigh in on the plans, but councillors told CBC they've already received a deluge of emails and calls.

Representatives from the city and its private partner, the Ottawa Sports and Entertainment Group, presented the plan to the joint committee on Thursday morning, urging councillors to make a decision on the file that will address issues that have so far made the project financially unsustainable.