It's a deal which promises to transform Ottawa's downtown core and secure the future of the Ottawa Senators in the capital.

The National Capital Commission and RendezVous LeBreton have agreed in principle for a fair market value of 53 acres of land right in the heart of downtown Ottawa.

The RendezVous proposal is a $4 billion dollar development deal which includes a new downtown NHL arena.

Ottawa Senantors owner Eugene Melnyk was at the NCC board meeting today. 

"My goal has always been to provide the Senators with home ice advantage," Melnyk said in a tweeted statement. "Though there are still many hurdles to overcome I’m thrilled to be one step closer to a more enjoyable fan experience and realizing a vision for LeBreton Flats."

The CEO of the National Capital Commission Mark Kristmanson said the two sides will negotiate for the next 18 months with the goals of getting the shovels in the ground by 2019/2020.

"It's going to take a sustained momentum on everyone's part but I can't believe that there are not investors who will want to be part of this and they now have a firm basis to go seek that financial support" Kristmanson said when asked how long the group has to secure the necessary funding. 

Kristmanson would not provide details about how much this project will cost taxpayers, but did say federal taxpayers will benefit overall. He also said the land will be purchased "at fair market value" with consideration for how much it will cost the group to decontaminate the site. 

Ottawa Mayor Jim Watson said he is thrilled to see development of the piece of prime downtown real estate. 

"To have the arena and shops offices, all together is going to be something we are all proud of over the next 15 to 20 years," Watson said. 

The federal government still has to sign off on the project, as does the city of Ottawa. 

Phase 1 of the project will include everything in the public realm, including the new NHL arena, abilities centre and a major events site. When those projects will be completed and what the timeline looks like is still to be determined.