Bruce Robertson of Robertson Holden International Speedway said the design was a fantastic concept.
"The new concreted pits will be more serviceable for the cars which currently sit on grass."
The pits are to be relocated in 2019-2010 to provide space for the new entrance plaza and concourse on Cuba St that links the city and Arena.
A green space on Cuba St will be maintained and an 8m-wide landscaped pedestrian concourse has a designed flare zone beneath for fire safety vehicles.
The pedestrian concourse will allow easy flow and when the speedway is operating, pedestrians can look down into the pits.
PNCC manager property Bryce Hosking said a business case for the commercial building is in the early design stage.
"We are looking at a feasibility study. It needs to be able to stand on its own.
"Tenants will have to maximise the space and value to the Arena."
Sport Manawatū is still part of the steering group.