I did a 3D model of a stadium design, loosely based on the InfoCision stadium in Akron, Ohio (
http://shopping.ohio.com/SS/Page.aspx?secid=69534&sstarg=&pagenum=5 ). That stadium cost $61 million to build. However, it has a large media tower and a higher second tier of seats. Also, it doesn't have the corner sections of seats as in the 3D model.
The 3D model field dimensions are 235 feet wide (20 feet extra on each side line) and 480 feet long (15 feet extra in each end zone). Based on other stadium designs for Canadian Football, this would be a fairly compact design. With
all seats, it would have a seating capacity of 29,000 (40 rows high). With
all bench style seating, it would be about 31,000. It could be expanded to 40,000 by completing both tiers of seats in the end zones. This is based on seats being 20" wide and bench style being 18" wide and having a 4 foot aisle way every 24 seats (for calculations, but in the model the sections are wider than this). Temporary stands could easily be set up in the end zones.
At 40 rows high, it is still quite low in height (about 40 feet from street level to the top of the seating rows). It is sunken by about 15 feet and the entrance gates would be raised by about 10 feet from street level. The row widths are 30 inches (this seems like a typical row width for stadiums, and it would not be cramped). The bottom tier of seating has a rise of 16 inches per row and the upper section is 18 inches per row. This should provide good vision of the field and is based on other stadiums and the book "Stadia, Fourth Edition: A Design and Development Guide"
The seats are arranged to allow for two roof sections that would completely cover the seating sections. The field and end zones would remain open. For the Halifax climate, it seems that an important criteria will be protection from the rain (or sun during the summer). It seems that most new stadium are currently being designed with some protection from the elements. For concerts, there would be additional room in the end zones and the field for concert goers. I would expect it to have a capacity of about 40,000-45,000 for concerts (without having to expand the stadium).
The end zones could be landscaped with flowers, bushes and trees. I uploaded the actual 3D model to Google 3D Sketchup. If anyone would like to download it then search for Halifax Stadium in the Google Sketchup 3D Warehouse. I attached a 2D image above. I think that the actual 3D model looks better than the 2D image above.