I think I figured it out... Look at this image
The club is at level 49 but there are 5 floors above... The club looks like it occupies 49-52.
Not sure what those top 3 floors will be for though.
Also just found this:
http://jeffpoh.com/m/altus-at-solo-district
Altus (second tower released) features:
9 foot ceilings
Units start on the 15th level with commercial below with this level being equivalent to 20th level due to height of each commercial floor
Club 55 is the premium, Hottest Rooftop Patio: top floor of building with 5000 square feet of amenity space featuring full kitchen, indoor and outdoor entertaining space
Fitness gym and garden areas
3 eleveators and concierge
Soft close doors and drawers in kitchen with quartz backsplash, stainless steel appliances
and many more features to list
The Club 55 Rooftop Deck at the top of Altus.
Pricing are as follows as of today and will increase when released to Public:
1 bedroom unit 539 sq.ft. starts at $294,900
1 bed and den 539 - 589 sq.ft. start at $304,900
1 bed and sleep/flex which can fit an additional bed at 665 sq.ft. start at $342,900,
2 bedroom 814 - 916 sq.ft. start at $415,900
2 bedroom and den 886 - 940 sq.ft. start at $467,900
2 bedroom and den 834 - 854 sq.ft. on 38th to 46th floor start at $497,900
3 bedroom 1032 sq.ft. start at $544,900
Penthouse 3 bedroom 1390 - 1707 sq.ft. start at $969,900