After this trade, Houston is already at about $150,000,000 in cap used next season before needing money to sign draft choices. It will therefore likely have to dump some players to gain cap room and/or trade away some of next draft season's choices. Not an enviable position to be in. We've seen this before. (Remember Dallas?)
With the 5% increase in cap room next season all teams will have $153,153,787 to work with. Houston has used $115,978,656 next season, leaving $37,205,131 for Houston to work with. Houston's draft picks will likely cost roughly 7 million, as they have no first rounder and will likely cut 5-7. I used Beta 87 as a reference for the cap cost, and used last years draft slots for Houston which was the eighth pick. Plus Washington's 3rd. The exact number I came up with for Houston's draft picks next season, which obviously isn't perfect is $6,921,369. After draft picks next season Houston would still have roughly 30 million to work with. I see no cause for concern at this point in time. I think you saw $115 million and thought it said $150 million.