For now, let's focus on supporting the floor joists using a floor joist beam. There are two main options for doing this:

1. Using a properly sized structural concrete or concrete block wall as support.

2. Utilizing a wood framed wall with suitable bracing.

The first option involves building an additional solid core wall that runs perpendicular to the direction of the floor joists and is designed to resist both vertical and horizontal loads. This type of construction provides excellent strength, fire resistance, and soundproofing qualities but can be more expensive due to material costs associated mainly because there aren't any cheaper alternatives available when trying away from standard lumber framing techniques without sacrificing structural integrity!

If budget constraints are a concern then we could always opt for Option 2 instead - which involves building two separate stud walls separated by an air space (usually filled with insulation). These studs will be placed close together so they can work together like individual beams providing additional strength across the width of our structure at low cost compared against installing full-size solid wall sections throughout entire span lengthwise before covering overtopalike manner later down line once finished out interior spaces feel comfortable enough living inside walls without feeling too boxed-in...

Lvl rafter span calculations