Insulation methods are many. Regular standard methods are least expensive and should be included in the bid price.Special needs insulation may be added relative to needs and preferences.Bathroom interiors walls are not normally insulated, but if you want additional sound privacy, additional insulation can be added to deaden same.Media rooms may have special consideration for obvious reasons.If any plumbing pipes had to go on any outside walls, they should definitely have extra protection from freezing.Insulation ventilation is a must.Never fill the entire bay without space for air circulation.Never squash insulation. It actually loses it's value if squashed.Soffit ventilation is important especially if vaulted ceilings are in the design.Ridge vents are the state of the art, along with soffit venting and styrofoam baffles for air flow.