An insulated enclosure includes a plurality of walls, each of the walls comprising structural insulated panels joined to adjoining structural insulated panels by joints. Each of the structural insulated panels includes a frame having a first vertical frame member, a second vertical frame member, a top frame member, a bottom frame member, and siding members disposed on opposing sides of the frame to define a cavity therebetween. The vertical frame members define, on an outwardly disposed surface thereof, a plurality of vertical recesses and projections. The joints between the plurality of structural insulated panels are butyl-free and include butyl-free compressible seals disposed between opposing recesses and projections in adjoining structural insulated panels. Insulation is disposed within the structural insulated panels and within at least a portion of at least one structural insulated panel vertical frame member.