Heat insulated wall structure includes interior blanket insulation positioned between adjacent ones of studs, interior of the exterior wall board. Reflective sheet material is placed adjacent the blanket insulation, and the interior wall board is applied over the reflective sheet material to the studs. Spacers are applied to the heat reflective sheet material so as to maintain the facing surfaces of the reflective sheet material and the next adjacent surface in spaced relationship, forming a dead air space therebetween. The dead air space adjacent the heat reflective sheet material maintains the high reflectivity properties of the reflective sheet material, giving the enhanced ability to reflect heat away from the interior of the wall structure.