After 3 weeks we returned to a home whose exterior walls have been fully raised. The crew has been busy sheathing the walls and hoisting engineered beams into place. The engineered roof rafters are also in place and roof sheathing partially completed. This is the start of our building envelope, the single most important element of a Zero Energy Ready Home. The building envelope contains critical thermal, moisture and air control layers that will determine the ultimate performance of the home.