Preheat the oven to 350°F (175°C). Line two baking sheets with parchment paper.
In a medium bowl, whisk together the all-purpose flour, baking soda, and salt. Set aside.
In a large bowl, beat the softened unsalted butter, granulated sugar, and light brown sugar together until creamy and smooth, about 2-3 minutes.
Add the eggs one at a time, beating well after each addition, then mix in the vanilla extract.
Gradually add the dry flour mixture to the wet ingredients, mixing until just combined.
Fold in the semisweet chocolate chips evenly.
Roll out the cookie dough on a lightly floured surface to about 1/4 inch thickness.
Using a printed template or cookie cutters shaped for house walls and roof panels, cut out the pieces needed for the house structure.
Place the cookie pieces on the prepared baking sheets and bake for 12-15 minutes or until the edges are golden brown.
Remove from oven and let cool completely on wire racks to harden.
While the cookies cool, prepare the royal icing by beating the egg whites and cream of tartar in a large bowl until foamy.
Gradually add the sifted powdered sugar while continuing to beat until stiff peaks form and the icing is thick enough to hold its shape.
Transfer the royal icing to a piping bag or resealable plastic bag with a small corner cut off.
Assemble the cookie house by piping royal icing along the edges of the cookie pieces and pressing them together gently. Hold each joint for a few seconds to set.
Allow the assembled house to dry and set for at least 1 hour before decorating or handling.
Decorate the cookie house with additional royal icing designs or candies as desired.