Building with ultra stable cementitious material formulation

A building comprising walls comprising a cementitious material, wherein the cementitious material is the product of blending:

• (i) 29 wt % to 40 wt % of a magnesium oxide dry powder, based on the final total weight of the cementitious material, containing 80 wt % to 98 wt % of magnesium oxide, the magnesium oxide having a surface area ranging from 5 meters2/gram to 50 meters2/gram and an average particle size of from about 0.3 to about 90 microns, and wherein more than about 90% by weight of the magnesium oxide particles have a particle size of less than or equal to about 40 microns;
• (ii) 14 wt % to 18 wt %, based on the final total weight of the cementitious material, of a magnesium chloride dissolved in water;
• (iii) 0.1 wt % to 10 wt %, based on the final total weight of the cementitious material, of a stabilizing material, the stabilizing material comprising:
• 1. an aqueous solution comprising 55 wt % to 65 wt % of phosphorous acid (H3PO3);
• or
• 2. an aqueous solution comprising 80 wt % to 90 wt % of phosphoric acid (H3PO4);
• wherein the cementitious material comprises an amorphous phase and a plurality of crystals, each of the plurality of crystals having a molecular weight within the range of 280 to 709, and being encapsulated by the amorphous phase of the cementitious material,
• wherein a majority of stabilizing material is consumed during curing into a nano-molecular veneer over the plurality of crystals while increasing surface area of the plurality of crystals by 2% to 49%, and
• wherein the nano-molecular veneer is insoluble in water and protects the plurality of crystals from degradation in water at temperatures from 20 degrees to 60 degrees Celsius for from 24 hours to 56 days.