How many square feet was the original white house square feet?   I'm not sure how many square feet it was originally, but today it is estimated at 55,000 square feet. It has undergone several renovations and additions over the years, …so the original figure would have been considerably less. However, it was considered the largest private residence in the country until after the Civil War, so it was sizeable even when it was first built. The architect, James Hoban, modeled the home after the Duke of Leinster's House in Dublin, Ireland, but I can't say whether or not he followed the exact dimensions.