No, I didn't skip several letters in my lettering sequence. This type of house really is called an I-House. When these houses are built, they start with just the main facade part of the building, but as the family occupying the house grows larger, more rooms are added onto the back to make extra space available.

These houses are VERY common where I live (but I don't live in one).

Besides being found in rural areas, these houses are also commonly found in rows along the streets of cities and towns in the United States.