Q:

Simple Present. They build a house next to mine. Why is it wrong?

Why is it wrong to say they build a house next to mine? 
The explanation i got was nobody is building a house every year or every month next to yours.
The correct answer was they are building a house next to mine.
SO, my question is why cant I use simple present to state it as a fact?
I can use simple present to state a fact, right?
Ex: I am 6 feet tall(fact).
Ex: I like apples(fact).
Ex: They build a house next to mine(not a fact anymore)?? Why is it wrong??

A:

It can work in some contexts. Such as:

I have these neighbors. I tell them they should stay as far away as
  possible. What do they do? They build a house next to mine.

Or:

Do you know what those idiots do every summer? They build a house next
  to mine. I burn it down as soon as it's finished, and the following year they just do it all over again.

The first example is just colloquial talk in the present tense, where it's substituting (the tense) for the past.
The second example is a very, very special situation.
Generally, however, the correct way to say it is

They're building a house next to mine. Just to spoil my view, I think.

