"I can't do that, especially not in the house" vs "I can't do that, especially in the house."

Question

I can't do that, especially not in the house.

I can't do that, especially in the house.

Are both of these sentences grammatical/acceptable? What is the difference in meaning between them?

Answer 1

They actually have the same meaning. In your first sentence

I can't do that, especially not in the house.

Especially is used to emphasize the prohibition.

Answer 2

I can't do that, especially not in the house.

means when not in the house, it's even harder for me to do that.

---

I can't do that, especially in the house.

means when in the house, it's even harder for me to do that.