The outcome of pending reports on the matter should be awaited instead, he told the National Assembly during question time on Wednesday.
Zuma was asked by Democratic Alliance parliamentary leader Lindiwe Mazibuko whether he was informed of the upgrades at his private home in Nkandla in November 2010. He replied, among other things: "Naturally, I was informed that improvements needed to be made at the family residence to enhance the security of the head of state.
"The nature and form of the improvements was decided upon by the relevant officials through their departments.
"As already indicated, such information would not include details on the specifics of what would be done, by whom and at what cost," he said.
'Tap dancing'
In a follow-up question, Mazibuko said Zuma was "tap-dancing around the issue", and must have known the cost and extent of the upgrade.
"I have a letter that shows he must have known. A letter addressed to him by former public works minister Gwen Mahlangu-Nkabinde, setting out the details of the project, including that money was being spent on non-security items.
"How is it that the president didn't know about or act upon a letter addressed to him by one of his own cabinet ministers?" she asked.
Zuma replied: "Firstly, I never received any letter. No letter has ever been received by me. Very clear, straight answer."
Secondly, the report of the public works department's task team appointed to probe the spending was before Parliament and still had to be discussed by MPs.
Details
"And I'm sure those details will come there. Wherein you look at these items and deal with them, whether they were security-related or not. I don't think I should pre-empt your discussion by discussing the report that is before Parliament. If there was no report before Parliament, it would be a different matter.
"I am also informed that the public protector is also either conducting an investigation, or about to conduct it.
"So, I don't think, besides saying I never received the letter, I should discuss the details," he said.
Pressed by more follow-up questions by the opposition, Zuma repeated that "no house of the president was ever built by government. I've said so at the beginning, I've repeated it".
"And I've said, secondly, the report is coming, which will clarify all of this. And I'm saying you'll discover no house was built by taxpayers' money of the president.
"Security departments said they needed to put security features in my houses that I built. Security features and houses are not one and the same … wait for the report. That will help you a great deal, so that you can ask more intelligent questions." – Sapa