Trump doesn't have the right to tear down the White House. It doesn't belong to him. It needs to go through a design approval process.
By law, any money spent by the executive needs to come from Congressional appropriation.
https://en.wikipedia.org/wiki/Antideficiency_Act
> The Antideficiency Act prohibits federal employees from ... accepting voluntary services for the United States, or employing personal services not authorized by law, except in cases of emergency involving the safety of human life or the protection of property. 31 U.S.C. § 1342.
Trump said the project "won't interfere with the current building. … It will be near it but not touching it. It pays total respect to the existing building, which I’m the biggest fan of. It’s my favorite place. I love it." Then, he sent in bulldozers to bring the whole thing to the ground.
Trump is also requesting the government, of which he is the head, to cut him a check for nearly a quarter of a billion dollars.
Trump has engaged in illegal impoundment and rescission of funds and programs appropriated and authorized by Congress.
Republicans in Congress and serving on the Supreme Court are failing to check Trump's lawlessness.
Trump has stated that he would like to serve an unconstitutional third term as president. If this comes to pass, it would mark the end of the American democratic experiment.