From recollection, I believe they’ve a small stipend for improvements, but anymore, most come from donations. From solar panels to vegetable gardens … to lavish rose gardens attempting to rival European 'royalty,’ it never ends.. I’m sure ‘her roses’ could easily be sold to their sycophants after the election, if added to trump shrines across the nation

There is a fund that the POTUS has access to.
No one knows when it was established, how much is in it, or how much is deposited each year.
The POTUS can use it for whatever he/she wants. And the Secret Service bodyguards are allowed to dip into it.
The funds are disbursed by the head of the White House Military Office. A former director of which wrote a book back in the 1980s about his experiences, from LBJs presidency through Jimmy Carter's.
According to him, JFK used it to build a fallout shelter under his Hyannisport MA home. LBJ used it to make some improvements on his Texas ranch. Nixon used it to build helicopter landing pads at his Key Biscayne, and San Clemente homes. Also to put in anti-shark screens around the swimming area at Key Biscayne. LBJ had a brother named Sam. And whenever he came to DC, he insisted on being picked up by chauffeured limos, and staying in the best hotels in Washington. So, that too, was paid out of the special Exexutive Fund.
Jimmy Carter used it to re-model his mom's house, under the pretext of it being a 'national historic site'." Take it while ya canJimmy", his mom allegedly told him. To which, he replied " I will momma! I will!"
I'm sure Trumpy was enthralled upon learning it was an added fringe benefit of being the POTUS. But what he dips into it for will have to wait until his chief of the WHMO writes a tell-all book.

There was a enormous flapdoodle when Nancy Reagan decided to spend mega-bucks on new china for the House. But she got it. Along those lines....has there been a single social event at the White House in the last four years? Remember when the Obamas had events to honor various artists? Visiting heads of State? Guess nobody's ever invited for "hamberders and diet cokes".....

Hey, think. When they satify their whims they keep a few people employed.

It's the later. No regard except for their greed that is never satisfied.