Such tax might be beneficial even now in some places. In Japan and Italy so many properties were bought out by people intending to profit from the rent that price of accomodation rose to the point that most young people can't afford to live alone and stay with parents instead.
UBI funds have to come from somewhere. Depending on the source of the money, UBI will either create low inflation or large inflation.
As a matter of fact, I suspect that recent min wage increase by feds is an attempt to induce inflation. All this money are going to be spent - basically creating larger money supply in consumer sector, and, maybe finally inducing some inflation feds are trying to start since 2008. Look at priced tags of recent tech acquisitions - some sectors of economy already value money much less than consumer sector.
Competition across sectors example is land lord can ask for a 10% increase, but the renter is totally free to say forget it and downsize to a rental at the original rental rate, while buying a xbox or whatever with the new income. Or paying off that .edu loan. Or paying for healthcare. Or whatever. Mandatory expenses like healthcare, tuition, iDevices, they're free to go up as high as they want and probably will. Most things are not mandatory.
Price compression is the $10M skyscraper penthouse isn't going to change because its a rounding error, but this could have a huge effect in a slumlord area. Where I live is in between, I already make about 3x median household income so going to 3.5 or so isn't going to change much.
Competition.
If you give money to me and the people bidding against me, the money will end up in landlords' pockets for sure.
Is it fair for me to think that universal basic income, if it has any chance of achieving its stated goals, is insufficient by itself at least when expressed as "give every living adult $x/yr" and nothing else? Now if the only effect of UBI is making a new $0 baseline and nothing else being changed on average, then it can't hurt that much by itself, so it may be worth trying in a limited area (such as a smaller country like the mentioned Switzerland) just to get an experimental result on record before trying it out on an economy the size of the US. But when you have to do all this other stuff to make UBI achieve its goals, like have the government build housing (it already does and has done that... http://en.wikipedia.org/wiki/Cabrini%E2%80%93Green), it makes me wonder why even bother with UBI itself and instead just get busy with the other things.