Sell and Buy houses from bank in the same round?

Question

Can I sell a house from a property that I own and buy it in the same round from the bank again ?

This question is an edge case of What happens when you need to tear-down a hotel but no houses are in the bank in Monopoly?

Answer 1

From the current rules at Hasbro, under the Selling Property section (emphasis mine):

Houses and hotels may be sold back to the Bank at any time for one-half the price paid for them.

And then from the Houses section (emphasis mine again):

When you own all the properties in a color-group you may buy houses from the Bank and erect them on those properties. If you buy one house, you may put it on any one of those properties. The next house you buy must be erected on one of the unimproved properties of this or any other complete color-group you may own.

The price you must pay the Bank for each house is shown on your Title Deed card for the property on which you erect the house. The owner still collects double rent from an opponent who lands on the unimproved properties of his/her complete color-group.

Following the above rules, you may buy and erect at any time as many houses as your judgement and financial standing will allow.

So I see no reason why you couldn't sell a house and buy it back again in the same round. Just remember that you have to sell houses evenly as well.

Answer 2

Yes, you can and it is often a good stategic move if you can create and control a housing shortage.
For example:
You buy the remaining houses for your light blue color group.
Once you have available funds you would prefer to sell these houses (or buy up to Hotel if possible)
and immediately buy the available houses for your dark blue group.
But if others also wish to buy houses at this point, there is the following rule:
[in a building shortage] players wish to buy more than the Bank has,
the buildings must be sold at auction to the highest bidder.