Apparently, very little work was done on the actual house following the death of old Mr. Radley in Harper Lee's To Kill a Mockingbird. The house was the worst on the block: the shingles "drooped over the eaves of the veranda" and weeds grew in the yard. His son did cement the knothold of the oak where the children found their gifts. It was thought that Mr. Radley's death might produce the sight of Boo, but Boo was never seen.
A few changes were seen when it became known that old Mr. Radley was dying. Sawhorses were placed at each end of the property to block traffic, which was "diverted to the back street." The sidewalk was covered in straw, and the doctor parked his car in front of the Finch house and walked to the Radley house. The sawhorses were taken down after Mr. Radley died.
The text informs us that:
The neighborhood thought when Mr. Radley went under Boo would come out, but it had another think coming: Boo’s elder brother returned from Pensacola and took Mr. Radley’s place. The only difference between him and his father was their ages.
The extract makes it clear that after Mr Radley's death, things at the Radley place pretty much remained the same. Even though the place was now run by Boo's elder brother, he maintained the status quo. This means that Boo could still not leave the house at his pleasure and that the dark and foreboding atmosphere that permeated the place remained.
In a physical sense, no alterations were made to the house either. The house still remained as closed and secretive as it had always been. One real difference, Scout noted, was that Mr Nathan Radley, Boo's older brother, would, unlike his father, actually speak to them whenever they encountered each other. The older Radley used to only cough in reply whenever they met and greeted him on the street.
It is both sad and ironic that Nathan did not make any changes to their place. It seems that he embraced all his father's quirks and did not adopt a more liberal and open policy. One would expect that he would have been more generous to his brother and that he would have made some attempt at sprucing up their house, since he was of a different generation. Clearly, though, this was not going to happen anytime soon.
Boo/Arthur's brother (Nathan) came to look after him.