"The Adventure of the Norwood Builder" is one of the 56 short Sherlock Holmes stories written by Sir Arthur Conan Doyle. It is the second tale from The Return of Sherlock Holmes. The story was first published in The Strand Magazine in 1903 with original illustrations by Sidney Paget.
Sherlock Holmes and Dr Watson are visited by "the unhappy John Hector McFarlane", a young lawyer from Blackheath who has been accused of murdering one of his clients, a builder called Jonas Oldacre. McFarlane explains to Holmes that Oldacre had come to his office only the day before and asked him to draw up his will in legally appropriate terms. McFarlane saw to his surprise that Oldacre was making him the sole beneficiary, and heir to a considerable bequest at that. McFarlane could not imagine why, although Oldacre claimed that it was due to a prior relationship with McFarlane's mother, which gave him reliable knowledge that McFarlane could be trusted, and a lack of any biological relatives for him to leave his assets to.
This business took McFarlane to Oldacre's house in Norwood, where some documents had to be examined for legal purposes. These were kept in the safe of the room where the murder allegedly took place. McFarlane left quite late and stayed at a local inn. He read about the murder in the newspaper the next morning on the train. The paper said quite clearly that the police were looking for him.
The evidence against young Mr McFarlane is quite damning. His stick has been found in Mr Oldacre's room, and a fire was extinguished just outside in which a pile of dry timber burnt to ashes, complete with the smell of burnt flesh. It seems more than likely that McFarlane committed the crime, especially as it is known that he was present at the scene at about that time.
Inspector Lestrade does quite a bit of gloating in this story, for it seems that he is on the right track and Holmes is not. Holmes begins his own investigation into the matter by going to Blackheath, which puzzles Lestrade, who had expected him to go first to Norwood. Although he acquires some useful information in both places, he must admit that he can see no other explanation for what has happened to Mr Oldacre than the official one propounded by Lestrade.
McFarlane's mother, Holmes finds out, was once engaged to Oldacre years earlier, but then later wanted nothing to do with the man once she found out how cruel he was—he had let a cat loose in a bird sanctuary.
Upon examining the handwritten will given McFarlane by Oldacre, Holmes reckons it was written in a very haphazard fashion, as if the writer didn't really care what he was writing. The alternation between legible handwriting and incomprehensible squiggles suggests to Holmes that the "will" was written hurriedly on a train, with the legible writing representing stops at stations. All Holmes can offer as an alternative are general theories, while Lestrade parries with the knowledge that none of the papers were taken, and that only McFarlane, if Oldacre were murdered, would not have any reason to take the papers.
It also emerges that Oldacre's financial dealings have been a bit odd. Several cheques for substantial amounts, and for unknown reasons, have recently been made out to a Mr Cornelius.
The discovery by Holmes of Mr Oldacre's trouser buttons in the fire ashes does nothing to help exonerate McFarlane, but Holmes is convinced that Mr Oldacre's housekeeper is withholding information. Holmes's powers of observation tell him that the housekeeper's expression suggests this. He is sure that she holds the key to the mystery, and he is right, but he will not need her to solve the case.
Lestrade's gloating reaches a peak when a bloody thumbprint is found at Oldacre's house. He is sure it is enough to put McFarlane's neck in the noose. It matches the accused's thumb exactly. However, it makes Holmes quite sure that something very devious is afoot: Holmes examined that part of the house only a day earlier, and is quite sure that the thumbprint was not there then, and McFarlane has been in police custody since his arrest at Holmes's Baker Street rooms. So, someone is attempting a deception.
Once again, Holmes astonishes Lestrade with his unorthodox methods, which in this case involve setting a fire in one room of the house with a little straw (with a man standing by with a bucket of water) and having three of his constables shout "fire". Lestrade, and Watson too, are also quite astonished at what happens next: the very much still-living Mr Oldacre emerges from a hidden chamber at the end of a hallway—where Holmes has deduced it must be—and runs to escape the fire. He is seized, protesting.
The dénouement reveals that it was a revenge campaign against the woman who rejected him years ago, young Mr McFarlane's mother. Pathetically, Oldacre tries to pass off his actions as a practical joke, but he is taken into custody. Holmes lightly ribs his rival for neglecting Blackheath, where he acquired the key information.
As for Mr Cornelius, the recipient of so much of Oldacre's munificence, Holmes deduces that it is likely an alias used by Oldacre, and that he has been leading a double life with the eventual goal of shedding his Oldacre identity so that he can start a new life. "The banking account of Mr Cornelius" will be seized by Oldacre's creditors. Oldacre swears revenge against Holmes, who serenely dismisses the villain's threats.
Sir Arthur Conan Doyle lived in Norwood, and included some local details into the story. For example, McFarlane spends the night in The Anerley Arms, a pub which existed as of 2011, but had a derelict upper floor (no more overnight guests) and changing management.
It is one of the few Holmes stories in which a fingerprint provides a good clue to the nature of the problem. The wax thumb-print reproduction idea was devised by, and bought from, Bertram Fletcher Robinson (1870–1907), who also helped plot The Hound of the Baskervilles (1901). 
At the start of the story, Watson mentions two unrecorded cases that Holmes investigated around the same time as this story:
- "The case of the papers of Ex-President Murillo", which Conan Doyle later wrote as "The Adventure of Wisteria Lodge".
- "The shocking affair of the Dutch steamship Friesland", which loosely inspired the 1945 film Pursuit to Algiers starring Basil Rathbone as Holmes.
The Granada TV version with Jeremy Brett was faithful to the original story with exceptions. On TV, Oldacre kills and burns a tramp, versus in Doyle, he refuses to admit what flesh burned. Mrs McFarlane is a recent widow, versus Mr McFarlane is alive but away. Watson traces payments to Cornelius, versus Holmes gleans this fact. Holmes warns McFarlane his words may be used against him versus Lestrade.
In the BBC radio adaptation starring Clive Merrison as Holmes and Michael Williams as Watson, because of his change of attitude towards fame (acquired while travelng in Tibet during his "death"), Holmes at the beginning informs Watson that "there must be no more stories", but that Watson should continue to keep notes on their cases so as to stockpile them for possible future publication. Also, after his capture Oldacre reveals that he also believed Holmes to be dead.