The book is about three families in England at the beginning of the 20th century: the Wilcoxes, rich capitalists with a fortune made in the Colonies; the half-German Schlegel siblings (Margaret, Tibby, and Helen), who have much in common with the real-life Bloomsbury Group; and the Basts, a struggling couple in the lower-middle class. The Schlegel sisters try to help the poor Basts and try to make the Wilcoxes less prejudiced.
The Schlegels frequently encounter the Wilcoxes. The youngest, Helen, is for a short period intensely attracted to the younger Wilcox brother, Paul; each rejects the other for his or her own reasons. The eldest, Margaret, becomes friends with Pauls mother, Ruth Wilcox. Ruths most prized personal possession is her family house at Howards End. She wishes that Margaret could live there, as she feels that it might be in good hands with her. Ruths own husband and children do not value the house and its rich history, because such abstractions, while being very dear to Margaret, are lost to them. As Ruth is terminally ill, and Margaret and her family are about to be evicted from their London home by a developer, Ruth bequeaths the cottage to Margaret in a handwritten note delivered to her husband from the nursing home where she has died, causing great consternation among the Wilcoxes. Mrs Wilcoxs widowed husband, Henry, and his children burn the note without telling Margaret about her inheritance. However, over the course of several years, Margaret becomes friends with Henry Wilcox and eventually marries him. The more free-spirited Margaret tries to get Henry to open up more, to little effect. Henrys elder son Charles and his wife try to keep Margaret from taking possession of Howards End.
Gradually, Margaret becomes aware of Henrys dismissive attitude towards the lower classes. On Henrys advice, Helen tells Leonard Bast to quit his respectable job as a clerk at an insurance company, because the company stands outside a protective group of companies and thus is vulnerable to failure. A few weeks later, Henry carelessly reverses his opinion, having entirely forgotten about Bast, but it is too late, and Bast has lost his tenuous hold on financial solvency. Bast lives with a troubled,fallen" woman for whom he feels responsible and whom he eventually marries. Helen continues to try to help young Leonard Bast (perhaps in part out of guilt about having intervened in his life to begin with, as Leonard had not wanted it and Henry had explicitly stated beforehand that he advised no one) but it all goes terribly wrong; because of Basts wifes connection with Henry, Henry will not countenance helping them. It is later revealed that 10 years previously, as a teenager, she had been Henrys mistress in Cyprus, but he had then carelessly abandoned her, an expatriate English girl on foreign soil with no way to return home. Margaret confronts Henry about his ill-treatment, and he is ashamed of the affair but unrepentant about his harsh treatment of her. Because of Margarets impending marriage into the Wilcoxes and situations such as these, the Schlegel sisters drift apart somewhat. In a moment of pity for the poor, doomed Bast, Helen has an affair with him.

Includes a biography of the Author