The St John's Wood home occupied by Britain's previous three chief rabbis has been vacant for nearly a year, with Chief Rabbi Mirvis having opted for Hendon instead.
But the impressive period residence has recently acquired a new tenant - Rabbi Joseph Dweck, the senior rabbi of the Spanish and Portuguese Jews' Congregation, who will be installed into office on Sunday week.
It is not a Sephardi takeover of the Chief Rabbinate, he laughs. He, his wife Margalit and four of their five children - the eldest is studying in Israel pre-university - hope to move into their permanent residence this month.
Since his appointment last year, the Los Angeles-born rabbi, who is 39, was commuting monthly to London before settling here in July. The near-unanimous approval of his recruitment - a miracle in itself in synagogue affairs - helped to heal splits among Britain's oldest congregation.
"It's not the first time the Spanish and Portuguese Jews' Congregation has had a crossroads and they managed to pull through for three and a half centuries.
"It's not a small feat," he said. "It has a fantastic culture and philosophy."
While firmly rooted in the West, Rabbi Dwek has deep connections with the Middle East. His America-born parents are both of Syrian lineage and his mother's family were among the first Syrian Jews to reach the United States in 1901. The foremost modern Sephardi leader, Rabbi Ovadia Yosef, used to stay with Rabbi Dwek's grandfather in Los Angeles.
For two years after Jewish high school, Rabbi Dweck studied at a new yeshivah in Israel founded by Rabbi Yosef's son, Yitzchak, who is now Israel's Sephardi Chief Rabbi.
"At 20, I told him I thought it was time to continue my education - I never intended to go into the rabbinate, I intended to go into psychology. He said I'd really like you to meet someone first," said Rabbi Dwek
That someone was Margalit, Rabbi Yitzchak's niece and Rabbi Ovadia's granddaughter.
But the couple went to live in the US where he pursued both secular and Jewish studies. Offered a part-time post as a chazan at a new Sephardi congregation Shaarei Shalom in New York, he later became its rabbi, expanding it from 50 members to 350 families in 15 years. He also headed an elementary Jewish day school for the past four years.
He was "taken aback" to get the call from London. But he believes the post will give him a broader platform than his previous position, where "there wasn't a great deal of branching out to the greater Jewish world".
He has already opened a Twitter account for the S and P, and a Facebook page will follow. A programmes manager has been hired. "We are working on doing some events for professionals in the city and having Bevis Marks [the Sephardi showpiece synagogue in the City of London] as a centre," he said.
And he will maintain a busy teaching schedule. "My experience is people enjoy learning and discovery when it is relevant to their lives," he said. "I am a big believer that the Torah is not just an abstract religious list of laws that are there to intrude on your lives. It is a very human-oriented system and it's something we can express and teach that way."
He is still adjusting to Anglo-Jewish ways but wonders if we are prone to keep our heads down too much. Everyone who has driven him past the JW3 centre has remarked on how prominent it was.
"In a democratic country, where the Jewish community has always done a great deal to support the city and country they are living in, it is interesting that there would still be this feeling of self-consciousness that we have built a Jewish centre we are concerned is a bit too prominent across the road."
