"I want to reflect on the election and why it did not deliver the result I hoped for".
The seat, held by Minister for London Gavin Barwell, is the most marginal Tory constituency in the capital.
She accredited the victory to young people and the role played by Labour leader Jeremy Corbyn.
On Friday morning, the BBC reported that prime minister Theresa May has "no intention of resigning". "I look forward to working with him".
Nick Leeming, chairman of Jackson-Stops & Staff, said: "With Gavin Barwell gone, it will be interesting to see what happens to the long awaited Housing White Paper that disappeared from the scene since its publication in February".
May's office has already said that the senior Cabinet members - Treasury chief Philip Hammond, Foreign Secretary Boris Johnson and Home Secretary Amber Rudd - will keep their current jobs, but she is expected to reshuffle the lower ranks of ministers.
Questions now remain over the future of the prime minister.
Barwell received 24,221 votes while Labour candidate Sarah Jones got 29,873, giving her a 6,652 majority.
The Conservative Party has also now reached a "confidence and supply" agreement with the Democratic Unionist Party that will allow them to form a government.