"Instead of government telling people to work from home, we're going to give employers more discretion and ask them to make decisions about how their staff can work safely", Johnson said.
"We will pilot larger gatherings in venues such as sports stadia with a view to a wider reopening in the autumn", he said at a Downing Street briefing.
Widespread use of public transport is now allowed in England, but passengers must use face coverings or face fines.
Johnson concluded that normal life may be able to resume in full from November at the earliest, "possibly in time for Christmas".
In response to a question from the public, the PM said it "may conceivably be possible" to depart from social distancing measures "by November at the earliest".
Stadium capacities will still be restricted and staggered entry times, social distancing measures and one-way systems will be required.
Bowling alleys, skating rinks, casinos and beauticians are also set to reopen on August 1, but nightclubs and soft play areas will remain closed, but under review.
The prime minister said: "From tomorrow, local authorities will have new powers in their areas".
"If their employer, the school, tells them they shouldn't come into work because they can't work in a safe and Covid-secure way, then he doesn't have to go into work. And it's certain that the NHS will face the usual annual winter pressures", he warned. "I can confirm that we're providing an additional £3 billion [$3.7 billion] of funding for the NHS in England to get ready for winter", he said.
Johnson announced that the government would roll out the "biggest ever flu vaccination programme in the history of the UK".
London mayor Sadiq Khan quickly raised concerns over the move to encourage staff back to workplaces, warning Tubes in the capital can not be allowed to become "packed" again.
Johnson stressed his return-to-work plan is cautious. Some homes are not good places to work from.
Even Mr Johnson conceded the United Kingdom could be hit by a second wave, stating: "Demand for testing is not the only challenge that winter will bring".
Vallance warned on Thursday that cases are likely to increase again in the winter and "it's quite probable that we will see this virus coming back in different waves over a number of years".
- Welsh First Minister Mark Drakeford said his advice to workers in Wales remained to "stay at home and work from home" if they are able to do so.
Meanwhile, Health Secretary Matt Hancock announced he wanted an urgent review into the death toll data from Public Health England, after researchers revealed that a "statistical anomaly" meant "no one can recover from COVID-19 in England".
Fears of a second wave of infections were raised this week when scientists said almost 120,000 people could die in hospitals alone from September to June next year.