Question: What happens during isolation - at what point is it acceptable to leave the house if no symptoms have appeared?

Answer passage (source: UK):
page_title: Guidance Staying alert and safe (social distancing)
section_headers: Staying at home
section_content: It is still very important that people stay home unless necessary to go out
for specific reasons set out in
law. These include:

for work, where you cannot work from home
going to shops that are permitted to be open – to get things like food and medicine, and to collect goods ordered online or on the phone
to exercise or spend time outdoors for recreation
any medical need, to donate blood, avoid injury or illness, escape risk of harm, or to provide care or to help a vulnerable person

Where parents or someone with parental responsibility do not live in the same
household, children under 18 can be moved between their parents’ homes to
continue existing arrangements for access and contact.
The government has also identified a number of critical
workers whose children can
still go to school or their childcare provider. This critical worker
definition does not affect whether or not you can travel to work - if you are
not a critical worker, you may still travel to work if you cannot work from
home. However, if you, or a member of your household are unwell with symptoms
of coronavirus, you should isolate and should not travel to or attend the
workplace.
Critical workers and parents or guardians of vulnerable children may leave
their home to take children to and from school or their childcare provider.
You can also attend the funeral of a close family member or member of your
household (or, of a friend, if no one from their close family or household is
attending). Religious ministers or leaders can leave their homes to go to
their place of worship, but these should remain closed to the public
You may also leave or be outside of your home in order to access other
critical public services, such as social services, support provided to
victims, services provided by the Department for Work and Pensions, to fulfil
a legal obligation, or to move home in line with the government’s
guidance.
A fuller list of the reasons you can leave home is set out in the
regulations.
When you do need to go out, you should follow the guidelines on staying safe
outside your home. Most importantly, this includes the key advice that you
should stay two metres apart from anyone outside of your household. Face
coverings can help us protect each other and reduce the spread of
the disease if you are in an enclosed space where social distancing isn’t
possible and where you will come into contact with people you do not normally
meet. This is most relevant for short periods indoors in crowded areas, for
example on public transport or in some shops. You should be prepared to remove
your face covering if asked to do so by police officers and staff for the
purposes of identification.
It is still not permitted to leave your house to visit friends and family in
their home. The government is looking at how to facilitate greater contact
with close family or friends, and will explain how this can be done safely in
the coming weeks.
By following this guidance, you are helping to protect yourself, your family,
the NHS and your community.
Further guidance on the mental health and wellbeing aspects of coronavirus
(COVID-19) has been issued.

Reviewer feedback on this answer:
This does not answer the question. The question is asking for information on isolation and this answer provides information on what activities are allowed and prohibited during covid-19 stay at home order.
The question asks about how long to stay isolated if you've been exposed to the virus, but the answer is about general rules during the pandemic.
Not only does this describe how to stay safe but it outline jobs that might be at risk of this virus

Reviewer ratings:
Bad
Bad
Excellent