A survey of about 1000 Kiwis has shown more than half of them have issues with their homes, including mould and dampness.
Of the 1002 people surveyed, 57 per cent said they had experienced mould, dampness and issues with heating and insulation.
Sixty-five per cent of those surveyed were under 35 and are living with one or more of the issues in their home.
The survey found renters were twice as likely to report the presence of mould (21 per cent) in comparison with homeowners (11 per cent).
Renters were also twice as likely to describe their homes as not being warm or dry, with inefficient lighting and heating (21 per cent), when compared to homeowners (five per cent).
Kiwi homes were described as being awash with condensation, with 37 per cent of people surveyed stating they regularly had it on their windows in winter.
Twenty-nine per cent said they needed to remove water from their windows daily.
The survey found 39 per cent of respondents were living with someone who had a respiratory illness, cardiovascular disease, or skin infection.
Twenty-two per cent of those surveyed live with someone who has asthma.
Those pre-existing conditions have been known to worsen in unhealthy home conditions.
Nik Gregg, co-founder of Sustainability Options — an organisation which works with the Ministry of Health's 'Healthy Homes Initiative' — said the survey's findings echoed what it saw every day.
"Sadly, children without beds, bedrooms at below 10 degrees, families sleeping in the lounge to stay warm, homes with damp carpets, mouldy curtains and draughty windows are all too common."
The survey also found 20 per cent of Wellingtonians had experienced mould, compared to 14 per cent of the whole population.
People in urban areas (17 per cent) said their homes were not dry, warm, safe or efficient, compared to five per cent of homeowners, and 10 per cent of the whole population, the survey found.
The survey was conducted in early May by PureProfile as part of The Warehouse's initiative, 'The Warmhouse' .