At present politicians of all parties are sticking their heads in the sand and hoping the housing crisis will go away. It won't.
This is about physical numbers of people and an ever ballooning population exponentially growing. This is about personal responsibility and not just the responsibility of the Government of the day. Is it responsible to have families with large numbers of children and expect someone else to find space to house them all? Overpopulation is the biggest cause of global warming - our human impact on the limited land mass that we live on, land that we share with other wildlife and plants, trees etc. At present every time we build houses we seal over a land mass and create even greater flood risk from storm run off.
We need a creative and collective community house building programme with self contained, eco pods or flats. A house building project where the Government does not have to fund it because Govt has no public money to fund capital projects. One where we don't borrow any more money to fund housing that people are paid to live in, for minimal returns. But we do need to get those people wanting housing to become engaged in and to have a vested interest in the home that they occupy. Members of each family need to build their own homes (and grow their own food) Those homes need to be made in a secure enclosures with gardens, allotments, play areas and leisure facilities such as a swimming pool. We do need to get the families who intend to live in the new builds to contribute to their environment, and under a bond of expectation. Anyone who is unruly or destructive would be moved and be housed elsewhere. The benefits would be that people could have an affordable and pleasant place to live.
A little like the building of the old council housing estates. Old disused properties in undesirable areas need to be purchased by Government and refurbished with the help of prospective tenants into reasonable housing. Developers will not build social housing on new build estates because it is too expensive to do so. Developers often perceive they will lose money from private builds right next door to housing social families but they could help transform forgotten and abandoned buildings for local homeless people.
The housing crisis has been looming for a long time with chronic underfunding and a lack of house building. The trend to pay private Landlords housing benefit payments wastes so much money and is likely corrupt. The Government has abdicated responsibility for social housing and they have used hotels and private landlords to accommodate homeless and low income residents. When residents fail to pay rent they have eventually been evicted and have ended up on the council emergency housing door. Councils have no available housing or money. Governments have passed legislation making it extremely difficult for a private landlord to evict a tenant who only makes sporadic rent payments. Legislation requiring costly licences, fire equipment and other structures to be fitted in small tenanted properties have wiped out any incentive for private landlords to now offer rental accommodation. Landlords are selling up and will no longer be a social housing prop. This is an ever growing crisis.
The birth rate rose significantly post 2000 following a large and continued influx of immigration. Continuing to accept large numbers of people into a finite space where there are insufficient houses and other infrastructure does not help the housing crisis in any way. The UK land mass is full and we need to accept that. We have to keep a vision of how we want the over population of the UK to be for our future generations. When we cannot house our own homeless indigenous population it is reckless to keep accepting and inviting more and more people to live here, expecting them to be housed and supported on the assumption that the 'tax payer' will keep funding it.
So in answer to your question: -Immigration is not the sole cause of the housing crisis but it has highlighted policy failings