In no particular order:

Local authorities/Govt (since Thatcher) unwilling to build despite there being plenty of land available.
Becoming pregnant = new home.
Growing population.
The financial services.
Ridiculous restrictions should you ever get planning permission.
Capitalism in general.
NIMBY's.

That's about it for the mo.

You are sadly mistaken Tux.

There is plenty of agricultural land/flood plain/moors/forest etc.

Would you build on all that just to accommodate more and more people flocking here to make a better life for themselves but in the process making the UK (and the South East in particular an overcrowded hell hole like Dhakar in Bangladesh where 100's share a toilet and life is miserable with large families living in one room?

It's not the idea of living conditions I want to see for future generations, but that is inevitably what life will become unless we halt it now.

Controlling immigration is the most sensible and easiest solution to the housing crisis.

Unless we bring in euthanasia the ageing population will continue to be a problem.

Building more homes, means building more schools, hospitals etc and we do not have spare land without building on farmland/floodplain or other unsuitable land like beaches, forest, moors or marshland.

The left want more immigrants to come because they believe they will vote Labour.... there cannot be any other logical explanation.

It's easy to build when you know the right people.

"A planning application has already been submitted to develop the Kenley officers’ mess, which is within sight of the Croydon-Tandridge boundary and falls within the airfield’s conservation area as one of the country’s last remaining, intact Battle of Britain airfields.

"The Grade II-listed Officers’ Mess at Kenley airfield was all-but destroyed by fire last night.
Coincidentally, the two-storey building was subject to a planning application" Hmmmmmm

And Even good old Mr Noades from beyond the grave is looking to make a buck or two.

"A number of green belt sites in Tandridge have been identified as potentially ‘developable’ after five years, including Surrey National Golf Course (Owned by RN), with an Estimated Site Yield of 1,076 homes, Although Chaldon only occupies 1.9% of the total Tandridge area, 1,300 new houses equates to 13.6% of the 9,400 TDC needs to provide to meet government
targets.

And Tandridge's reply:

This first draft local plan consultation does not include any plans to build houses in the Green Belt. It does contain, for consultation purposes, sites in the Green Belt which have been put forward for development by land owners. The Council has reached no conclusions about whether any land should be released from the Green Belt and has not said housing should be built in those areas. The land at the Surrey National Golf Club, which you refer to, has been put forward by the land owner and the Council has made no decision about whether this Green Belt land should be released for development.

The aim of the final Local Plan, is to set out the vision for the district for the next 20 years and provide a framework for the future improvement, development and local protection of the area and Green Belt.