A series of subtle changes to housing benefit mean the safety net for people renting their home is shrinking fast

The necessity of housing makes housing benefit a crucial part of the safety net. It ensures that if someone loses their job, they don't immediately fall behind on their rent and risk losing their home as well. It also allows job-seekers to focus on securing a new job rather than where they are going to sleep that night.

Research by Shelter found that a quarter of UK workers responding to its survey had no savings at all and would immediately find themselves struggling to keep up with housing costs if they lost their job. If someone loses their job and needs support – as millions every year do – their home is no longer safe.

For tenants in the private rented sector, housing benefit provides money to help cover the rent. There are rightly conditions on what can be claimed. Entitlement is based on the number of rooms required (not the size of the property they live in) and the typical cost of renting in their area. But since 2011, the government has made a series of changes that have tightened these conditions much further.

The broadest change is a reduction in the maximum amount that can be claimed in housing benefit. Previously it was capped at the median rent for local properties (a rent level typical for that area). But in April 2011 the amount was changed to only be enough for the cheapest 30% of properties in the area.

For ministers this was an easy policy to justify: why should the state subsidise families with unnecessarily high housing costs? But in 136 of England's 326 local authorities more than 30% of private rented households claim housing benefit, making it impossible for everyone claiming to find accommodation. By comparison, only in eight local authority areas do more than half of private renters claim housing benefit, so the former cap meant the safety net could catch almost everyone in need of it.

There is another change coming too. At the moment the housing benefit caps only affect those making a new claim after 13 weeks. This means that when someone loses their job they still have that period of security in which to find a new job before worrying about finding a new home. But under the government's new benefits system, universal credit, this grace period will be withdrawn – and with many tenants having no significant savings, many would instantly find themselves struggling to pay rent.

This is just one of a number of recent changes to housing benefit that could affect private renters. The national housing benefit cap all but excludes claimants from much of inner London and failing to link increases in housing benefit with increases in local rent prices mean that, over time, fewer and fewer properties will be available.