The housing crisis is one of the defining issues of our time. And for that reason, I chose to join Shelter’s social housing commission.

For a generation our country hasn’t been building enough homes, ownership is in decline and the price of renting in the private sector is punishing. Earlier this summer our commission reported that nearly half of all homeless families are actually in work. A job no longer guarantees you a roof over your head in Britain in 2018.

In 1945, when Britain faced its worst housing shortage of the 20th century, it was clear that a big programme of public housebuilding was needed to alleviate the wartime devastation of housing and pave the way for economic and social success.

The sweeping changes introduced by the government worked. Homes were built and offered to those who needed them. Nye Bevan oversaw a revolution in both the NHS and housing, and the radical policies of that postwar period became the conventional wisdom of both main parties. Housing was a large part of the successes of the 1950s and 1960s.

As home ownership took off, the conventional wisdom gradually changed. The market would provide. Governments of all persuasions forgot the true value of large-scale investment in bricks and mortar and abdicated much of the responsibility for housebuilding, including low-cost housebuilding, to private developers.

As the Letwin Review recently concluded, the whole system of housebuilding in this country keeps prices high, and ordinary people on lower incomes permanently shut out of home ownership. And with fewer social homes built in the past decade than we managed in just one of those postwar years, millions have nowhere to turn to for a home but the private rental sector.

But oversubscribed and poorly regulated private renting is so often not up to scratch. Short-term tenancies mean that tenants might plant trees in their garden but won’t be around long enough to see them grow. Or they might endure mould or vermin if they fear their landlord would sooner replace them than address the problem.

Moreover, private rents are just too expensive. The long-standing government solution to this is to top up people’s income with housing benefit. But this has resulted in the cost of housing benefit rising to tens of billions of pounds a year – a subsidy to landlords, not an investment in the country’s future. All the while, the leading cause of homelessness is still the loss of a private tenancy.

Meanwhile, social housing was sold off and not replaced. As a result, it has tended to become the domain only of the very neediest. From being seen as aspirational in its original inception, as well as a place of safety and security, social housing is often seen as something to be avoided.

As part of the commission’s work, I recently had the privilege of attending a citizen’s jury in Doncaster, where local social tenants got together with private renters to discuss the future of social housing. The overwhelming sense was that power lay elsewhere – with the private landlord or the social housing provider, never with them. People rightly wanted to have the power to be heard, to get repairs done promptly, to have decent homes at prices they could afford.

The tentacles of this crisis are far-reaching – whether it’s the low-income couple putting off having children because of the cost of housing, teachers who cannot afford to live in our cities, leaving schools short staffed, or young professionals living in miserable and sometimes dangerous conditions trying in vain to save up for a deposit.

In recognition of the scale of the challenge, Shelter’s social housing commission is cross-party, involving grassroots campaigners, including from Grenfell Tower, and is drawing on a wide range of expertise. It will produce concrete recommendations in the coming months, but it is already apparent that we need a renewed vision for housing the British public, appropriate for the 21st century but learning from the past. In 1947, Bevan emphasised the role housing played in building strong, vibrant communities. “We should try to introduce in our modern villages what was always the lovely feature of English and Welsh villages, where the doctor, the grocer, the butcher and farm labourer all lived in the same street. I believe that is essential for the full life of a citizen.”

The world is very different now but as in Bevan’s vision 70 years ago, we need to think of housing as a building block of our communities. And the market alone simply cannot deliver homes either on that scale, nor with that vision in mind.

Housing needs to be seen again as a national asset, just like our transport infrastructure. The government is putting billions into projects such as HS2 and Crossrail. A fraction of that investment also invested in public housing would make a substantial contribution to the number of new homes we need.

Some people will argue that state investment in housing on this scale is unaffordable. But the value of homes cannot be measured just in pounds and pence, but rather in the quality of life lived by a country’s citizens. The human cost of not investing in social housing is not one we should be willing to pay.

The postwar period of social and economic success for our country was built on the pillar of public housing, and in post-Brexit Britain this should be something to aspire to once again. Our commission will seek to provide a new vision for public housing that works for this and future generations. A vision for every priced-out renter and reluctant commuter, low-income worker and sofa surfer. That vision is needed now more than ever.

Ed Miliband is a commissioner of Shelter’s Big Conversation on social housing.