Harry Rutter opens our interview by making a seemingly obvious point: tackling homelessness is nothing like treating an infection. For the latter, a simple antibiotic will usually work, says the professor of public health at the University of Bath.

But the effort to end the relentless rise of people experiencing homelessness? “That’s not so simple,” he says. “The homelessness system is huge, messy, and complex. There’s not just one thing you need to do.”

Getting to grips with complexity is a key skill in Prof Rutter’s public health discipline. He’s used it to tackle childhood obesity and knife crime, and is now bringing it to bear on homelessness and rough sleeping as a member of a new expert advisory group.

Formed of internationally renowned academics and professionals, the group is steering an ambitious project being co-ordinated by the Centre for Homelessness Impact (CHI), a What Works Centre. The project is funded with £15m from the Ministry of Housing, Communities, and Local Government and has been described as “ground breaking” by its director of analysis and data, Stephen Aldridge.

Over the next 18 months, the project will evaluate eight interventions to tackle rough sleeping and homelessness in councils across England, including the Health Outreach Project.

But it will also draw back and take a more sweeping view of homelessness and rough sleeping, through conducting a Systems-wide Evaluation. This aims to map out the mesh of interventions and services which make up the rough sleeping and homelessness system, assess existing evidence, better understand the drivers, and crucially, gather new evidence through fieldwork with local areas, local, regional and national government and people with lived experience. The system mapping will help pinpoint any skews, biases, or gaps in the evidence needed to make the system improve.

Prof Rutter says the evaluation is “forward-thinking” and has already highlighted bias in the system. “In homelessness, there is a big focus on rough sleeping and short-term measures to get people off the streets but much less attention paid to how people get support coming out of care, prison or other institutions,” Prof Rutter says. “The evidence base tends to reflect where attention is placed so if you just ask: what does the evidence base tell you is the problem? – you can be misdirected because it tends to reflect things on which there is policy, funding and attention.” 

Besides public health, the advisory group includes experts in psychology, housing, homelessness, and in the evaluation of publicly funded projects.

Group member Peter Mackie is Director of Impact and Engagement at Cardiff University, where he is described as a leading international expert in housing and homelessness. He hopes evaluations of the Test and Learn projects will fill “gaps” in our understanding of how well some homelessness interventions work. “As academics, we do a lot of telling people what the challenges are and stop there; we don’t do solutions,” he says.

To fill these gaps, each Test and Learn project will be evaluated using rigorous scientific trials, techniques which are frequently used in healthcare and homelessness research in the US but not in the UK. “The project’s approach to evaluations is such a new departure from the way that we have previously studied homelessness,” Prof Mackie says.

The hope of CHI and its expert advisory group is that these new evaluative techniques will generate stronger evidence to justify the expenditure of public money on homelessness interventions. The Systems-wide Evaluation will show how interventions interact and work together as a whole.

To help with this endeavour, the advisory group includes Rebecca Pritchard, a member with extensive experience in running and commissioning services. Ms Pritchard began her career in the late 1980s as a volunteer, lugging furniture up staircases for the Southampton Resettlement Project. Since then, she’s held senior positions in housing, homelessness, and care bodies, and advised the national Government on youth homelessness and rough sleeping.

Her hope for the “very rigorously evaluated” Test and Learn projects is that they will become “orthodox” interventions which fellow professionals can commission and run with confidence nationwide.

As a former Government adviser, Ms Pritchard understands the pressures to balance the “costs” and “benefits” of services as well as their books. She hopes the Systems-wide Evaluation will give officials and ministers the evidence they need to fund new services, make savings in others, and understand any “knock-on effects” of planned cuts.

As in any complex “messy” system, the impact of changes are not often as clear as its ultimate aim. In this case: to end rough sleeping and homelessness. 

“It might be that if you help someone in one part of the system it will make savings elsewhere. But that won’t always be the case,” Ms Pritchard says. “If you bring someone off the streets they will start to use services, claim benefits and that costs,” she adds. “Doing the right thing doesn’t always save money.”

A full list of members of the expert advisers’ group is available on our website here.

Keith Cooper is a freelance journalist