The news that so-called boomerang children are costing older homeowners an average of £3,400 a year will resonate in households across the country. Key Equity Release has crunched the numbers and found that rising numbers of adult offspring who return to or never leave the family home are placing a measurable financial strain on their parents’ budgets, from higher grocery bills to increased energy usage.
Beyond the immediate household ledger, this trend also raises questions about space. A grown-up child staying put often means a bedroom that cannot be turned into a study, a dining room that never quite becomes a downstairs guest suite, or a loft conversion that keeps getting postponed. The financial cost is only one dimension; the pressure on square footage is another, and it is not evenly spread across the country.
Where younger residents already fill the postcode
| District | Post town | Region | Under 18 |
|---|---|---|---|
| S98 | Sheffield | Yorkshire and The Humber | 32.2% |
| B9 | Birmingham | West Midlands | 30.6% |
| B25 | Birmingham | West Midlands | 29.3% |
| B8 | Birmingham | West Midlands | 29.3% |
| BD3 | Bradford | Yorkshire and The Humber | 29.1% |
| BD5 | Bradford | Yorkshire and The Humber | 28.8% |
| B19 | Birmingham | West Midlands | 28.4% |
| B10 | Birmingham | West Midlands | 28.3% |
| M7 | Salford | North West | 28.3% |
| S4 | Sheffield | Yorkshire and The Humber | 28.0% |
Our own data at Postcodes UK paints a picture of districts where homes have long been oriented around younger occupants. The postcode district with the highest proportion of residents under 18 is S98 in Sheffield, where 32.2% of the population falls into that age bracket. In a district like this, the concept of a ‘boomerang’ return is almost baked into the housing stock. These are streets where family-sised properties were built for multiple generations or large households, and the local infrastructure, from schools to play parks, reflects that.
When an adult child remains in or returns to a postcode such as S98, the financial pressure identified by Key Equity Release is layered onto an existing reality: the house was likely already operating at something close to its intended capacity. There is less slack in the system. A spare room may never have existed in the first place, meaning the £3,400 annual cost is not just about pounds and pence but about a home that was never designed to absorb an extra adult long-term.
When the data and the household budget collide
The Key findings give a national average, but the local picture matters enormously. In a postcode district where under-18s make up nearly a third of residents, the dynamics of a boomerang child are different from those in an area dominated by retirees or single-person households. The financial hit lands in a home that may already have a full fridge, a busy bathroom rota, and heating on for longer because more people are simply living there. The £3,400 figure could easily be an underestimate in a district like S98, where household sises are structurally larger.
For older homeowners considering equity release to manage these costs, the postcode context is critical. A property in a district with a high proportion of young people may hold its value differently, and the decision to release equity to fund an adult child’s living expenses needs to be weighed against the long-term value of a family-sised home in an area where demand for such properties is persistent. The boomerang effect is not just a personal finance story; it is a postcode story.
The data behind this
The financial impact of boomerang children was reported by Mortgage Solutions, citing analysis from Key Equity Release. The postcode district population statistics are sourced from the Office for National Statistics census data, accessed via the Postcodes UK database, with supplementary property context drawn from HM Land Registry records held within our own systems.
In response to reporting by Mortgage Solutions. Analysis and figures by Postcodes UK.