Your neighbour's hedge may count against you

The last question in the interview would not be about weaknesses, five-year plans or the gap in 2027. It would be about the hedge. Under a household carbon budget that could be in force by 2030, the answer would be checked before the references.

Carbon footprint accounting has spread from companies to individuals: banks and apps now offer personal footprint tracking, and the idea of personal carbon allowances has been studied by researchers and governments for years. Corporate sustainability reporting increasingly covers indirect emissions, which include employee commuting and, in some frameworks, home working. Hedges and garden vegetation are counted as carbon storage and biodiversity assets in the planning rules of several countries, and hedge cutting is already restricted during the bird nesting season. Disputes over hedges and boundaries are among the most common neighbour complaints in suburban areas.

Under the scheme, every address would receive an annual allowance of emissions. Heating, travel and parcels would be charged against it, and anything growing on the plot would be credited to it, at rates set out in a table that gives a mature hawthorn hedge roughly the annual value of a medium-sized dog. Employers, obliged to report the emissions of the people who work for them, including their commutes and their kitchens on home-working days, would prefer candidates whose households ran a surplus. The question, in the wording circulated to recruiters, would read: describe the vegetation on your boundary and state who owns it.

The difficulty would be that most hedges belong to somebody else. Boundary vegetation would be credited to the address named on the title deed, so a candidate whose garden was enclosed on three sides by a neighbour's privet would, for budget purposes, be living in a car park. “I have a lawn,” Dean Whitlock would tell a panel for a logistics planning role. “The hedge is Mr Osei's. I water it, but it's his.” The panel would thank him for his candour and offer the job to a woman with a leylandii.

The draft guidance would allow a partial claim for overhang, defined as growth extending more than thirty centimetres across the boundary at a height of one metre, measured at the winter solstice. This would create a market in encouragement. Householders would be seen feeding a neighbour's hedge from their own side, reaching through with a hose, and in one case described in the consultation, fixing a mirror to the fence to draw the growth across. A ruling on whether a hedge that leans is being claimed or stolen would be expected in the second year. Trimming a neighbour's overhang, at present a courtesy, would become a transfer of assets.

Job offers would carry conditions. A regional water company's standard letter would make appointments subject to confirmation of vegetative standing, with a site visit where the stated hedge could not be located on the aerial survey. Tenants would be asked for a letter from the landlord confirming that the hedge passed with the tenancy. Priya Lindqvist, a trainee surveyor, would recall being asked at a second interview whether her partner's mother, who owned the hedge, intended to remain in good health. She would get the job on the strength of a photograph of the hawthorn taken in June, when it looked its best.

Disputes would follow the usual channels. A district mediation service would report that hedge cases, formerly about light and height, would now be about carbon and who cut it. Cutting a hedge would release stored carbon, debited to whoever held the shears, whoever owned the plant. “He came round with the trimmer on a Saturday,” Marguerite Fenn would say. “I told him it was mine for accounting purposes and he'd be paying to cut it. He left the trimmer on the wall and hasn't spoken since.” The birds, whose nesting season already protects a hedge for half the year, would be joined in law by the accountants.

Estate agents would list hedges by mass. Divorces would settle the hedge before the furniture. One couple in a terraced street would report staying together because neither could afford to be the one who moved to a flat with a balcony and a zero balance. In a cul-de-sac, a man would be seen at six in the morning with a laser measure, recording his neighbour's beech from the pavement, which the guidance would permit. “I've never liked him,” the neighbour would say. “But I'd like the hedge to stay, so we say good morning now.”

“The scheme rewards those who look after green infrastructure,” an official at the household budgets office would say, when asked whether it had been designed with hedges in mind. It would not, in its first phase, distinguish between a hedge grown for the budget and one grown for the birds, nor say what happens to an employee whose neighbour moves away and takes the surplus with him. The interview question would stay on the form. The candidates who answered it best would be the ones who had bought the house next door.