Green Party rent cap could cost landlords £2,186 per property

A landlord charging England’s average rent could receive £2,186 less over three years under the Green Party’s proposed cap, if annual increases were restricted to 2% instead of continuing at 4%.

However, Property118’s analysis shows that the gap could reach £4,315 per property if rents were frozen for all three years, compared with annual increases of 4%.

Our illustrative calculation uses the latest Office for National Statistics figures to examine the potential impact of Green Party leader Zack Polanski’s proposed three-year restriction.

It is not a forecast of the average landlord’s loss. The outcome would depend on future rent growth, when increases took effect and the policy’s detailed rules, which have yet to be set out.

The ONS puts England’s average monthly private rent at £1,459 in August, with annual growth of 4%.

Those figures provide a starting point for the calculation, rather than evidence that every landlord could achieve that increase.

How the Green rent cap would work

In his conference speech on 2 October, Mr Polanski proposed limiting private rent increases to whichever was lowest out of CPI inflation, wage growth or 2%.

The restriction would last three years, followed by a longer-term Fair Rents Guarantee.

For landlords, the important detail is that 2% would be the maximum permitted increase. If inflation or wage growth fell below that level, the restriction would tighten further.

Taking the £1,459 average monthly rent, a 2% increase would add £29.18 a month.

A 4% rise would add £58.36, leaving a difference of £350.16 over the first full year.

That gap grows as subsequent increases build on different starting rents.

The three-year cost to landlords

The following illustration assumes an increase at the beginning of each year, including year one, continuous occupation and no arrears. It also assumes inflation and wage growth remain at or above 2%, allowing the full proposed ceiling.

The comparison carries forward England’s latest 4% annual growth rate as a hypothetical alternative, not an ONS forecast.

Illustrative calculations retain full precision before rounding. Rounding each monthly payment first would slightly alter the totals.

By the third year, the landlord would receive about £93 less each month than under the 4% comparison.

Across five properties with identical starting rents and review dates, the cumulative difference would reach approximately £10,930.

However, neither figure represents a reduction from the rent being collected today. It measures rent income missed out on against the assumed alternative.

A landlord who would otherwise have left the rent unchanged would not suffer that calculated loss.

Could the restriction cost more?

However, a lower ceiling would widen the difference.

If inflation were 1% and wage growth 4%, the permitted increase would be 1%.

Applied at all three annual reviews, that would leave the landlord approximately £3,258 behind the same 4% comparison.

If one of the measures were zero and the rule froze increases throughout the period, the gap would reach about £4,315.

These are scenarios, not predictions. The speech also leaves unanswered what would happen if inflation or earnings growth turned negative: a compulsory rent reduction cannot be assumed.

The choice of earnings measure, reference months and treatment of revised figures would need to be specified before landlords could calculate an actual permitted increase.

The average rent is not an average loss

Using the UK-wide figures produces a different result.

The ONS reports a provisional average monthly rent of £1,400 and annual growth of 3.8%. Comparing three annual increases at that rate with three increases of 2% produces approximately £1,885 in gross rent income missed out on.

That is a statistical benchmark, not evidence that the policy would apply uniformly across the UK.

For landlords, the commercial concern is how restricted income growth would affect insurance, service charges, repairs and mortgage payments.

Those bills would not automatically be constrained by the same ceiling.

A property with a modest surplus could therefore experience a proportionately larger squeeze on the cash remaining after expenses. An unencumbered property with lower running costs would be in a different position.

The speech does not explain whether substantial improvements or exceptional expenses could justify a higher increase. Nor does it establish whether the restriction would cover existing tenancies, new lets or both.

In the England illustration, the tenant would pay the same £2,186 less over three years, assuming everything else remained unchanged.

Until more details emerge, the potential £2,186 cost is an illustration of the three-year income difference for a property charging England’s average rent.