King Charles and Prince William could reportedly face a bill of around £10 million to improve the energy efficiency of rental properties across their estates. That is a hefty bill, even by royal standards, but the Government expects ordinary landlords across England and Wales to find nearly £9.9 billion.
The Guardian has reported that King Charles and Prince William could be required to spend up to £10 million upgrading rental properties held across the Duchy of Lancaster, the Duchy of Cornwall and the Sandringham estate.
£10 million is an eye-catching number. It also makes the proposed new EPC rules easier for people outside the private rented sector to understand.
However, the King and the Prince of Wales are unlikely to be worrying about whether the next boiler replacement will empty their reserve account. Nor are they likely to be speaking to a mortgage broker because spending £10,000 on a cottage would wipe out several years of rental profit.
Thousands of ordinary landlords could soon be doing exactly that.
How did the Guardian arrive at £10 million?
The Guardian examined more than 700 domestic EPCs connected with the three royal estates. Of those, 630 were rated D or below and would not meet the Government’s proposed higher standard.
The total number of domestic properties held across the estates is believed to exceed 1,200. If the EPC sample reflects the wider portfolio, more than 1,000 properties could need work.
Multiply 1,000 properties by the proposed £10,000 maximum expenditure per property and you arrive at the £10 million headline.
That does not mean a £10 million invoice has already been pushed through the gates of Buckingham Palace. Some properties may be outside the regulations, some may qualify for exemptions, some may already have improvements planned and many will cost less than £10,000 to bring up to standard.
Nevertheless, the figure gives us a useful indication of what happens when a per-property cost cap is applied across a large portfolio.
It also raises a much bigger question.
If the royal estates could face a bill of £10 million, where does the Government think the rest of the private rented sector will find £9.87 billion?
The Government’s own figure is £9.87 billion
This is not a figure produced by a landlord pressure group. It comes directly from the Government’s own impact assessment.
Under its preferred policy, the Government estimates that by 2030:
- 1,753,974 private rented properties will be upgraded;
- landlords will spend £9.87 billion;
- the average cost will be £5,387 per upgraded property;
- tenants will save an average of £210 a year on energy bills; and
- 415,020 households will be lifted out of fuel poverty.
There are obvious benefits in making homes warmer and cheaper to heat. Nobody should be defending cold, damp or badly maintained rental properties, whether they belong to a landlord with one house or a royal estate with more than 1,000.
However, warm words about social benefits do not pay builders, heating engineers or insulation installers.
The landlord is expected to spend an average of £5,387 today. The tenant is expected to save an average of £210 a year.
On that basis, the simple cost-to-energy-saving period is nearly 26 years, before allowing for borrowing costs, the time value of money or the risk that the work costs more than the Government’s model assumes.
Of course, that is not a complete investment appraisal. Some work may increase the value of the property, reduce future maintenance costs or improve its appeal to tenants.
Even so, it exposes the basic problem. The landlord funds the work, while most of the direct financial benefit goes to the tenant through lower energy bills.
That may be good social policy, but it is not automatically a viable investment for the landlord.
A £10,000 property cap is not a £10,000 landlord cap
The Government originally consulted on a maximum spend of £15,000 per property. Following widespread concern, it reduced that figure to £10,000.
That was better, but the phrase “£10,000 cost cap” is misleading when it is repeated without the words per property.
| Properties requiring work | Government’s average cost | Maximum at £10,000 per property |
|---|---|---|
| 1 | £5,387 | £10,000 |
| 4 | £21,548 | £40,000 |
| 10 | £53,870 | £100,000 |
| 20 | £107,740 | £200,000 |
The same impact assessment says that 83% of landlords own between one and four properties, including 45% who own just one.
It then says there should not be a greater burden on smaller landlords because the cost increases in proportion to the number of substandard properties they own.
That is arithmetic, not economics.
A landlord with one rental property, one mortgage and no spare cash does not suddenly become able to fund a £10,000 upgrade because a royal estate has a bigger total bill.
Financial capacity does not increase or decrease neatly with the number of properties owned. It depends on cash flow, borrowing, equity, mortgage terms, other liabilities and how much of the landlord’s income has already been swallowed up by tax, interest and repairs.
For a landlord with two or three mortgaged properties, a £20,000 or £30,000 programme of works could determine whether the business remains viable.
There is no magic pot of money
A £9.87 billion bill can only be funded from existing cash, new borrowing, higher rents, reduced spending elsewhere or property sales. There is no magic sixth option called “the landlord absorbs it”.
Some landlords will use savings. Some will refinance. Some will postpone other investment. Some will increase rents where the market allows them to do so. Others will sell properties where the cost of compliance destroys the return on the capital tied up in them.
The Government’s impact assessment quietly acknowledges this.
It says that possible rent increases have not been included in the monetised benefits to tenants. It also recognises that some tenants could incur moving costs if their landlord sells, and that the policy is likely to make private letting less attractive and increase barriers to entry.
Those are not minor footnotes. They go to the heart of whether the policy will work as intended.
A tenant may save £210 a year on energy bills, but that benefit could be wiped out by a relatively small rent increase. A tenant gains nothing from a more efficient rental property if the landlord sells it to an owner-occupier and there is one less home available to rent.
That does not mean every landlord will increase the rent or sell. It means Ministers need to stop pretending that nearly £10 billion can be taken out of landlord businesses without changing commercial decisions.
Older properties cannot be treated like modern boxes
The royal estates are a particularly useful example because many of their homes are older cottages, farmhouses and rural properties.
These are often the most difficult and expensive buildings to improve. They may have solid walls, listed features, limited access, unusual heating systems or construction methods that do not respond well to modern retrofit measures.
The Government’s impact assessment estimates that 81% of properties in its rural category will require upgrades by 2030. It puts the average landlord expenditure for those properties at £6,162, compared with £4,427 for city-centre homes.
An EPC recommendation is not a building survey. Nor does a computer-generated score guarantee that a recommended measure is suitable for the fabric of a particular building.
The Government has effectively admitted as much by announcing a specific exemption for solid-wall insulation. Its consultation response acknowledges that badly installed solid-wall insulation can create condensation, damp and mould.
That alone should put an end to the idea that every D-rated property can be pushed through the same standard list of improvements.
Bad retrofit can damage a building, cost a fortune to put right and leave the tenant worse off than before.
The current rules and the 2030 proposals are not the same
The Guardian has also reported that more than 100 homes connected with the royal estates had EPC ratings of F or G.
That raises a separate issue because the current minimum standard for relevant private rented homes is EPC E, unless a valid exemption applies.
The estates have responded by saying that not every property is within the scope of the regulations, that exemptions apply in some cases and that the properties to which the regulations apply are compliant.
Those current compliance questions should not be blurred with the estimated cost of meeting the proposed 2030 standard.
A D-rated property is not currently unlawful simply because it may fail a future standard. Equally, an in-scope F or G-rated property requires action now or a valid exemption. The two issues need to be reported separately.
Landlords are being asked to plan before the new system is ready
The Government says all tenancies within the scope of the new regulations must meet the higher standard by 1 October 2030.
The maximum required expenditure will be £10,000 per property over ten years. Where the property still fails after the relevant expenditure has been incurred, the landlord should be able to register an exemption.
The Government also wants the maximum fine increased to £30,000 per property, per breach, although it still needs new primary legislation to obtain some of those enforcement powers.
The difficulty is that the new EPC system on which the rules will be based is not yet operating.
Following industry discussions, the Government announced in March 2026 that the launch of reformed domestic EPCs had been delayed until the second half of 2027.
That leaves landlords with roughly three years between the new assessment system becoming available and the October 2030 deadline.
Properties achieving an existing EPC C before 1 October 2029 are expected to be treated as compliant until that EPC expires or is replaced. Qualifying expenditure incurred since 1 October 2025 should also count towards the future cost cap.
However, landlords who spend money now cannot yet know exactly how their properties will score against the new fabric, heating-system and smart-readiness metrics.
The direction of travel is clear, but the final measuring equipment is still being assembled.
What should landlords do now?
Panic-spending £10,000 on every D-rated property would make no sense. Doing nothing until 2029 would be equally dangerous.
The starting point should be a commercial review of the whole portfolio.
- Which properties already meet EPC C?
- Which could reach the standard through sensible work that was due to be carried out anyway?
- Which are older or solid-wall buildings that need specialist assessment?
- How would the work be funded and what would it do to cash flow and borrowing?
- Would the expenditure improve the property’s value or rental return?
- Would the capital produce a better return if a weaker property were sold and the money reinvested elsewhere?
Landlords should also retain invoices, reports, photographs and evidence of relevant expenditure incurred since 1 October 2025. That paperwork may become important when demonstrating compliance or applying for an exemption.
Most importantly, the decision should not be reduced to whether a property can technically be pushed over an EPC line.
A property may be capable of reaching the required score but no longer make commercial sense once the cost of the work, financing, tax, maintenance and existing return on equity are considered together.
For one property, the right decision may be to improve it. For another, it may be to refinance and complete the work alongside a wider refurbishment. For a poorly performing property with a large amount of trapped equity, selling may be the more sensible option.
That is not avoiding responsibility. It is how any properly run business responds to a major new capital requirement.
The royal bill is the headline. The £9.87 billion landlord bill is the real story
The King and the Prince of Wales may well spend millions improving their rental properties. Given the conditions alleged in some of the reporting, tenants will expect the royal estates to lead by example.
However, their ability to fund the work tells us very little about whether an ordinary landlord can do the same.
The Government expects nearly £9.9 billion to be invested by landlords by 2030. Some of that money will come from savings, some from refinancing, some from higher rents and some from selling rental properties.
Ministers may not like every one of those outcomes, but they cannot impose the cost and then deny the commercial consequences.
The King can probably find £10 million without selling Sandringham.
Many ordinary landlords will not be able to find £10,000 without selling the rental property.
Do you know what the proposed EPC rules could cost across your portfolio, and would every property still be worth keeping? Please share your thoughts in the comments below.
