The short answer

Not through rent. Sam's £90,000 terrace earns about £1,500 a year after costs, interest and tax. A full upgrade at the legal maximum of £9,000 eats six years of that income.

The £10,000 headline cap does not apply to Sam. For homes worth under £100,000, the government caps required spend at 10% of value.

Tenants pay about 1.8% more rent for EPC C over D. On this house that comes to £11.70 a month. At that rate the work needs 64 years of gross rent to repay itself. The real case for spending rests on three things: compliance, a possible value uplift of up to 3.7%, and a lettable house after 1 October 2030.

What the 2030 rules actually require

The Department for Energy Security and Net Zero (DESNZ) published its response on 21 January 2026. The Warm Homes Plan landed the same day. It sets one deadline. Every privately rented home in England and Wales within the rules must reach EPC C by 1 October 2030. Ministers dropped the earlier proposal of a 2028 date for new tenancies.

  • Cost cap: £10,000 per property, or 10% of value if lower. The lower figure bites below £100,000.
  • Metrics: a fabric standard first, then the landlord picks a heating system or smart readiness standard.
  • Transition: a C on the current Energy Efficiency Rating before 1 October 2029 counts until that EPC expires.
  • Exemptions: cost cap and property value exemptions last 10 years. New landlords of tenanted homes get six months.
  • Penalty: under the new rules councils can fine up to £30,000 per property per breach.

A new "negative impacts" exemption covers measures that would harm the building. The government aims to bring the regulations into force in 2027. It will review the cap every five years after 2030.

Spending since 1 October 2025 already counts

The response lets landlords count spend on relevant measures installed since 1 October 2025. Reasonable EPC assessment costs count too. Grants and other third-party funding also count, except Boiler Upgrade Scheme money.

After a damp survey last winter, Sam paid £1,200 for loft insulation and £150 for a new EPC. Both sit inside the window, so £1,350 of the £9,000 cap has gone already. Sam's remaining exposure stands at £7,650.

Work done before October 2025 gives no credit, however much it helped the rating. Keep dated invoices for every measure from that day on.

Sam's terrace, from gross rent to net income

Our protagonist owns a two-bed terrace in a northern town, bought for £90,000 and currently rated D. Our assumptions:

  • Rent: £650 a month, £7,800 a year
  • Voids: two weeks a year, £300
  • Letting and management: 12% of rent collected, £900
  • Insurance £300, maintenance £650, safety certificates £150
  • Mortgage: £67,500 at 75% loan to value, interest-only at 5.3%
  • Tax: basic-rate individual at the 2027-28 property basic rate of 22%

Gross rent of £7,800 falls to £7,500 after voids. Operating costs take £2,000 and leave £5,500. That gives a net yield of 6.1% before finance.

Interest takes £3,578, so pre-tax cash flow lands at £1,922. Tax at 22% on £5,500 comes to £1,210. The finance cost credit, also at 22% from April 2027, returns £787. Sam pays £423 and keeps £1,499 a year. On a £22,500 deposit that means 6.7% cash-on-cash, before purchase costs.

How many years of income the upgrade eats

Three spending levels show the range for Sam:

  • £5,400, the government's estimated average spend for homes below the standard: 3.6 years of net income.
  • £7,650, the cap still open after the loft work: 5.1 years.
  • £9,000, the full cap at 10% of value: 6.0 years.

Borrowing the money changes the shape of the pain. A £9,000 further advance at 5.3% costs £477 a year in interest. After the 22% credit, the net cost reaches £372. Income drops to about £1,128, a 25% cut every year until Sam repays the loan.

Does EPC C lift rent or value?

The rent evidence looks thin. The Mortgage Works, Nationwide's buy-to-let lender, reported a 1.8% premium for C over D in May 2026. On £650 that equals £140 a year. After management and tax Sam keeps about £96. A £9,000 upgrade would need 93 years to repay through that premium.

Sale value offers more, with wide disagreement. Knight Frank found in 2022 that a D to C move added 3% above local price growth. TMW put the C price premium at 3.7% in 2026. On £90,000 those figures mean £2,700 to £3,330.

Nationwide's June 2026 study of owner-occupied homes found little difference between C and D. So the value uplift covers somewhere between nothing and 37% of a £9,000 bill.

Repair or improvement: the tax split

HMRC sorts the bill into two piles. Repairs reduce taxable rental income. Capital improvements give no income tax relief. GOV.UK tells landlords to keep records of capital costs for a future Capital Gains Tax claim.

HMRC's Property Income Manual (PIM2030) treats swapping single glazing for double glazing as a repair, because technology moved on. Where new materials bring a significant improvement, the whole cost turns capital. New insulation where none existed may fall on that side.

Keep seperate invoices for each measure. If £3,000 of Sam's bill counts as repair, it saves £660 of tax at 22%. The other £6,000 waits in the CGT base cost until sale.

Where the numbers break

Value. The cap moves with the house. At a value of £80,000, the cap drops to £8,000. The response says the benchmark value starts in 2030. It does not yet explain how landlords prove value.

Rates. Each extra point on the mortgage rate costs Sam about £527 a year after tax. At 6.3%, net income falls to £973, and £9,000 takes 9.2 years to recover.

Exemptions. If Sam spends the full cap and still misses C, the cost cap exemption lasts 10 years. That limits the downside to £9,000, plus any grant money already counted.

Timing. A C on today's rating before October 2029 holds until that certificate expires. Cheap fabric work now may buy years of compliance.

A checklist before you spend

  • Commission a fresh EPC and price each recommended measure.
  • Log every measure installed since 1 October 2025 with dated invoices.
  • Test whether a C on the current rating before October 2029 sits within reach.
  • Get a valuation if the home sits near £100,000.
  • Split invoices into repairs and improvements before you file.
  • Measure the cost against net income, never gross rent.

The verdict

On a £90,000 northern terrace, EPC C costs up to six years of net income and returns very little through rent. Treat the spend as the price of keeping a 6.1% net yield legal after 2030. Spend early, count everything since October 2025, and stop at the cap.

Where Torquity fits

Torquity estimates rent from comparable lettings with a confidence range, then works through to net yield, DSCR and cash-on-cash. Run Sam's terrace with and without a £9,000 upgrade and you see the payback in years of net income. You can also rank markets on net yield and see where compliance spend weighs least.

How we wrote this

Written with AI assistance in drafting. Rules come from the DESNZ response on privately rented homes and the Warm Homes Plan (both 21 January 2026). Tax treatment comes from HMRC manual PIM2030 (updated 21 May 2026) and GOV.UK rental income guidance (updated 19 March 2025). Tax rates come from Finance Act 2026, section 7. Mortgage rates come from Moneyfacts (26 March 2026). Premium figures come from TMW via Mortgage Solutions (5 May 2026), Knight Frank (October 2022) and Nationwide (June 2026). The worked example uses Torquity's assumptions and does not constitute legal, tax or financial advice.