Government has proposed an EPC C minimum for the private rented sector in England and Wales from 1 October 2030. It is not law yet: it needs primary legislation and then a statutory instrument amending the 2015 Regulations, and neither has happened. The minimum you must let at today is band E. Most landlords planning for C have not started, and many assume they have time. Some are right, though fewer than they think.
The issue is not the date. It is the end-to-end timeline of actually getting a property from its current rating to EPC C. Assessment, grant applications, contractor queues, works, re-assessment: each step takes time, and they stack. Start late and 2030 arrives before you are done.
This guide walks through the full retrofit process, using a real worked example, so you can plan accordingly.
The Full Process: Seven Steps
Getting a rental property to EPC C involves seven distinct stages:
- Initial EPC assessment, establish your current rating and recommended measures
- Planning and prioritisation, decide which measures to install, in which order
- Grant applications, apply for Boiler Upgrade Scheme, ECO4, or other funding
- Contractor quotes, get three quotes, check TrustMark accreditation
- Works, installation of measures
- Re-assessment, new EPC issued by accredited assessor
- New certificate lodged, the EPC register is updated and the rating is demonstrable
On paper this is straightforward. In practice, each step has a queue.
Worked Example: The Willows, Coventry
Mark owns three buy-to-let properties in the Midlands. The Willows is his problem child: a three-bedroom 1930s semi-detached in Coventry, currently tenanted, rated D (58). It is legal to let today, but to meet the proposed 2030 standard it would need to reach at least C (69+).
Mark starts his retrofit journey in January 2026. Here is what his timeline actually looks like.
Month 1: Initial EPC Assessment
Mark books an accredited domestic energy assessor through the TrustMark register. There is a two-week wait, which is typical for Coventry in January. The assessment takes 90 minutes. Cost: £80.
The assessor's report comes back:
- Current score: D (58)
- Recommended measures:
- Loft insulation top-up (currently 50mm, should be 270mm)
- Cavity wall insulation (the property has unfilled cavity walls)
- Replace the 20-year-old gas boiler with either an A-rated condensing boiler or an air source heat pump
The report also shows that with all three measures installed, the property's projected score would be C (72). Mark now knows exactly where he stands.
Month 2: Grants and Applications
Mark does not want to spend more than he has to. He investigates two funding routes.
Boiler Upgrade Scheme (BUS): The Boiler Upgrade Scheme offers £7,500 toward an air source heat pump for properties in England and Wales. Mark applies through an accredited MCS installer. The application is submitted in early February. The installer warns him that BUS vouchers are currently being processed in three to four weeks.
ECO4: The cavity wall insulation and loft insulation top-up may be fully funded through ECO4, provided Mark's tenant is on qualifying benefits. Mark's tenant receives Universal Credit, which qualifies. He contacts a local ECO4 installer (via the Energy Saving Trust's referral service) and gets added to their schedule. The ECO4 installer estimates works in six to eight weeks due to current demand.
Month 3: Contractor Quotes
With grants in motion, Mark gets three quotes for the heat pump installation from MCS-accredited contractors:
- Contractor A: £10,200 installed, including all ancillary pipework and a smart thermostat
- Contractor B: £9,800 installed
- Contractor C: £11,500 installed (larger heat emitters, higher efficiency spec)
Mark goes with Contractor B at £9,800. After the £7,500 BUS grant, his out-of-pocket cost is £2,300.
The ECO4 cavity wall insulation comes in at £800 fully funded (no cost to Mark). The loft insulation top-up is quoted at £400 by the ECO4 installer, also fully funded for qualifying properties.
Mark's revised total landlord cost at this point: approximately £2,300 (just the heat pump top-up after grant).
Month 4: Works
The ECO4 works are scheduled first. Cavity wall insulation takes one day. Loft insulation takes half a day. Both are done in the first week of Month 4 with minimal disruption to the tenant.
The heat pump installation follows two weeks later. It takes three days: first day for groundwork and outdoor unit installation, second day for indoor unit and pipework, third day for commissioning and testing. The tenant needs to be present on the final day for the handover.
Total disruption to the tenant: approximately four days across two weeks.
Month 5: Re-Assessment and New Certificate
Works complete. Mark books a re-assessment through the same accredited assessor. There is a one-week wait. The assessment takes 90 minutes.
New score: C (72). Certificate issued and lodged on the EPC register.
Mark's property is now compliant with the proposed 2030 standard. Total elapsed time from first assessment booking to new certificate: five months. Total landlord cost (after grants): approximately £3,300 (£2,300 heat pump net cost + £80 initial assessment + £80 re-assessment + small contingency for thermostat wiring).
What Can Slow You Down
Mark's timeline ran smoothly. That is not always the case. The main sources of delay:
ECO4 waiting lists. In some areas, ECO4 installers are booking six months or more ahead. If your tenant qualifies, apply as soon as possible. Waiting until after you have the assessment report is fine, but do not delay after that.
BUS voucher processing. The Boiler Upgrade Scheme has experienced periodic backlogs. Vouchers are valid for three months from issue (extendable once). If your MCS installer is slow to submit the application, the voucher may expire before works are done.
Planning permission. Properties in conservation areas, listed buildings, or certain flat conversions may require planning permission for external wall insulation or heat pump outdoor units. This can add two to four months. Know your property's status before you start.
Contractor availability. MCS-accredited heat pump installers are in short supply in some regions. In rural areas and Scotland, booking times of four to six months are not unusual. This is expected to worsen as 2030 approaches. See our article on the EPC assessor and installer shortage.
Property fabric surprises. Old properties sometimes reveal unexpected issues once works begin: unfilled party wall cavities, non-standard construction, asbestos in older insulation. Each surprise adds cost and time.
What Can Speed You Up
Start with quick wins. Loft insulation, draught-proofing, and LED lighting are cheap, fast, and can shift a property's rating by several points. If you are sitting at D (60) and these measures push you to C (70), you may not need the heat pump at all. Get the assessment first and understand the full picture.
Get the assessment done now. You cannot apply for grants, get accurate quotes, or make decisions without an up-to-date EPC assessment. Booking the assessment is the one action that unlocks everything else. It costs £60 to £120 and takes a morning.
Apply for grants before deciding on contractors. BUS vouchers are granted in advance of works. ECO4 works are scheduled through installers. Both take time. Start the paperwork before you commit to a contractor or a timeline.
Use a retrofit coordinator. For landlords with multiple properties or complex properties, a TrustMark-registered retrofit coordinator can manage the whole process: assessment, grant applications, contractor sequencing, sign-off. Their fee is often offset by better grant outcomes and fewer mistakes.
The Bottom Line
If you start in 2026, you have time. A typical retrofit, even a complex one, can be completed in five to eight months if grants are secured and contractors are available. You have room to get it right.
If you start in 2028, the maths changes. Contractor queues will be longer. Assessors will be booked out. Grant funding may be depleted. A five-month process may become a twelve-month one, which puts you close to October 2030 with no margin if the standard does become law.
The Boiler Upgrade Scheme is still open and funded. ECO4 closes at the end of December 2026 with no confirmed replacement. The window for free insulation works is closing faster than the proposed compliance date.
Mark started in January 2026 and had his C-rated certificate in May. His total out-of-pocket cost was £3,300, largely absorbed by a grant that may not exist in two years.
That is the opportunity sitting in front of every landlord with a sub-C property right now.