TL;DR:
- RdSAP 10 is now the standard for residential EPC assessments in England and Wales, requiring detailed measurements to improve accuracy and reflect modern technologies. Landlords must act now by updating EPCs, prioritizing fabric improvements, and managing costs within a £10,000 cap to meet the 2030 EPC C requirement. Early compliance with EPC C before October 2029 offers significant grandfathering benefits and simplifies future obligations.
RdSAP 10 launched on 15 June 2025, replacing the previous assessment methodology with a more detailed approach that requires assessors to measure every window, record granular room-in-roof data, and capture ventilation and renewable technology inputs. If you let residential property in England or Wales, you need to act now: order an updated EPC under RdSAP 10 and review the fabric improvement recommendations on the report.
Quick summary:
- 15 June 2025: RdSAP 10 takes effect; all new EPCs use the updated methodology
- 1 October 2025: Spend on improvements from this date counts towards the £10,000 cost cap
- 1 October 2029: Grandparenting cut-off; achieve EPC band C by this date and your property is treated as compliant with the 2030 standard until the EPC expires
- 1 October 2030: All private rented sector (PRS) properties in England and Wales must meet the new EPC C standard
- Cost cap: £10,000 per property; exemptions last 10 years
The current MEES floor remains EPC band E. Properties rated F or G cannot be let without a valid exemption, and that rule has applied to all continuing lets since 1 April 2020. The 2025 changes layer a more rigorous assessment methodology on top of that baseline and set the trajectory towards a much higher standard by 2030.
Table of Contents
- What are the new EPC regulations 2025 and what is RdSAP 10?
- Which properties and landlords are affected, and when?
- How will RdSAP 10 affect your costs and day-to-day management?
- What exemptions are available and how does enforcement work?
- What should landlords do right now?
- What will your EPC assessment look like under RdSAP 10?
- Your 7-step compliance roadmap with timeline and cost guidance
- Key takeaways
- The view from the ground: what assessors and agents are actually seeing
- How Completeepc helps landlords comply with the 2025 changes
- Useful sources for landlords
- FAQ
What are the new EPC regulations 2025 and what is RdSAP 10?
RdSAP 10 is the updated Reduced Data Standard Assessment Procedure, the calculation engine that sits behind every domestic EPC in England and Wales. The government updated it to improve accuracy, account for technologies that did not exist when the previous version was written, and produce data that better reflects real-world energy use.
The technical changes are significant. Under the old methodology, assessors used simplified look-up tables for windows and glazing. RdSAP 10 requires individual measurement of every window opening, including frame type, glazing specification, and orientation. Room-in-roof spaces now require detailed recording of insulation position and thickness. Ventilation options have been expanded to cover mechanical ventilation with heat recovery (MVHR) and other modern systems. Renewable technologies, including solar PV, solar thermal, and heat pumps, are modelled with greater precision. Where an air pressure test result is available for a property, assessors can now include it, which can meaningfully improve or worsen a score depending on the building’s actual airtightness.
| Feature | Previous RdSAP | RdSAP 10 |
|---|---|---|
| Window inputs | Simplified glazing type | Individual measurement per window, frame and orientation |
| Room-in-roof | Basic insulation flag | Detailed insulation position and thickness |
| Ventilation | Limited options | MVHR and additional modern systems included |
| Renewables | Basic PV/solar thermal | More precise modelling of heat pumps and renewables |
| Airtightness | Not included | Air pressure test results can be recorded |
| Heating system | Broad system types | Refined modelling of controls and heat emitters |
The practical effect is that two properties that scored identically under the old methodology may score differently under RdSAP 10. Flats and mid-terrace properties, which previously had their thermal bridging and shared-wall heat loss approximated, tend to benefit from the more accurate treatment. Detached properties with older single-glazed windows may see scores fall slightly as individual window performance is now captured more precisely.
Pro Tip: If your property already has a valid EPC, you are not required to commission a new one immediately. However, if you are planning improvement works, ordering a fresh RdSAP 10 assessment first gives you a more accurate baseline and ensures your recommended measures reflect the updated methodology.
Which properties and landlords are affected, and when?
The EPC compliance changes 2025 apply to residential properties in England and Wales. Scotland and Northern Ireland operate separate regulatory frameworks with their own timelines and standards; landlords with properties in those jurisdictions should check the relevant devolved guidance.
For England and Wales, the key dates are:
- 15 June 2025: RdSAP 10 becomes the mandatory methodology for all new domestic EPC assessments
- 1 October 2025: Improvement costs incurred from this date count towards the £10,000 cost cap
- Second half of 2026: New-style EPCs based on the Home Energy Model (HEM) are anticipated; old-style EPCs will be accepted during transition
- 1 October 2029: Grandparenting cut-off; properties achieving EPC C before this date are treated as compliant with the 2030 standard until the EPC expires
- 1 October 2030: Single compliance deadline for all PRS properties to meet the new EPC C standard
The government has deliberately chosen a single compliance date rather than a tenancy-trigger approach, which means there is no mechanism to delay compliance by avoiding new tenancies. Every landlord with a property below EPC C in England and Wales needs a plan.
Important: The government’s January 2026 response confirmed a dual-metric standard for 2030: a primary fabric performance metric plus a secondary standard covering smart readiness or heating system quality. Landlords who act now on fabric improvements are already working towards both metrics.
Letting agents have their own obligations. Agents marketing a property for rent must be able to provide a valid EPC to prospective tenants. Under RdSAP 10, the EPC content will look different, with more detailed fabric data and potentially different recommended measures, so agents should brief landlords on what to expect when EPCs are renewed.
How will RdSAP 10 affect your costs and day-to-day management?
The most immediate financial impact is on assessment fees. RdSAP 10 requires assessors to collect significantly more on-site data, which extends site visit times. Measuring every window individually in a large Victorian terrace takes considerably longer than applying a simplified glazing type from a look-up table. Assessment fees may rise modestly compared to pre-2025 rates, though the exact amount varies by assessor and property size.
Beyond the assessment itself, the more granular data inputs mean that recommended improvement measures on the EPC may shift. A property that previously showed loft insulation as the top recommendation might now show secondary glazing or draught-proofing as higher priorities, depending on how the individual window measurements affect the score. This matters for retrofit planning: the new recommendations are more accurate, so they are worth taking seriously when deciding where to spend first.
Typical cost ranges to budget for:
- EPC assessment (RdSAP 10): Fees vary by assessor and property; expect slightly higher rates than pre-2025 due to extended data collection
- Draught-proofing and basic fabric works: Generally low cost and often the most cost-effective first step
- Loft insulation (where absent): One of the most cost-effective measures for properties with accessible loft space
- Cavity wall insulation: Costs vary significantly by property type and wall condition
- Solid wall insulation (internal or external): The most expensive fabric measure; often the reason a property cannot reach band C without hitting the cost cap
For retrofit planning, the principle is fabric first: address the building envelope before upgrading heating systems. This approach aligns with the government’s dual-metric standard, where fabric performance is the primary metric. Properties that invest in insulation and draught-proofing now will be better positioned for both the 2029 grandparenting deadline and the 2030 compliance date.
Operationally, landlords should factor in longer lead times for assessments and contractor availability. Getting quotes and scheduling works during quieter periods reduces both cost and disruption to tenants.
What exemptions are available and how does enforcement work?
The £10,000 cost cap and 10-year exemption validity are designed to protect landlords from disproportionate upfront costs while still driving necessary upgrades. Costs of EPCs and reasonable assessment fees count towards the cap, and improvements made since 1 October 2025 can be included.
| Exemption type | Typical evidence required | Validity |
|---|---|---|
| High cost / cost cap | Quotes from at least three contractors; receipts for completed works; EPC costs | 10 years |
| Wall insulation | Technical report confirming wall type is unsuitable; assessor confirmation | 10 years |
| Third-party consent | Evidence of application and refusal (freeholder, planning authority, lender) | 5 years |
| Devaluation | Independent surveyor’s report confirming improvement would reduce market value | 5 years |
| All reasonable improvements made | Evidence that all cost-effective measures have been installed up to the cap | 10 years |
To register a cost-cap exemption, you must demonstrate that you installed all cost-effective measures up to the point where the next improvement would push the total above £10,000. Keeping a clear record of every quote and receipt is not optional; it is the evidence base for your exemption application.
Enforcement is handled by local authorities, who have the power to issue compliance notices and financial penalties. The government has signalled its intention to seek primary legislation to strengthen enforcement further, including higher maximum civil penalties. Properties below the required standard without a valid exemption registered on the PRS Exemptions Register are at risk of penalty action.
Pro Tip: Register exemptions on the PRS Exemptions Register as soon as the qualifying condition is met. Do not wait until a compliance check triggers a notice. An exemption registered proactively is far easier to defend than one submitted under pressure.
What should landlords do right now?
The most valuable thing you can do today is order a new EPC under RdSAP 10 if your current certificate is approaching expiry or if you are planning works. The updated methodology gives you a more accurate picture of your property’s actual performance and a more reliable set of recommended measures to work from.
- Order or renew your EPC. Commission a new RdSAP 10 assessment. Review the recommended fabric measures carefully; they will be more specific than those on older EPCs.
- Prioritise fabric improvements. Start with the measures the EPC recommends as highest priority. Get at least two contractor quotes for each measure and keep copies.
- Check grant eligibility. The Boiler Upgrade Scheme and the Great British Insulation Scheme may reduce your out-of-pocket costs. Eligibility criteria apply.
- Identify third-party consent constraints. If your property is leasehold, listed, or in a conservation area, identify consent requirements early. Delays in obtaining consent can affect your timeline significantly.
- Document all spend from 1 October 2025. Every invoice, receipt, and EPC cost from this date counts towards the £10,000 cap. Set up a simple folder, physical or digital, for each property.
- Assess exemption eligibility. If a property genuinely cannot reach EPC C within the cost cap, begin gathering the evidence needed for the appropriate exemption type.
- Target EPC C before 1 October 2029. Achieving band C before the grandparenting cut-off means your property is treated as compliant with the 2030 standard until the EPC expires, potentially delaying the need for more complex dual-metric works.
Pro Tip: If you have a portfolio of properties, triage them by current EPC rating and likely improvement cost. Properties already at D are often one or two measures away from C; tackle those first to bank grandparenting compliance before 2029.
What will your EPC assessment look like under RdSAP 10?
Assessors working under RdSAP 10 will spend more time on site than you may be used to. The additional data collection requirements mean a thorough inspection of a medium-sized property can take noticeably longer than under the previous methodology.
What assessors will measure and record:
- Every window opening: dimensions, frame material, glazing specification, and orientation
- Room-in-roof spaces: insulation position (between rafters, at ceiling level, or both) and thickness
- Ventilation systems: type, location, and any mechanical ventilation with heat recovery
- Renewable technologies: solar PV panel area and orientation, solar thermal collectors, heat pump details
- Airtightness: if a pressure test result is available, the assessor can record it
- Heating system controls: programmer, room thermostat, thermostatic radiator valves, and smart controls
To help your assessor work efficiently and avoid a return visit, prepare the following before they arrive:
- Floor plans or building drawings if available
- Invoices or certificates for any insulation, glazing, or heating work completed in the last ten years
- Boiler installation certificate and controls documentation
- Any airtightness or pressure test results
- Evidence of third-party consent constraints (leasehold documents, listed building consent)
It is also worth asking your assessor directly: which inputs will have the greatest effect on the score? Are there any measures I should complete before the assessment to capture the improvement? What is the likely time and cost for this inspection? A good assessor will answer these questions clearly, and the answers will help you plan works in the right order.
Pro Tip: Providing invoices for recent insulation or boiler works in advance is one of the most effective ways to keep assessment fees down. If the assessor can confirm a measure from documentation rather than inference, it reduces both time on site and the risk of a conservative assumption being applied.
Your 7-step compliance roadmap with timeline and cost guidance
| Step | Action | Suggested timing | Cost notes |
|---|---|---|---|
| 1 | Commission RdSAP 10 EPC | Now | EPC cost counts towards the £10,000 cap |
| 2 | Review fabric recommendations | Immediately after EPC | No cost; informs all subsequent decisions |
| 3 | Obtain contractor quotes (min. two per measure) | Within 4 weeks of EPC | Keep all quotes as exemption evidence |
| 4 | Plan and schedule improvement works | Before 1 October 2025 spend cut-off if possible | Costs from 1 October 2025 count towards cap |
| 5 | Apply for grant funding | Before committing to works | Boiler Upgrade Scheme, Great British Insulation Scheme |
| 6 | Commission post-retrofit EPC | After works complete | EPC cost counts towards the £10,000 cap |
| 7 | Register exemption if required | As soon as qualifying condition is met | No fee; evidence folder required |
The strategic priority is Step 6: achieving EPC C on a post-retrofit assessment before 1 October 2029 triggers grandparenting. A property that reaches C before that date is treated as compliant with the 2030 dual-metric standard until the EPC expires. Given that EPCs are valid for ten years, a property assessed in 2028 and rated C would be covered until 2038, well beyond the 2030 compliance deadline.
Note that if your property requires significant structural works as part of a retrofit, you may need to factor in the building regulations approval process for certain installations. Internal wall insulation and some ventilation systems require building control sign-off, and that approval timeline should be built into your project schedule.
The government has confirmed that new-style EPCs based on the Home Energy Model are anticipated in the second half of 2026. Old-style EPCs will be accepted during the transition period, so an RdSAP 10 EPC obtained now remains valid and useful.
Key takeaways
RdSAP 10 is now live, the £10,000 cost cap protects landlords from extreme retrofit costs, and achieving EPC C before 1 October 2029 is the single most valuable compliance step available today.
| Point | Details |
|---|---|
| RdSAP 10 is live | All new domestic EPCs in England and Wales use the updated methodology from 15 June 2025. |
| £10,000 cost cap applies | Spend from 1 October 2025 counts; EPC costs are included; exemptions last 10 years. |
| Grandparenting is a real advantage | Achieve EPC C before 1 October 2029 and your property is treated as compliant until the EPC expires. |
| Dual-metric standard from 2030 | The 2030 standard requires a fabric performance metric plus a secondary heating or smart readiness standard. |
| Completeepc can help | Book a qualified RdSAP 10 domestic EPC assessment through Completeepc to get an accurate baseline and compliant documentation. |
The view from the ground: what assessors and agents are actually seeing
The most common surprise assessors report under RdSAP 10 is how much individual window measurements shift the score for older properties. A Victorian terrace with a mix of original sash windows and later double-glazed replacements now gets each opening assessed individually, rather than having a blended glazing type applied to the whole property. For some landlords, this produces a lower score than expected. For others, particularly those who have replaced windows piecemeal over the years, it produces a better one. The lesson is straightforward: do not assume your existing EPC score will carry over. Get a fresh assessment.
From an agent’s perspective, the change that matters most is the shift in recommended measures. Landlords who have been planning works based on an older EPC may find the priority order has changed. One pattern worth noting: a property that previously showed cavity wall insulation as the top recommendation might now show secondary glazing or draught-proofing higher up the list, because the individual window data has revealed a greater heat loss pathway than the old methodology captured. Agents who brief landlords on this early avoid the frustration of works being planned and costed around recommendations that no longer reflect the property’s actual profile.
The grandparenting provision is genuinely useful, and landlords who move early will benefit from it. A landlord who commissions an RdSAP 10 assessment now, installs the recommended fabric measures, and achieves band C on a post-retrofit EPC before October 2029 will not need to revisit compliance until that EPC expires, potentially in the late 2030s. That is a meaningful reward for acting ahead of the deadline rather than waiting.
How Completeepc helps landlords comply with the 2025 changes
Landlords in London who need a compliant RdSAP 10 domestic EPC, a post-retrofit assessment, or guidance on which measures to prioritise will find Completeepc a practical first call. The service is built around qualified Domestic Energy Assessors who understand the additional data requirements of RdSAP 10 and can advise on the evidence you should prepare before the visit.
Completeepc also handles commercial EPC assessments for landlords with mixed portfolios, so you can manage compliance across property types with a single provider. Pricing is competitive, turnaround is fast, and the assessors are accredited and experienced with the updated methodology.
To book an assessment or ask about compliance documentation, visit completeepc.co.uk or use the contact form to get a quote for your property.
Useful sources for landlords
The sources below are the primary references for the rules covered in this guide. Bookmark them and check back as secondary legislation and the Home Energy Model methodology are confirmed.
- Improving the energy performance of privately rented homes: 2025 update (GOV.UK) — the consultation and government response, including the dual-metric standard and cost cap decisions
- Government response: improving the energy performance of privately rented homes (PDF) — the full legislative response document
- Impact assessment: improving the energy performance of privately rented homes (GOV.UK) — detailed analysis of timelines, HEM introduction, and compliance costs
- Domestic private rented property: minimum energy efficiency standard — landlord guidance (GOV.UK) — current MEES rules, exemption types, and the PRS Exemptions Register
- Find an energy certificate (GOV.UK) — check the current EPC for any property in England, Wales, or Northern Ireland
- Boiler Upgrade Scheme (GOV.UK) — grant support for heat pump and biomass boiler installations
- Great British Insulation Scheme (GOV.UK) — funding for insulation improvements, subject to eligibility
To verify that a Domestic Energy Assessor is accredited, check the assessor’s accreditation scheme directly. Accreditation schemes approved by the government include Elmhurst Energy, Stroma Certification, and ECMK, among others. An accredited assessor will be able to provide their scheme membership number on request.
“The legislative changes set out in this document will be subject to Parliamentary approval. The consultation on ‘Improving the energy performance of private rented homes’ was published on 7 February 2025 and closed on 2 May 2025.” — Government response to the 2025 consultation
This article provides general information about EPC regulations and compliance. It is not legal or professional advice. Confirm current rules and your specific obligations with GOV.UK guidance or a qualified professional.
FAQ
What changed in EPC assessments from June 2026?
RdSAP 10 replaced the previous methodology on 15 June 2025, requiring assessors to measure every window individually, record detailed room-in-roof data, and capture ventilation and renewable technology inputs. This produces more accurate scores and more specific improvement recommendations.
Will the new EPC rules become law?
The government’s January 2026 response confirmed the policy direction, but the legislative changes require Parliamentary approval through primary and secondary legislation. Landlords should follow GOV.UK for updates on when the statutory instruments take effect.
What is the minimum EPC rating for renting in 2026?
The current minimum remains EPC band E under the existing MEES rules; properties rated F or G cannot be let without a valid exemption. The requirement to reach EPC C applies from 1 October 2030, with a grandparenting provision for properties achieving C before 1 October 2029.
What are the EPC changes expected in 2027 and beyond?
New-style EPCs based on the Home Energy Model are anticipated in the second half of 2026. From 2030, the standard shifts to a dual-metric requirement covering fabric performance and a secondary heating or smart readiness standard. Landlords should monitor GOV.UK for HEM methodology updates and secondary legislation timelines.
What is the £10,000 cost cap and how does it protect landlords?
The £10,000 cost cap limits the amount a landlord must spend per property to comply with the 2030 standard. Costs of EPCs and reasonable assessment fees count towards the cap, and spend from 1 October 2025 is included. If the cap is reached without achieving EPC C, a 10-year exemption can be registered on the PRS Exemptions Register.