Upgrade D & E Rated Social Housing Properties to EPC Band C

We lodge around 60% of existing D or E rated social housing properties into EPC Band C, for no more than the cost of an EPC Survey.

Case Study: Red Kite Community Housing

We are currently checking Red Kite Community Housing’s (formerly Wycombe District Council’s housing stock) 1,176 EPC D & E rated properties and have found and lodged a large number of D and E rated properties up into EPC Band C, without Red Kite having to make any energy efficiency improvements.

This has been possible because a large number of properties have been incorrectly lodged in D & E band when they should have been lodged in Band C at the time the EPC survey was carried out.

Work completed since 16th September 2025

Delta Surveys has been lodging new upgraded EPCs from D or E up into EPC Band C since 16th September 2025.

Careful analysis ensures no (or very few) new EPC surveys will be carried out, or loft insulation upgraded, on D rated properties which will remain in D band (for example, where loft insulation has already been upgraded since the EPC survey was carried out, or where increasing loft insulation to 300mm+ still won’t achieve Band C).

Delta Surveys will not carry out an EPC survey on such properties, as illustrated in the attached Red Kite feedback spreadsheet.

For clarification: please click on the “Still D if Loft Insulation is upgraded or has been upgraded“ cells in Column L.

View the Red Kite feedback spreadsheet

The objective is to upgrade properties from D or E to C simply by carrying out a new EPC survey, as many will have had loft insulation upgraded since the last EPC survey was carried out.

In some cases the loft insulation would not have been upgraded, but if upgrading to 300mm does not achieve Band C, Delta Surveys will not carry out an EPC survey on that property or upgrade the loft insulation unless specifically required to do so.

There’s no point replacing a valid D rated EPC Certificate with another D rated EPC Certificate.

Outcome of Analysis: Sample of 50 Barnet Homes Properties

The spreadsheet below identifies 14 out of 50 Barnet Homes properties (28%) that would be upgraded from D or E up into EPC Band C simply by having another EPC survey carried out.

Common Problems & Our Solutions

Problem: Cloning EPCs

Most EPC surveys for social housing properties are cloned, especially by larger EPC survey providers, resulting in a disproportionate number of EPCs being lodged in band D or E when they should be in Band C.

The practice of cloning allows large numbers of properties to not even be visited, which inevitably results in properties being lodged in the wrong EPC band (usually band D when they should be in band C).

Solution

We never clone EPCs. Every individual property is visited and assessed as standard practice.

By physically checking cavity walls for insulation and checking the depth of loft insulation in each and every property, Delta Surveys can upgrade existing loft insulation to 300mm+ (or insulate cavity walls where required) if it’s the only way to upgrade to Band C from D or E.

Loft insulation upgrades are usually only required if existing D rated EPCs cannot be upgraded to Band C simply by having a new EPC survey carried out.

Problem: Not Checking the Depth of Existing Loft Insulation

Many properties are D rated when they should be in band C because assessors (especially from larger providers) don’t check loft insulation depth. The EPC software then defaults to:

Roof: Pitched, No insulation (assumed) – Very Poor
Roof: Pitched, Limited insulation (assumed) – Poor

This gives the property a lower EPC rating than it should be.

In many cases there is 200mm or 300mm of existing insulation, which would have put the EPC in C band instead of D (if only the loft had been checked).

Solution

We check the depth of existing insulation in EVERY loft. This alone upgrades large numbers of properties from Band D to Band C by correctly recording/documenting the existing loft insulation thickness and lodging a new EPC.

Problem: Loft Insulation in Blocks of Flats Is Very Rarely Checked

EPC assessors rarely check loft insulation in blocks of flats, citing “no access”. This results in thousands of top-floor flats being D or E rated when they should have been lodged in Band C.

Without checking and recording loft insulation depth, EPC software defaults to:

No insulation (assumed) – Very Poor
Limited insulation (assumed) – Poor

Depending on property age, this produces D or E ratings when, in the vast majority of cases, properties should be Band C because there is some level of insulation in almost all lofts.

Solution

We gain access to, check, and provide photographic evidence of loft insulation depth for EVERY loft in blocks of flats (and for all other property types), via individual loft hatches or communal loft hatches after obtaining keys/key codes where necessary.

Problem: Logistic Challenges with Installing Loft Insulation

Many lofts still have inadequate insulation because contractors will not insulate unless storage is removed by the tenant and there is clear access to the loft floor area.

Contractors also typically won’t tidy or re-lay existing insulation, move storage, or remove and replace stored items.

Solution

We go the extra mile by tidying/re-laying existing insulation before adding more, and we move or remove and replace storage if the tenant is unable or unwilling to do so.

See before & after photos of a recent loft insulation upgrade:

View the loft insulation upgrade photo set

Problem: Cavity Wall Insulation Not Properly Evidenced

There is no requirement for EPC assessors to drill into an external cavity wall to confirm insulation, so they often don’t.

If assessors can’t see evidence of cavity fill drill holes (many don’t look), EPC software defaults to:

Cavity wall, no insulation (assumed) – Very Poor
Cavity wall, partial insulation (assumed) – Poor

Because around 90% to 95% of cavity wall properties in England & Wales are insulated, many properties are incorrectly recorded with poor energy efficiency.

Solution

Delta Surveys EPC Assessors drill and take GPS-tagged, time & date-stamped bore scope photos inside cavity walls, providing evidence that walls are insulated, even if the existing EPC says there’s no insulation.

In the rare cases where cavity walls are empty, Delta Surveys can arrange for an IAA (Insulation Assurance Authority) registered and licensed cavity wall installer to insulate the walls if required to achieve EPC Band C.

Photographic Evidence: Loft Insulation Upgrades to 300mm+ (Before & After)

17 Holywell Gardens, High Wycombe, HP13 7NA
View photos
1 Cater Road, Lane End, High Wycombe, HP14 3JD
View photos
5 Denham Road, Lane End, High Wycombe, HP14 3LE
View photos
NB: In the pre-install photos, loft rubbish/storage was removed/cleared by the installers prior to upgrading to 300mm+ (as shown in the post-install photos).

Process: Facilitating Site Surveys

Once Delta Surveys identifies addresses that are in an incorrect EPC band (usually D or E), a letter needs to be sent to residents informing them they will be contacted by Delta Surveys (similar to the letter Red Kite Community Housing sends to General Needs residents).

We would email a list of between 50 and 100 properties identified as being in the wrong (lower) EPC band each week, asking for a letter (based on the above) to be posted so site surveys can be arranged with residents.

Summary

On average, around 60% of D or E rated social housing properties can be upgraded into EPC Band C simply by carrying out another EPC survey.
An additional 10% to 15% can be upgraded from D or E to Band C by upgrading loft insulation to 300mm+ / 350mm.
D, E & F rated properties with an expired EPC would also be upgraded into Band C, with only a few remaining in Band D.

If this unique EPC service may be of interest, please contact us at your earliest convenience.