EPC open data vs Kamma’s (enhanced) EPC data as a source of property emissions data

Mortgage Lenders

Access to EPC data is vital for those in the property sector today.

Mortgage brokers use EPC data to factor energy efficiency into affordability assessments and property valuations during loan origination. Property providers and portfolio managers use EPC data to understand and mitigate transition risk in their portfolios. Many property-related companies also use EPC data as part of their climate-related financial disclosures reporting, especially where financed emissions are relevant. 

But how do they access that data? 

In the past, companies have relied on freely available EPC data from the UK government, through the EPC Open Data website or the EPC register.

Today, companies like Kamma are making it possible to access enhanced EPC data and move away from the limitations of the government’s databases.

Let’s take a closer look at both options as data providers for the property sector.

EPC open data

Until 2016 the primary source of EPC data was the government’s EPC register.

The register enables users to search for the EPC of one individual property. For those in the property sector that regularly need EPC data for a large number of houses, this wasn’t ideal.

Screenshot of the EPC register

In 2016 EPC data was made available in bulk through the launch of the EPC Open Data website, which marked a big step in the right direction in ensuring access to energy efficiency data for the UK housing stock.

Screenshot of EPC open data

However, there are four major issues with using EPC Open Data as a reliable EPC data provider for the property sector:

  1. Missing data
  2. Unvalidated data
  3. Outdated data
  4. Inaccurate data

Missing data in EPC open data

EPC Open Data is not represent a complete dataset on the energy efficiency of UK housing, for a few key reasons:

  • Homeowners can opt out of EPC open data. The government allows homeowners to opt out of their EPC being publicly disclosed via EPC open data and the EPC register, further reducing the proportion of homes included in the database. 
  • EPC open data is not the definitive source. The EPC open data website itself states that the data it discloses ‘should not be relied upon to check if a valid EPC has been produced on sale or rent of a building’ and highlights that the ‘definitive source of EPCs’ is the EPC register, not EPC open data. The implication is that it’s entirely possible for data to go missing between the EPC register and EPC open data, making it an unreliable source of data. 
  • Energy efficiency data for homes in Scotland is not included. EPC data for homes in Scotland is held separately on the Scottish EPC register, and is not included in EPC open data – adding an extra layer of complication for property portfolios that span the whole of the UK. 

Unvalidated data in EPC open data

There’s no quality assurance process in place when the EPC open data is updated, meaning that the data is not checked or validated before it is made accessible to the public.

This means that errors and inaccuracies can creep into the dataset – including common occurrences of mojibake (garbled text that results from encoding errors).  

Outdated data and static baselines in EPC open data

There are two parts to ensuring up-to-date energy efficiency data.

Firstly, are all current EPCs included in the data source?

The EPC register is updated with new EPCs only quarterly, so there can be months worth of EPCs not included at the point of access. 

EPC open data is updated monthly, giving a more up-to-date view. However, there is also a month’s lag, with new data added each month for the month before last, meaning data can still be up to two months out of date at the point of access.

This poses a particular challenge for mortgage brokers and underwriters who might need access to a newly issued EPC during the mortgage origination process.

Secondly, do the EPCs themselves offer an up-to-date view of the energy efficiency of the property they represent?

EPCs last for 10 years once issued. That’s a long time in relation to the energy performance of a home: the homeowner could have made substantial improvements in that time, or the property could have fallen into disrepair. 

Further, the methodology that sits behind EPCs is known to be highly inaccurate

This is in large part because the SAP calculations it uses rely on outdated baselines for vital inputs such as energy prices, carbon intensity factors, and the cost of retrofit improvements such as solar panels – producing energy efficiency ratings and recommendations that are outdated at the point of issuance and even more so after a decade of existence. 

For instance, EPCs use a static baseline of 0.519kg per kwh for carbon intensity – carbon intensity being a measure of kilograms of CO2 emitted per kilowatt hour of energy used.

This is a vast overestimation of the actual carbon intensity of the National Grid, which averages 0.173kg overall.

It’s also a simplification, because in reality carbon intensity of the Grid varies significantly depending on location. 

For instance, Scotland has a large amount of wind farms and offshore wind turbines, meaning a larger proportion of renewable energy is contributing to the Grid in Scotland – lowering the carbon intensity. 

EPCs for homes in Scotland should reflect this reality, but they don’t due to the static baseline used in the SAP calculations.

This is why for the climate data and analysis we conduct at Kamma we integrate directly with the National Grid and use their real-time (half hourly) data on the actual carbon intensity of the grid, to increase the accuracy of energy performance data for property portfolios in the UK.

Inaccurate data in EPC open data

The inaccuracy of EPC data also goes further than the unvalidated data and out-of-date baselines used within the SAP methodology:

  • The SAP calculations return an estimate of the energy costs of heating a home, not its energy efficiency
  • Several default assumptions are included as inputs in the SAP calculations (such as U-values for features like windows), which are known to be highly flawed 
  • The SAP points scoring system is skewed and the final EPC rating is also manually adjusted based on the property size, meaning EPCs for different properties cannot be accurately compared with one another 
  • The methodology relies on energy assessors to gather many of the inputs for SAP calculations e.g. floor measurements, type of heating system used etc – leaving scope for introducing inconsistencies in calculations.
  • Until 2021 EPCs were not issued with a Unique Property Reference Number (UPRN), meaning there is no way to verify that EPCs issued before this date actually refer to the correct property.

All of this results in EPCs themselves being an inaccurate and unreliable source of energy efficiency data for the UK housing stock – which is where an enhanced EPC dataset like Kamma’s comes in.

💡 6 reasons that EPCs are an inaccurate measure of energy efficiency

Looking for more information on the methodology flaws that result in EPCs being an inaccurate source of energy efficiency data?

Head to our article on the topic ➡️

How does Kamma’s data solve the problems of EPC Open Data?

Kamma’s enhanced EPC dataset is specifically designed to offer the most comprehensive, accurate, and up-to-date view of the energy efficiency of and carbon emissions from UK housing.

Comprehensive 

The gaps left in the government’s EPC dataset are filled:

  • Additional energy performance data sources. EPC open data is amalgamated with the Scottish EPC register to give a complete view of available EPCs in the UK. On top of this, we also incorporate data from other sources that offer additional insights on the energy efficiency of UK homes e.g. the National Grid, ECO4 funding reports, etc, creating a single source of truth. 
  • Predictive modelling. For any remaining properties without data we use predictive modelling to fill the gap, built by our expert geospatial engineering team to a high level of accuracy. To give one example, in a recent project for a UK mortgage lender, Kamma was able to accurately model the EPC certificate for 37% more properties than the previous supplier.

Accurate

Inaccuracies in the EPC methodology are improved:

  • Data is checked and calibrated. We verify data across all sources to ensure accuracy. This includes advanced address matching to give confidence that the data you see is for the correct property, despite this not being available on the EPC itself. 
  • Advanced analysis. As well as additional data, we also layer our intelligent analytics on top of our enhanced EPC dataset, enabling us to offer advanced insights to meet the needs of our property sector customers – whether you need to know the % of expired EPCs in your property portfolio or model the costs to achieve EPC C across-the-board as part of your climate transition plan, or something else entirely. 

Up-to-date 

To ensure the most up-to-date view of energy efficiency we:

  • Incorporate every EPC certificate available today. The EPC data in our dataset is constantly updated to reflect new EPCs and updated information. 
  • Calibrate using current baselines. We incorporate the current baselines for vital factors such as carbon intensity factors (from the National Grid) and energy prices (from the energy market) into our data to rectify the outdated nature of the EPC methodology.
  • Automate via an EPC API. Our data can be easily integrated into the existing systems of a property company via an EPC API, meaning the current data is always readily available at your fingertips without needing to re-check the EPC open data website constantly – removing any human error in failing to update internal databases with the latest data. 

Kamma’s enhanced EPC data is available directly through a desktop app or an API, or can be delivered as a bespoke report. 

All available UK EPC data consolidated. Data added from additional sources. Accurate address matching to erase gaps. Predictive modelling to erase gaps. Data calibrated against up-to-date baselines. Intelligent analytics applied for more insights.

”Kamma’s proposition was unique: combining the best available data with the strongest available analysis. As a result of our partnership, we have a stronger view on the energy performance of our back book than ever before, with models that are more accurate than any we’ve used previously. This will be invaluable in shaping how we approach our net zero and transition risk management strategies.” 

Tom Kenny, Group Property & Risk Director, Just Group Plc

The dataset has also been used to develop the Kamma Retrofit Explorer tool, giving homeowners a reliable source of information on the costs and ROI of energy efficiency improvements to kickstart the green mortgage market. 

Screenshot showing the opening screen of Kamma's Retrofit Explorer – enter your address to get started.

“We want to offer genuine incentives to customers seeking to borrow in order to improve their home. We’re delighted to partner with Kamma who can also illustrate further benefits from making positive changes. Together we’re aiming to drive genuine change for our customers.”

Steve Matthews, Head of Residential Lending at Octopus Real Estate

📊 Harness Kamma’s EPC data to support your goals

Whether you need to mitigate risk in a property portfolio, understand the highest-impact ways to accelerate your company’s progress towards net zero targets, or increase the uptake of home retrofit amongst your borrowers, we’re here to help.

Get in touch ➡️

Share this article

Read more recent articles

A climate transition guide for small and mid-sized mortgage lenders

Small and mid-sized lenders face unique challenges when it comes to the climate transition. Constrained budgets, few ESG leads, and less regulatory pressure than experienced by larger lenders; there are…

Read more

PCAF data quality scores: Best practice for mortgage lenders

As climate regulations tighten and scrutiny on financial disclosures intensifies, mortgage lenders are under increasing pressure to measure and disclose the climate impact of their loan portfolios accurately.  The Partnership…

Read more
Merton Property Licensing

The Transition Plan Taskforce (TPT), explained for mortgage lenders

As new regulations reshape the UK’s financial sector, mortgage lenders must adapt to evolving climate-related requirements and ensure they are contributing meaningfully to the net zero transition.  The UK Transition…

Read more