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Understanding SAP 10.2 requirements: Increasing energy efficiency ratings in new flats with solar

Picture of Allume By  Allume  ·  5 minute read

The Energy Performance Certificate (EPC) score is the industry standard for measuring how energy-efficient a home is. Essentially, it assesses how much energy a property uses to operate and how much grid energy it relies on. An EPC score gives a clear indication of a building's energy performance, sustainability, and the estimated costs of running it. 

Given the importance of EPC ratings in assessing a property’s energy efficiency and sustainability, it’s crucial to understand how these scores are calculated and how new regulations like SAP 10.2 impact them.

MKM Developments - New Build-1

Image: SolShare project with MKM Developments achieving a building of net-zero flats. See our case study.

Understanding EPC and the role of SAP assessments
The ECO4 scheme (Energy Company Obligation) aims to improve energy efficiency in residential homes across the UK, with a particular focus on low-income and vulnerable households.
  • Target Properties: Focuses on upgrading properties rated in energy efficiency bands D to G.
  • Funding: Allocated with a budget of £4 billion to assist eligible households in making energy-saving improvements.
  • Duration: Scheduled to run until  March 2026, it represents the fourth iteration of the scheme.
  • Eligibility: Primarily targets low-income, vulnerable, and fuel-poor households, offering support to make their homes warmer, healthier, and more affordable to heat.
  • Benefits: Includes improvements like insulation, heating upgrades, and the installation of renewable energy technologies to reduce overall energy consumption and carbon emissions.

To generate an EPC, a Standard Assessment Procedure (SAP) assessor conducts a detailed evaluation of the home, examining various factors such as the type of heating, insulation, glazing, and the materials used in the building’s construction. The SAP score, which ranges from 0 to 100, directly influences the EPC rating, categorising homes from A (most energy efficient) to G (least energy efficient).

One key component in a SAP assessment is the source of the home’s energy. Homes that utilise renewable energy sources, such as rooftop solar PV systems, often achieve higher SAP scores due to their reduced reliance on grid energy. This makes solar PV a powerful tool for improving both SAP scores and EPC ratings.

The shift from SAP 2012 to SAP 10.2
The ECO4 scheme (Energy Company Obligation) aims to improve energy efficiency in residential homes across the UK, with a particular focus on low-income and vulnerable households.
  • Target Properties: Focuses on upgrading properties rated in energy efficiency bands D to G.
  • Funding: Allocated with a budget of £4 billion to assist eligible households in making energy-saving improvements.
  • Duration: Scheduled to run until  March 2026, it represents the fourth iteration of the scheme.
  • Eligibility: Primarily targets low-income, vulnerable, and fuel-poor households, offering support to make their homes warmer, healthier, and more affordable to heat.
  • Benefits: Includes improvements like insulation, heating upgrades, and the installation of renewable energy technologies to reduce overall energy consumption and carbon emissions.

Under SAP 2012, apartment buildings could install a large rooftop PV system connected to the landlord supply, which powered communal areas like hallways and parking gates. This setup allowed every flat in the building to benefit from an uplift in their SAP scores and EPC ratings, despite the solar energy primarily serving the landlord's needs. However, this system had a critical flaw: it did not reduce individual flats' reliance on grid energy or lower their electricity bills, as the energy generated was funnelled through the grid before reaching the apartments.

Recognising this issue, the government introduced SAP 10.2, which no longer allows a single landlord PV system to contribute to SAP scores. Instead, for flats to receive a SAP score uplift, the solar PV must be directly connected to each unit, bypassing the landlord meter. This direct connection ensures that solar energy is utilised within the flat, reducing its grid dependency and lowering energy costs.

The challenge of SAP 10.2 compliance
The ECO4 scheme (Energy Company Obligation) aims to improve energy efficiency in residential homes across the UK, with a particular focus on low-income and vulnerable households.
  • Target Properties: Focuses on upgrading properties rated in energy efficiency bands D to G.
  • Funding: Allocated with a budget of £4 billion to assist eligible households in making energy-saving improvements.
  • Duration: Scheduled to run until  March 2026, it represents the fourth iteration of the scheme.
  • Eligibility: Primarily targets low-income, vulnerable, and fuel-poor households, offering support to make their homes warmer, healthier, and more affordable to heat.
  • Benefits: Includes improvements like insulation, heating upgrades, and the installation of renewable energy technologies to reduce overall energy consumption and carbon emissions.

While SAP 10.2’s direct connection requirement enhances energy efficiency, it also presents significant challenges for housing associations, property developers, homeowners, and SAP assessors. Traditionally, installing separate solar PV systems for each flat in a building is complex, costly, and impractical. This method requires extensive DC cabling, the installation of inverters in each flat, and careful allocation of panels based on roof orientation—complicating the process and potentially leading to unequal energy distribution among the flats.

The SolShare solution 

SolShare offers an innovative solution to the challenges posed by SAP 10.2. As the world’s only technology capable of directly connecting multiple flats to a single rooftop PV array, SolShare streamlines the installation process, reducing complexity and cost. By using SolShare, solar energy can be efficiently distributed to each flat, ensuring maximum SAP score uplift and optimal EPC ratings for all units within the building.

What sets SolShare apart is its ability to allocate precise amounts of solar energy to each flat, down to 10 watts, allowing SAP assessors to fine-tune their calculations and achieve the desired EPC rating. This level of precision is unmatched by any other energy efficiency measure, making SolShare an invaluable tool for SAP assessors navigating the new SAP 10.2 regulations.

New build blog - SAP assessor

Image: SoShare project with TopHat which connected 90 flats at Kitchener Barracks in Kent, UK.

Case Study: How SolShare gets the most from your solar PV system

Modular House builder, TopHat, faced a challenge in achieving EPC B ratings for all flats in one of their residential developments, despite implementing various energy-saving measures. The limitations in specifying energy contributions and the costs of additional improvements made it difficult.

However, with SolShare they were able to allocate the specific kWp associated to each flat, adding the necessary SAP points to bring them all from a varying EPC C to a level EPC B. The table below shows how TopHat achieved this.

TopHat table-2

*Approx. yield from 33kWp system as calculated using SAP methodology (pessimistic).
**kWh per year required for ADL1A 2013 block compliance.
***kWp required per type to boost EPC rating to ‘B’. Also sufficient to achieve ADL1A 2013 block compliance
****In reality two of this type will not receive PV energy in order to limit system to 2 no. SolShare (2 x 15 feeds).

 

The benefits of SolShare to New Build and Retrofits:

Reducing carbon intensity and improving DER:

    • Solar distribution to individual units: SolShare enables solar energy to be shared across all the individual dwellings as well as common areas (landlord areas) within a building. By distributing the solar energy to each apartment, the overall carbon emissions from the building are reduced. This reduction in emissions positively impacts the Dwelling Emission Rate (DER), which is a crucial factor in complying with Part L of the building regulations.
    • Building carbon compliance: By lowering the carbon intensity of the building as a whole, it becomes easier for the entire building to comply with carbon-related building regulations. Even though energy is distributed among individual dwellings, the building as a whole benefits from reduced carbon emissions, making it simpler to meet the required standards – This is especially effective when the landlord's energy supply is also integrated.

Supporting SAP rating through running costs:

  • Impact on running costs: SAP ratings are also concerned with the running costs of a building, which reflect the cost of heating, lighting, and hot water provision. Since SolShare allocates solar energy to individual flats, the energy costs for each apartment are reduced. This reduction in energy costs improves the SAP rating because lower running costs contribute to a higher SAP score.

 

Benefit to building compliance:

  • Combining DER and running costs: The unique advantage of SolShare is that it doesn't just reduce the carbon footprint of the building (DER) but also lowers running costs for each individual unit. This dual benefit means that a building with SolShare technology can simultaneously improve its carbon emissions profile and its SAP rating, leading to easier compliance with Part L of the building regulations.

 

The introduction of SAP 10.2 has brought about significant changes in how energy efficiency is assessed in apartment buildings. While these changes present new challenges, SolShare offers a unique and effective solution to navigate these complexities. By simplifying the installation process, reducing costs, and optimising energy distribution, SolShare enables SAP assessors to achieve the highest possible EPC ratings and ensures that apartment buildings meet the new energy efficiency standards in the most straightforward and cost-effective way - making it valuable for both new builds and retrofits.

 

Get a free assessment of your portfolio

Book an appointment with our experts today - they will provide a free assessment for your project that will demonstrate the SAP uplift for each flat and indicative costs.

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Share this information with your network to help others take advantage of this fantastic opportunity. Together, we can make a significant impact on energy efficiency and fuel poverty in the UK.