From 38F to 83B: An Environmental Enthusiast’s ECO4 Energy Overhaul
West Stow, Suffolk | October 2025 Installation
Complete System: Knauf Loft Roll 44 loft insulation, Panasonic Aquarea T-CAP Monobloc 9 kW Air Source Heat Pump, a Joule Cyclone 200L Indirect hot water cylinder, Panasonic controller, TRVs and 9 x Trin 450W solar panels
Motivation: Fossil-Free and Future-Proofing
*Please note that the ECO4 scheme is coming to a close on 31st March 2026. The experience and project mentioned in this case study may no longer be available in the same capacity.
For this Suffolk homeowner and ECO enthusiast, the decision to pursue a comprehensive energy overhaul—including Loft Insulation, an Air Source Heat Pump (ASHP), and Solar PV—was rooted in a powerful collection of goals. The primary motivation was the commitment to "remove our reliance on fossil fuels”, signalling a clear desire for energy independence and a greener footprint. Crucially, the project was also driven by the ambition to enhance the property's value and efficiency through upgrading its EPC rating, which was successfully achieved: the property started at a dire 38F and after the completion of the project, was assessed to have an EPC rating of 83B.
Coupled with the practical aim to "save money" on future running costs, the installation of these measures and being able to have it all done for FREE through the ECO4 scheme, made the decision to go ahead an easy one to make.
Key Points:
1. EPC uplift from 38F to 83B 2. Installation of loft insulation, ASHP and Solar PV, reduces energy required to heat the house and also reliance on high-cost grid electricity. This achieves the homeowners goals of "removing our reliance on fossil fuels" and "saving money".
The Essential First Step: Fabric First and Loft Insulation Top-Up
Did you know that approximately 25% of heat is lost through an uninsulated roof?
The first measure undertaken in this property was a Loft Insulation top-up, adhering to the crucial "Fabric First" principle in ECO4 projects. By taking this approach, we reduced the demand for heating as the building's physical envelope became optimised before installing the Air Source Heat Pump allowing it to operate more efficiently, saving money and increasing system longevity.
The existing insulation, measuring approximately 100mm, was topped up to 300mm to meet current PAS (Publicly Available Specification) standards. The product utilised for this measure was Knauf Loft Roll 44 which is a lightweight, non-combustible mineral wool quilt designed for pitched roofs and lofts that has a thermal conductivity of 0.044 W/mK.
Additionally, part of the loft area was boarded to maintain usable storage space for the homeowner, raised above the insulation to ensure the full insulation depth was maintained across the entire loft space.
Finally, to prevent issues with condensation and dampness after significantly increasing the insulation, felt lap vents were installed. These vents are essential for maintaining adequate airflow in the loft space, allowing moisture-laden air to escape, ensuring the insulation and roof timbers remain dry and effective. This preventative measure ensures the long-term health of the roof structure and the performance of the new insulation.
The Heart of the Overhaul: Fossil-Free Heating
With the building’s fabric optimised, the next step was to replace the fossil-fuel reliant system with a highly efficient ASHP. After our pre-installation building inspections were conducted, our Senior Heating Engineer performed accurate, property-specific heat loss calculations, which allowed us to select the most appropriate and efficient model of ASHP to meet the home's reduced heat demand.
A Panasonic Aquarea T-CAP Monobloc 9 kW heat pump was installed, integrated with new, appropriately sized radiators and kick space heaters throughout the property. Crucially, the installation also included advanced heating controls—a Panasonic Controller and Center brand TRVs (Thermostatic Radiator Valves)—allowing the homeowner to manage room-by-room temperatures and maximize the system’s efficiency and comfort.
Completing the Power Picture: On-Site Generation with Solar PV
The completion of the energy overhaul involved installing a 4.05kW Solar PV system, built using 9 x Trina Solar Co.Ltd. 450W solar panels managed by a Solax X1 Boost G4 inverter.
The primary role of the PV array was to generate clean electricity on-site, directly addressing the operational costs of the new ASHP and by doing so, shielding the homeowner from volatile grid electricity prices. This strategic coupling of high-efficiency heating and clean power generation is what resulted in the massive success of the project, elevating the property's energy efficiency rating from a 38F to the impressive 83B result.
The successful delivery of this comprehensive ECO4 project resulted in a total transformation of the Suffolk property. By meticulously adhering to the "Fabric First" principle, installing a high-efficiency Air Source Heat Pump correctly sized to the home's reduced demand, and integrating a Solar PV array for energy generation, the homeowner achieved all of their primary goals.
The property is now functionally independent of fossil fuels, fully future-proofed against rising energy costs, and delivers significant savings on annual running costs.
Crucially, the outcome validates the effectiveness of the ECO4 scheme in driving substantial, permanent home efficiency improvements, evidenced by the impressive shift from a 38F EPC rating to a 83B - a result that offers enhanced property value, superior comfort, and a greener footprint for decades to come.
Lasting Impact
Despite it finishing in March 2026, those that were lucky enough to benefit from the ECO4 scheme will forever remember the impact it has on their daily lives.
Here at Projects4Renewables, we strive to help those in our own communities. If you are looking for a council-endorsed, one-stop shop for retrofit works who have all teams employed in-house, contact us today to start your journey to a cleaner, greener future.
