Client overview
This case study examines the solar installation carried out at a semi-detached bungalow in Hull, East Yorkshire. Starting from a respectable D-rated Energy Performance Certificate, the property was upgraded to the highest possible rating of A, alongside a 44.4% reduction in annual energy bills — showing that even a home starting from a mid-range efficiency rating can achieve a top-tier EPC score and substantial cost savings through a well-designed solar PV installation.
The challenge
With a D-rated EPC, the Hull bungalow was already performing reasonably well compared to older housing stock, but the homeowners were keen to go further, reduce their reliance on grid electricity, and bring their bills down in the face of rising energy prices. The challenge was to identify a solution capable of pushing the property all the way from a mid-table D rating to the top A band, while delivering a meaningful, measurable reduction in day-to-day running costs, all within the constraints of a semi-detached roof space.
Project goals
Reach the top EPC band
Push an already-reasonable D rating all the way to the highest achievable A band.
Reduce grid reliance
Generate renewable electricity on site to directly offset the property's grid consumption.
Deliver measurable savings
Bring bills down meaningfully in the face of rising energy prices, within the constraints of a semi-detached roof space.
The solution
10-panel solar PV array
A 4.45kW solar PV system was specified as a single 10-panel array, installed to maximise use of the available roof space and generate high volumes of renewable electricity throughout the year.
Single-array configuration
Designed for straightforward installation and optimal panel orientation, ensuring consistent generation across daylight hours — matched to the property's existing efficiency levels to significantly reduce imported electricity.
Results & benefits
EPC improvement
The property's EPC rating rose from D to A — the highest achievable rating — demonstrating the scale of improvement a well-sized solar installation can deliver even on an already reasonably efficient home.
Annual bill savings
Annual energy bills fell by 44.4%, providing the homeowners with significant, ongoing savings and a much-reduced dependence on grid electricity.
Solar alone, strong results
A single, well-designed solar array unlocked substantial further savings and the highest possible EPC rating, even from a reasonable efficiency baseline.
“The Hull semi-detached bungalow shows that solar PV alone can deliver a transformative result when properly sized and positioned, taking a D-rated property to a top A rating while cutting annual bills by 44.4%. For homeowners already starting from a reasonable efficiency baseline, this case demonstrates that a single, well-designed solar array can still unlock substantial further savings and the highest possible EPC rating.”
YEERS Project Summary, Semi-Detached Bungalow, Hull
