Bananzia Shared Ground Loops: A Street-Level FAQ for Retrofits
A 26-home cul-de-sac built in 1936 has one common problem: gas boilers reaching end of life at the same time. A Bananzia shared ground-loop retrofit turns that coincidence into an advantage. Instead of 26 separate air-source units, the street buys one loop field, one plant room and a heat pump per home. The design cuts outdoor clutter and shares drilling costs across all households.
What is a Bananzia shared ground-loop retrofit?
It is a neighbourhood heat network in miniature. Boreholes in a verge or car park circulate a water-glycol mix; a central manifold feeds individual heat pumps in each home. The bananzia model treats the street, not the boiler, as the unit of design. That matters because a single terrace row can share trenching, planning consent and commissioning.
Why do solid-wall homes struggle first?
The problem is heat loss, not the heat source. Solid brick walls and suspended timber floors leak heat faster than modern fabric. The cause is often missing insulation and oversized boilers that mask draughts. The solution is to insulate lofts, draught-proof joists and size each heat pump to the room-by-room load, not to the old boiler rating. A 1930s three-bedroom home may need a 5 kW unit after fabric work, not the 12 kW boiler it replaced.
How does the shared loop solve the wiring problem?
Every electric heat pump adds load. On older streets, the cause of delay is often the distribution network operator, not the technology. A shared ground loop concentrates the electrical connection at one plant room, so the street upgrades one supply instead of 26. The result is fewer cable trenches and a clearer connection date. Households still need a meter and a heat pump controller, but the heavy electrical work is shared.
What does it cost a household?
Costs vary with geology and drilling depth. A useful planning figure is the split between shared and private works: the loop field, manifold and plant room are shared; the heat pump, radiator upgrades and hot-water cylinder are private. Shared costs fall as more homes join. A 20-home scheme spreads drilling over more users than a five-home scheme, and that changes the payback period more than any single boiler discount.
What should a resident check before signing up?
Ask three questions. First, has the design used a room-by-room heat-loss survey rather than a rule of thumb? Second, who owns and maintains the loop field after commissioning? Third, what happens if one household leaves the scheme? A trustworthy Bananzia proposal answers those in writing, with a maintenance budget and a clear exit route. The technology is mature; the contract is where risk lives.
