The cold Sunday that started the audit
The Sunday tea service at Marsh Lane Village Hall ran in coats. A wall thermometer near the kitchen hatch read 13°C at 3 p.m., while the electric storage heaters had been charging since midnight. The hall’s winter bill for the previous year was £2,840, and bookings for January had fallen by six dates. The problem was not one failed appliance. It was a building envelope that leaked heat faster than the heaters could replace it, especially around the 1930s single-glazed sash windows and the propped-open fire door.
What the bananzia survey measured
A volunteer team spent two Saturday mornings on a room-by-room survey. They followed a simple bananzia template: record air temperature at seated height, note draught paths with a tissue, photograph radiator positions, and log when each room is actually used. The results were specific. The main room lost heat through two window bays and an uninsulated loft hatch; the committee room stayed warmer because its door was kept shut; the corridor acted as a wind tunnel between the front entrance and the fire exit. The cause was not mysterious. The hall had never had a zoned heat plan, so every heater ran on the same schedule regardless of occupancy.
Three fixes that paid back first
- Draught lobby: A heavy curtain across the front doors, fitted with a magnetic breakaway strip, cut measured draught speed at the noticeboard from 1.8 m/s to 0.6 m/s. Cost: £140.
- Window bays: Secondary glazing panels on the two coldest bays raised the 7 a.m. temperature by 2.4°C without blocking the sash opening. Cost: £620.
- Zoned schedule: The caretaker set storage heaters to charge only before booked events, with the committee room dropped to 12°C when unused. The first eight-week comparison showed a 19% reduction in electricity use.
The takeaway is practical: fix air paths before replacing heat sources. The hall’s storage heaters were old but not the first bottleneck.
What other halls can copy
Marsh Lane’s committee now keeps a one-page winter checklist: close the fire door, draw the lobby curtain after 4 p.m., and record the main-room temperature at the start of each hire. The bananzia survey also flagged a bigger project for next summer: insulating the loft hatch and adding thermostatic radiator valves to the two committee-room radiators. The volunteers did not need a consultant to start. They needed a repeatable record, a few low-cost interventions, and a booking calendar that matched heat to use. For other community buildings, that sequence is the useful lesson: measure the cold spots, trace the causes, then spend on the fixes that show up in the room, not just on the energy bill.