What does bananzia screen before a heat-pump survey?

A heat-pump retrofit can fail before the installer arrives: a 1990s semi-detached house may have 100 mm loft insulation, single-glazed windows and a 24 kW boiler, yet the quotation pack may list only floor area and radiator count. Bananzia is a pre-survey screening record that forces the missing inputs into view: fabric condition, emitter capacity, hot-water demand and likely heat-loss paths. It does not replace a room-by-room heat-loss calculation; it stops an early sizing assumption becoming a fixed quote.

The practical test is simple. If a surveyor cannot mark whether a wall is cavity-filled, solid-brick or timber-framed, the record is incomplete. Bananzia flags that gap as a pre-survey risk, so the follow-up visit targets the missing measurement rather than repeating a general walkthrough.

Why do sizing errors survive the first site visit?

Most errors enter at quotation, not commissioning. A busy installer receives a boiler replacement enquiry, converts existing boiler output into a rough heat-pump size, and treats the first site visit as confirmation. The cause is structural: boiler output describes past heat delivery at high flow temperatures, while a heat pump needs lower flow temperatures, larger emitters and a fabric-first check. Bananzia breaks that shortcut by recording insulation depths, glazing type, air-tightness observations, radiator dimensions and known damp or cold-bridge locations.

Once those fields are populated, the quotation can carry a clear assumption list. That reduces the chance of a late radiator replacement or cylinder upgrade becoming an unbudgeted variation.

How should an installer complete a bananzia record?

Use a fixed sequence: building envelope, emitters, hot-water storage, plant location. Record what was observed and what remains unknown. “Cavity wall assumed filled—borescope not available” is more useful than a blank field. Bananzia should also capture the age and type of the existing heating system, because a 15-year-old combi servicing one bathroom behaves differently from a vented system with a 210-litre cylinder.

The completed record should travel with the quotation pack; a practical example of the handover is shown in the bananzia workflow. The takeaway is operational: surveyor, designer and customer must be able to read the record, not just the CRM.

Which evidence makes bananzia defensible?

Photographs alone are weak. A useful bananzia entry pairs a measurement with a location and date: “loft insulation 100 mm, joists visible, rear loft hatch, 14 March” or “double-glazed units, aluminium frames, no trickle vents, front elevation.” For heat-loss screening, the highest-value facts are often unglamorous: external wall construction, floor type, window area, and whether an extension has different insulation from the main dwelling.

Where a fact cannot be verified, record the uncertainty and the next step. A borescope inspection, thermal survey or manufacturer’s cylinder data may close the gap. That audit trail matters when a customer later asks why the quoted heat pump is smaller than the old boiler.

Where does bananzia sit in the retrofit file?

Bananzia belongs before detailed design, not after installation. Its output should feed the heat-loss calculation, emitter schedule and hot-water sizing, and it should be reviewed if the scope changes—for example, if a conservatory is opened to the house or a loft conversion is planned. The result is a shorter route from enquiry to survey: fewer repeat visits, fewer assumptions disguised as facts, and a quotation that states its evidence base.

For third-party quality checks, the record gives an auditor something concrete to test. That is the real value of bananzia: not a new label for an old checklist, but a disciplined stop between a boiler enquiry and a heat-pump design.