I've just had an Octopus heat pump survey done, and it seems likely that the approach being taken by Octopus will result in most surveys not resulting in actual installations.

Octopus seem to be pursuing a one-size-fits-all strategy. I was told that the only heat pump they are currently installing is the Daikin Altherma 3 R Monobloc, which is available in 9kW to 16kW versions. The heat loss for my house was calculated to be 5.3kW, so the output from the heat pump would be almost double what is needed and prone to producing short cycling. This is probably the situation in many houses, so it is not surprising that Octopus seem to be installing buffer tanks as standard in all installations.

Although we have space for a buffer tank and the larger hot water cylinder that is needed, many "standard homes in London, the midlands and the south east" may not. And Octopus are apparently not doing installations of tanks in the loft, so that is not an option.

Issues such as this mean surveys may not be finished or acted on, either because Octopus considers the installation to be too "complex", or because the customer rejects it when they discover the space needed.

If Octopus made it clear to potential customers, before doing a survey, that space would be needed for a buffer tank and large hot water cylinder, and that they will not install heat pumps that are visible from the road (see this post), then a lot of wasted time (Octopus's and customers') could be avoided.