Yeah it’s a bit shitty right now… I applied… 2k with the 7.5k grant (so the bare cost is 9.5k!). Not cost effective but… wanted to do my bit.

However, I couldn’t go ahead, it just didn’t make sense.

To get the grant all rooms must be heated, and the cost of required adaptation of my bathroom to add a radiator of the required size was somewhat eyewatering…
Heat pumps must not cool, otherwise they’re not eligible, so I’m still on the hook for AC at some point (given how hot it’s getting) which is stupid given they’re basically the same tech.
Planning rules state that heat pumps are only permitted development within a very specific set of conditions, and because of the noise they make I would have to get planning permission at my own expense (and my neighbours already complain if we talk too loud so likelihood of actually getting it very low).

And, specific to the installer I was using (Octopus)…

They wanted to install a 1mx1m water tank. That won’t fit in the airing cupboard (not even close) so they suggested the kitchen… making it difficult or impossible to open the back door…
Their heat pump (daikin) is about 2m wide. My house is only 7.5m wide, you take off 1m each side for the legal thing where heat pumps have to be 1m from the neighbours boundary, space for the door, some drainage… the only position they could suggest was the middle of the back yard…