Thought I’d start a thread on this partly to see if anyone else is interested in chatting about it and partly just to limit my posts on the subject to a single place 
I’ve been doing a fair bit of work over the last few months (and to an extent years) on monitoring and automation at home. All (as much as possible) non-cloud, non-proprietary and for the most part from scratch rather than installing something like Home Assistant (which I should look at again, to be fair).
Water Metering
We had a water leak for a while and to try to monitor and detect this kind of thing in future I’ve put put a pulse counter on the mains water meter. I figured someone might be interested in it so here’s what we’ve got.
The water meter (supplied by SES Water) is an Elster V110. When looking for DIY options for reading it I found out that they actually produce a (somewhat expensive but simple) pulse meter which can be retrofitted:
https://www.johnsonvalves.co.uk/shop/pr6-pulse-module/
It’s electronic rather than a reed switch and is powered by a battery. It supplies signals of various sorts on six different wires but the simple 80ms count pulse is easy to read from a microcontroller, so that’s what we’ve got. So far it seems pretty accurate – as you’d hope. If anyone’s interested in photos or code I can update this.
I’ve also put a meter into the pipe feeding the outdoor taps so that I can separate out usage in the garden from usage in the house and, in future, hopefully control a solenoid valve and watering system while monitoring precisely how much water has been used.
Gas and Electricity Metering
We’re on SMETS2 smart metering here so we’ve got half hourly readings provided after the fact by Octopus’s API. We’ve also got panels (Trina/SolarEdge) and a battery (GivEnergy – avoid) so that gives us more fine-grained readings. I’m probably going to investigate putting CT clamps on some of the more interesting circuits in the house at some point.
I’ve seen that Hildebrand’s smart meter IHD now offers the ability to post in realtime to (local or cloud) MQTT so I’ve ordered one of those to try. Sadly it seems that gas readings are still going to be half-hourly, so I’m pretty much out of ideas for how to monitor that in fine detail.
I saw that @wamonite had done some boiler automation a while back (Budget boiler automation). Anyone else doing much in this space?
