MortarThePoint

That makes sense when it's a surface mounted consumer unit, but when it's a flush mounted one it extends behind the plasterboard. The wall construction is 4x2 studs with plasterboard, VLC (300ga polyethylene), Knaug Omnifit insulation slabs between the studs and behind. I was thinking I could build a box in between a couple of studs and then airtight that and have the VLC taped to it. That would effectively create the 'bump' in the airtightness layer needed to accommodate the rear part of the flush mounted consumer unit.

I've agreed with the sparky that I am going to have a satellite consumer unit (CU) for an attic conversion. That way, I have a single feed to the attic and then dedicated isolator, RCBOs etc for the attic sockets, fans and lights etc. I am planning to put a flush mounted consumer unit into a stud wall that has an airtightness requirement. I'm not expecting to achieve airtightness with the CU itself[1], so am thinking I'll create an OSB box behind the plasterboard that is lined with Passive Purple (air tight paint) and has sealed entries for the cables. The airtightness membrane of the wall would then get tape sealed to this OSB box. Is that how airtightness is normally done for flush mounted consumer units? I like the look of the flush mounted consumer unit below. I know Hager also make a good one, but I feel it's a bit industrial looking for being visible on a wall in living space. Hopefully this one doesn't actually have the logo on it, but if it does a pit of paint could easily solve that. Has anyone used a Live brand consumer unit? [1] I know Wiska do airtight cable grommets you can get from TLC, but attaching the membrane to the CU housing sounds tricky. https://www.electrical4less.co.uk/product/live-electrical-fmc16-16-module-flush-mounted-metal-enclosure/ https://www.liveelectrical.co.uk/product-detail/fmc16_72 https://www.liveelectrical.co.uk/storage/documents/datasheets/1720044797__LSMC &FMC DATASHEET.pdf

I just gave them a call and got some really useful answers abut the AT350: Learns your usage patterns and does the regen at a suitable time based on that Has a button for manual regen Full regen takes about an hour but they water bypasses (so gives you hard water) for about 20 minutes of that Regen output is at mains pressure Happily used with a 6 person house Low flow rates not likely to be an issue They are local(ish) to me which I like the thought of.

Thanks and you clearly rate them highly then. I have seen NE Water Softeners but they are just about it in terms of choice/competition

Package STP (Solido Smart). I have seen some other systems say they shouldn't receive water softener regeneration waste, but need to check my one. It has already occurred to me that I might be able to bypass the treatment plant with the regeneration drain. My thinking is there shouldn't be anything inherently 'nasty' about the regeneration drain except a high concentration of what has been removed from the hard water. those minerals would have ended up in the STP output anyway so it doesn't seem questionable to put that into the ground.

My current thinking is to soften everything except the kitchen sink and the outside tap.

Be warned, installation is much slower than it would be if all was painted. If all was to be painted then everything could be installed and then painted together. I've had to pre-paint and varnish everything and then carefully install.

Progressing: plan to have sapele shadow gap newel caps as well as the hand and base rails and stair treads. 32mm spindles with 79mm gaps to match what the gaps on the stairs will be.

I've been looking at the various different water softeners on the market and see some of the key features. I consider on demand (metered) regeneration a must, rather than a timer based system. However, I don't really consider a double chamber system a must since a single chamber system with a clock would regenerate in the early hours (about 10 minutes at 2am) and have no real impact. Although we are a family of four, our water usage it limited by planning to 110/person/day, so the demand isn't very high. The Twintec S4 looks to be somewhat of a benchmark and I like the 10 year warranty, but it's not very self build friendly since few suppliers offer it for self installation. Costs about £1200 and only uses blocks so limit supply choices there too. BWT offer a cheaper range and you can pick them up at ScrewFix. Some of the reviews make me a little nervous though, despite a claimed 5 year warranty. The BWT WS555 looks like the best fit for my needs, but I have been put off by the following statement in their installation manual: Does anyone have experience with these units? Are they cheap and cheerful but not a good long term investment? YGWYPF?

Along the landing, we're having Sapele hand rail and base rail with painted spindles in between and painted newel posts. The stair itself is an Open Stringer (or Cut Stringer) design and we're having Sapele treads with painted risers, stringer, spindles and newels. On the stair, the spindles have to be dowel fixed into the treads since there is no stringer top edge to put a base rail on. Every installation I see for spindles along a landing involves the glued packers, a blob of glue top and bottom on the spindles and perhaps some narrow pins through the edge of the base rail and hand rail into the spindles. Does anyone dowel their spindles into the base trail? Would that be excessive? I want to make sure I don't have an unpleasant surprise with the BCO if he says I should have added some fixing to the spindles. https://www.grosvenorstairs.co.uk/product/sapele-low-profile-handrail-44mm-x-60mm/ https://www.grosvenorstairs.co.uk/product/sapele-traditional-baserail-60mm-x-30mm/

Yes it's neat because you can have as many momentary action switches as you like connected to the coil and whichever switch is used, the light will change state.

I like the approach of using latching relays. AnnualCost = (365*24/1000) x Duty x PowerWatts x ElectricityRate = 8.76 x Duty x PowerWatts x ElectricityRate Assuming that for a non-latching relay is PowerWatts = 0.2W, ElectricityRate = £0.20/kWh and the light is on for 3 hours per day (DUTY = 12.5%) that makes AnnualCost = 8.76 x 0.125 x 0.2 x 0.2 = £0.04 Unlikely to justify the latching relay on the basis of saved electricity. GEYA are not a brand I am familiar with, but their website looks like they know what they are doing: https://www.geya.net/ https://geya.store/products/gir-16a-1p-2p-230vac-110vdc-latching-relay?variant=48896365396248 £6.60 each on AliExpress GEYA also make slimline relay sockets for the HongFa 41F relay range: https://www.aliexpress.com/s/wiki-ssr/article/relay-hongfa https://www.geya.net/product/gr-h41f-lz-22mm-slim-relay-socket/ https://www.aliexpress.com/item/1005001437492488.html

Hongfa seem to be reasonable. They are stocked by RS (socket, relay) and Farnell (socket, relay) TEM (socket) https://www.hongfa.com/product/relay-socket/41F-Sockets https://source.hongfa.com//Api/DownloadPdf/201 Aliexpress are just a bit cheaper than most places for them if they aren't knockoffs which is hopefully unlikely. It would be good is LCSC did them A 20way solution with a GPIO buffer would probably run to 2*£30 + £20 = £80 which shows the good value of the Waveshare options not to mention the really cheap ones.

Nice: https://thepihut.com/products/modbus-rtu-32-channel-relay-module https://www.waveshare.com/wiki/Modbus_RTU_Relay_32CH Waveshare are normally pretty good. I can't see any CE mark statement though. Pros: Cheap: £2 / channel -> £3 / channel with RS485 converter and PSU OK ON power: 11.7W / 32 = 366mW / channel Reputable: medium/high though question on CE mark Well supported Cons: It does have significant single points of failure though. I'll always be able to get DIN mounted relays. CE mark? I like Modbus / RS485 and have used it in some fun applications but it's overkill for my setup since they will be co-located. That said, it's a quick solution to the interfacing challenge. Waveshare make some other interesting items: 8-Channel ESP32-S3 WiFi Relay Module with RS485 (PoE Option) £48 30-Channel Ethernet Relay Module with PoE £67 sold out 16-Channel Modbus Ethernet Relay Module £53

They'll have something to remember me by when they are sat in the dark 🤣 Have have wired the house so that it can be converted to a conventional switch based one by only making changes near the consumer unit. That said, it would be good to have the type of relay that has a switch override so that all could be left switched on and then smart bulbs used instead.