cjsparkey

First off it’s definitely something you can do yourself just needs a bit of organisation. Our big mistake was not being good at recording invoices regularly enough, if I was doing this again I’d record invoices weekly onto a spreadsheet as it was we spent 3 full days going through invoices, emailed invoices and online checkouts to get everything together. Then make sure you have full VAT invoices, we found loads that were statements or receipts and had to go back and get VAT invoices, again if we had done this weekly it would have been easier. Otherwise the HMRC system works well, it’s easy to start the application online, I did call them with some queries a number of times and the people I spoke to were very helpful.

Just thought I’d share our experience of our DIY VAT claim with HMRC We achieved BC sign off at the end of September 25 but had moved in 9 months prior. 11/12/25 submitted online application spreadsheet with all invoices up to the date of submission 16/12/25 received request for 10 invoices 17/12/25 uploaded requested invoices 12/1/26 received notification of payout with one disputed invoice noted 19/1/26 sent clarification off disputed invoice (I had mistakenly uploaded a pro forma invoice instead of the full VAT invoice so corrected this) 20/1/26 received initial payment 9/2/26 received outstanding payment for the disputed invoice completing the claim For us the HMRC system seemed to work pretty well.

MCB/RCD/RCBO To DP isolator for Eddi, load side of the Eddi to immersion via a local isolator. Technically the local isolator for the immersion might not be needed if the Eddi is local to the immersion but it’s handy if you ever need to isolate the immersion without needing to shut down the Eddi.

The steel wire is for mechanical protection, if you can route the DC cables so this isn’t needed that’s an option or copex etc wherever it needs mechanical protection.

+1 Terminate the PV cables into a DC isolator, go for a branded isolator and oversize 32A rather than 16/20A the larger enclosures make terminating easier with 6mm cables.

This would be my thought as well, if you are running 230v around a construction site it really needs to be swa to fixed socket outlets with a couple of 5kva transformers plugged in or hard wired to a 10kva transformer.

For your own peace of mind something non-combustible, galvanised metal cable tray works well as it can allow a air gap all round and makes for easy mounting and cable management.

What a fantastic and existing project, we’re in D&G and have just achieved BC sign off on our new build this month. Happy to share what knowledge we have and local contacts if needed.

Are you installing with MCS certification? If you are self installing outside of MCS then it’s not guaranteed you will get any return on the energy you export, so it makes any restriction less of an issue.

From that graph it looks like since 2010ish the year on year increase in the levels has slowed.if not levelled out compared to the previous decades? looks like something is happening?

Those last two posts are far too sensible, it won’t catch on in todays polarised society where you are encouraged to take sides and nuance has left the discourse. The wind turbine developments locally to us have integrated storage and solar to maximise the efficiency and presumably return on investment.

Could you install a duct with draw rope then pull the cable in at a later date once you have your sparky sorted.

Our build is similar mix of vaulted ceiling in the living areas and 2.4m ceilings in the bedrooms, bathrooms, utility etc. with loft space over all under warm roof. We chose to put insulation in the ceilings really just for extra sound proofing, the loft spaces are pretty much the same temperature as the rest of the house.

If you are thinking of going with Fogstar battery they have a list of hybrid inverters that are compatible with on their website. Plug-and-Play Inverter Compatibility: The PACE Battery Management System (BMS) seamlessly integrates with a wide range of popular inverters, including (but not limited to) Victron, Pylontech, Growatt, Sofar, Solis, and Goodwe

How many units make up the island? Could you swap the dishwasher along?

Useful to know We had to go full G99 (G100) as 6.8Kw and limited export to 3.6Kw due to feeble rural power network. Back to the question @CMPW which bit of the notification is causing the query?

Not familiar with UKPN G98 form but up here in Scotland the SPN notification form is quite minimal, if you have the MCS cert most if not all the information should be there. Technically the DNO is supposed to be informed before switching on but it’s usually straight forward.

Personal preference but even with fire rated led downlights I fit hoods or form a plasterboard box to keep the insulation from being in direct contact with the fitting, allowing some air space around the fitting. Manufacturers usually specify a minimum free airspace around the fitting, this can be as little as 30mm on some but worth checking. Some fittings can be supplied with optional insulation guards to stop the installation coming into direct contact with the fitting.

Maybe not that then, only mentioning that as we had a similar issue with a leisure battery in our Campervan, it would self heat every night as the temperature dropped if we were not using it.

Do the batteries have some form of internal heating function? Could this cause the discharge?

I did post a query in the Tomato energy thread but thought I ought to put this here rather than throw that thread off topic. In our self built bungalow we already have installed 6.8kw PV and a solis hybrid inverter, all self installed but delayed installation of the battery storage until the detached garage got finished. I’m a retired electrician, although I may have to go back to work once the build is finished😉 so can tackle most jobs. I have been looking at the Fogstar selpos kits and wanted to know from users whether they worked out a good option? There are other options ITS Technologies, thanks @Bramco again it would be good to hear from users.

Apologies for jumping in on this thread, I'm just looking at ordering either one of the fogstar kits or a prebuilt unit and wondering how challenging you found the build up of the kit?

Just commissioning our self installed MVHR and found this thread helpful. Hope it helps.

It’s not fully clear from that first picture but it looks like a 30mA RCD, are you on a TT earth rod ? Normal practice would be for this to be a 100mA or even 300mA unit to provide some discrimination as it is primarily protecting the circuit as far as the internal DB.

We signed up a while back and finally found a quiet evening to post a hello. We are well into our self build in southwest Scotland, I’m a sparkle by trade so have been around building sites all my working life, we are currently a third of the way through nailing 7500 slates on the roof in an attempt to get watertight. Just like to say I’ve found this forum a great source of inspiration and information.