Alan Ambrose

By which I mean large overcapacity of panels. Object being to provide almost all power in the summer & shoulder seasons - only using imported power in the winter?

OK a bit more info: + the Zehnder unit has the benefit of not being 'handed' (as it's switchable) but the drawback is that it's quite a lot physically taller - 850mm vs. 650mm. + the Brink unit seems to be consistently £600 more expensive than the Zehnder. + the Brink Vigor / Flair etc brand confusion doesn't inspire confidence. Which organisation will be supporting? Neither was my experience of their duct system which seem half-baked ... just like someone on their design team had never ever tried to install it. + both Brink & Zehnder seem to need an extra bit of electronics for web control. Although, in the end the built-in RS485 / Modbus might be the best control solution. According to Google AI (which I have not verified) the Brink units need an actual internet connection for the app to work, the Zehnder units don't. While the bigger physical size is a pain, I'm leaning towards the Zehnder unit.

Don't know whether you got @saveasteading 's point: If you hire in machines, hire surveyors or other 'knowledge workers', buy tools etc then you can't claim back the VAT - these are examples of things that are not on the self-build VAT-reclaim list. If a trade does this for you in the course of doing some work involving labour then they can claim back the VAT but their supply will still be zero-rated to you. That is, you've saved the VAT over buying directly. The other factor though I think is this - it takes a fair amount of time and effort to hunt for good prices / compare products etc. Most trades won't bother knowing they're just going to bill straight through anyway. You have a much bigger incentive to keep your own bill down.

p.s. the lowest point of any cable overhanging the entrance + the ground level underneath for any tall vehicle height checks. Plus the location of any known external services for service design e.g. where is the nearest Openreach pole with fibre on it, ditto power, water.

@john0wingnut >>> how I am going to run an intumescent strip along the top with ventilation mesh Envirograf do a combined mesh / intumescent product if that helps.

>>> So do I need the windows as well as the ridge and eaves for No 3? Sorry missed that. Can’t see any reason to unless you think you might have a battle over ‘overlooking’ or need to establish some similarity to the neighbours e.g. building a new end-of-terrace. In any case once the surveyors have done their set-up, marked their stations, taken gps coords of those, recorded points say on a 2m grid for ground levels, features, fences, poles, pipes etc etc etc … a few extra points will (should) make zilch difference to the price. You may want to use the same surveyors to mark out your design, so you might ask them about that process. Also, you might like to set-up a hard-to-disturb datum level (we used scaffold poles) at a known round number absolute level. Then you can calc other levels from that with a laser whenever you need.

@Owain1602 >>> What are you going to do at the heads of the windows? We used thin stainless strip as per an earlier ‘ub discussion. Quite a bit of work, but done now. Much cheaper than intumescent of course and seems to me anything fireproof will work (maybe not in the regs though) as you don’t need the expandability of intumescent.

>>> I raised the subject of "automatic fire suppression". Would be interested to hear about that. FYI, just spoke to Envirograf - they asked what the BCO said and actually agreed with him ... but said that for belt-and-braces a strip under the eaves and gables and at the bottom of the cladding was good. Also the windows etc. But then they are selling the stuff. 😀 p.s. Envirograf said there was a v good illustration on the NHBC website. Envirograf couldn't / wouldn't send me a link or copy. And I can't find it. Think I'm going with a strip at the top of the cladding only. >>> External cavity measures are borderline irrelevant for a regular domestic dwelling of 1 or 2 stories, in my own opinion. Might depend on how generally flammable the build is, but kind of agree - esp. as we're one storey and all rooms except bathrooms have a door to the outside.

Replace with copper? Probably not so hard.

Congrats - I can't think that contingent agreements are easy to negotiate. Any chance of having to go to appeal? Re which step, it may depend on whether you think your LPA will want to engage in a time consuming horse trade. Also, whether you'll be happy with just outline.

Suggest both / Yes / Yes / Just centre & verge . You probably won't need the 3D but 3D dwgs are a thing and shouldn't add more cost as the total station'll be recording in 3D anyway. Invert levels are essential for planning drainage. Also, invert levels for any ditches etc you plan to drain to. Should cost v little. V useful for discussions re appropriate ridge height. Just the neighbours will be fine. Should cost v little. Probably just centre and verge for defining sight lines for access. Unless your access is tricky and there are things in the way.

>>> As for positioning, I’d agree that they will be less effective at ground level, but I’d also argue that one wouldn’t want a single strip atop a 6m cladding ‘chimney’. That's an interesting point. For a highish single storey like we have (our eaves are at ~3.5m) maybe it would make sense to have it, say, 2/3rds up. If it's right at the top, the fire has to get all the way up before it operates.

Think 0.5mm steel rather than 0.8mm. @G and J & @Owain1602 Can I ask - did you do intumescent strip at the bottom of the cladding cavity? @Owain1602 - interested on why you didn't do the gables - did it not have the same circumstances as the eaves? BTW this is what my BCO said on this subject: Fire stopping cavity barriers are not enforceable under building regulations for individual domestic dwellings. Only enforceable in buildings with separate compartment ie flats or semi’s. Although I do think the fire stopping strip is a good idea it is your choice in this circumstance.

So, for the OP @Beelbeebub that suggests 2-core 4mm PV ultra SWA (PV-ULTRA2C4.0SWA) rated at 52A and £9 p.m. Power loss at 15A is 15^2 * 5 (ohms per km) * 2 conductors i.e. about 220W per 100m (and you're carrying ~4kW at that point, so 6%). Voltage loss 15 x 5 / 10 * 2 = 15V i.e. ~4% (per 100m again). Not insignificant. >>> And is there a problem with exporting the earth? Good question.

Agreed and the temp co-efficient might push that up to 50V at low temperatures.

>>> maybe 8+ panels for each house So maybe 400V max (at low temperatures) & 15A max (in summer sun).

I've been mulling this situation over too. I don't think it's that uncommon with e.g. (a) panels on a roof, (b) modern all-in-one stacks which tend to have all the bits (inverter, battery, gateway, car charger etc) all at the same location. And as batteries can't be an an attic these days, it suggests the stack is outside or in an outbuilding and maybe some distance away from the panels - which implies a longish DC connection. Either that, or the inverter is in the attic and the battery some distance away, which implies likely an ac connection, but then a split stack.

Following @G and J comments, I've been researching this again. It's not completely obvious - NHBC doesn't go into a lot of detail re timber cladding & cavities, nor the building regs. They say a bit but a picture or two would have been nice. My current thinking is that 0.5mm steel is fine around windows & doors but intumescent might be required at the top of the cavity. I've not figured out the bottom yet.

Think the question is whether it's standard cat5 wiring. Probably is, but the cut off end would prove it. Is that still in the dish? Or if the other end is a length of cable too, then it’s not a big problem as long as you use the same convention on both ends, and you can use, say, the joiner above.

Understanding Starlink Cable Requirements.Does Starlink Use Cat 5 Cable? | XUNJIE CABLE What Kind of Cable Does Starlink Use? CAT6 vs CAT5e Explained

Easiest/cheapest would be a nerdy teenager who has terminated CAT5 cable before 😀.

If it is CAT5/6, you need something like these: https://www.amazon.co.uk/dp/B088R5F3D2 (Get the 'pass through' ones rather than the standard ones, much easier to use.) Note that you need slightly different ones for CAT6 as the conductors are slightly thicker. https://www.amazon.co.uk/dp/B0CH3TDJ4B https://www.amazon.co.uk/dp/B08CZW1CQ8 These are also cool for joining CAT5 cables and supposed to be water / weather proof. https://www.amazon.co.uk/dp/B09YHQQ91S

I think it would be easier to concentrate on the physical problem and seeing if it could be solved easily. For reference, we have ‘temporary’ taps around the site and atm the water feels surprisingly hot for a few seconds when turned on. It’s just a few metres of pipe getting heated up by the sun. Plant rooms often get quite hot because of all the gear in there. Suggest buy yourself a few metres of the grey snap on insulation for a couple of quid, fit it neatly to all the cold supply pipes you can see and see if that helps. Does this happen all the year round or only in the summer?

You need a proper crimp tool, and preferably a tester and a bit of a knack for small fiddly things. Easier to check out the other end, check it’s a standard LAN cable (Google?) and replace the whole thing. Can recommend the right bits though if you want to try yourself. Loads of videos on youtube on how to crimp cat5/6. It’s a useful skill.