Alan Ambrose

>>> There's a procedure to formally request it It'll probably take a week or two for me to get to this. In the meantime, if you search 'wayleaves' and 'dno' or similar here on here, you'll get most of the info.

OK thanks all, much appreciated and thanks for the pointers, links and considerations. Like a lot of subjects, the answer appears to be 'it's complicated' BTW Jeremy's spreadsheet just has floor area x U-value and assumes steady state ground and inside temperature. There's no allowance for perimeter losses and it comes up with a constant heat loss rate over time. So, in an ideal world, I should model the ground conditions, ground water presence & flow, temperature fluctuations at various depths and seasons and the full thermal properties of the basement construction I'm just delving into PHPP modelling and I see they have some resources and calculation methods here: https://passipedia.org/basics/building_physics_-_basics/thermal_bridges/tbcalculation/examples/heatedb https://passipedia.org/basics/building_physics_-_basics/thermal_bridges/tbcalculation/examples/unheatedb But I was hoping for an easy answer.... I'll post back here with any progress I make.

Sadly even some dno staff don’t get 3 phase - at least the ones that deal with consumers. I once had a company send 4 bods on 4 visits over as many months trying to swap out my 3P meter. Eventually they sent the boss and he arrived with a mostly suitable meter.

For a quick read on type of soil, drainage etc you can ask any or all of building control, local builders, the seller, neighbours, septic tank emptying companies, british geological society bore hole records etc etc. All quick and free. Won’t give you a 100% read, but if two or three agree, you’re probably home and dry. A good solicitor will also check utilities and drainage records / easements etc for you.

>>> Some PV guru's could probably enlighten me. Hardly a guru, but each PV panel string usually sits on one central inverter input (or MPPT) and will be limited to the output current of the lowest panel - the panels are literally strung together in series. A string is usually limited up to, say, a dozen panels and is limited to the max inverter input voltage. Total voltage is approx. # panels x 40V. So shading one panel will reduce the output of all the panels to the same extent. With local inverters, there's usually one inverter for each panel (they sit on the roof too) and there's no such limitation. Of course, this option is usually more expensive.

Also, what's the best treatment for unheated spaces like lobbies?

>>> I now specify 3+E and cat6 Run in different conduits?

PHPP form factor apparently is total outside surface area (floor, roof, walls etc) / treated floor area (i.e. sum of internal area of rooms, not including internal walls etc)

As per title - I'm initially looking at Mr Harris' spreadsheet, but also curious about SAP / PHPP treatment? I can see that PHPP talks about unheated vs. heated basements. In practice, I'll probably lay UFH pipes but only use them if we feel the need. For unheated, am I right in thinking that there's an assumption of a constant heat loss through the ground floor just like the non-basement case? Maybe, total basement wall and floor area x constant heat flow per m^2 assuming inside & ground temperatures are fixed? What does that all do to 'form factor' - does it all fall apart in the case of house + basement? I think 'form factor' sort of implicitly assumes that floor, walls & roof have the same temperature gradient?

Mineral wool in the service void as it's more practical to install there than cellulose? Any utility in using posi joists rather than standard rafters so you could run MVHR ducting there? Can I ask how you chose 1.4 as a target u-value? Is that a typical optimum value in practice?

@joth I think the difference of opinion between various sparkys demonstrates that there is no accepted standard / little experience in the field / and not covered in detail by the regs.

Is there no possibility of adding more than 7mm of insulation?

@Iceverge Thanks for the very clear 'heat loss in a nutshell explanation'. Very useful for everyone, I think. Love the colourful fold-up cardboard cutout version of the house design - was that used somewhere, or just to illustrate the surface area? I just bought PHPP yesterday, so @Nic thanks for bringing this subject up at this time

>>> I can't recall the brand It would be fantastic if you could remember which one.

>>> contact the seller/supplier and ask for a VAT invoice. Yeah VAT registered businesses must issue invoices with the VAT clearly shown. You might have an order confirm or whatever instead of an actual invoice. You may have to hassle their accounts department to get it, of course.

>>> BUT there will be a canny waiting time I think they often use this strategy (a) to push cash flow and P&L impact down the track and (b) because a lot of people will need it done quicker and therefore have to ante up for it. There's a procedure to formally request it, I'll remind myself and post it up here is as I have to do this myself. Which DNO? >>> it seems a bit dicey putting them up A technique is to confirm the conversation re minimum distance (not the guy's off-the-cuff remarks of course) in an very polite and professional email and inform them that you are planning to proceed on that basis. Then give it a week or two and press ahead.

>>> I now am thinking I should just go fully for the Passivhaus certification. You don't say why? You can do the calcs yourself if you are happy with uncertified. Or if it's just insulation modelling, Mr Harris' spreadsheet.

Not minerals or car parks?

In these obvious cases, it's seems odd that the LPA don't allow themselves a bit more discretion - they seem to in lots of other areas Does anyone know - is this 'enforcement' action in the planning laws somewhere or is it just accustomed LPA practice.

Yeah agree (a) the simple cheap things like CurrentCost are not very accurate, but they may do, (b) putting in your own accurate in-board meter is a neat alternative, (c) there are also third party per-circuit set-ups with phone apps etc that quite useful (search the forums), (d) accurate 1/2 hour reporting is a benefit of smart meters - I know there are drawbacks but I think it's the future. For instance, you can't access the 'smart' time-of-day tariffs, like Octopus Agile, without one.

>>> some one reported me for starting work with out the full PP. There's always that 'someone' around every plot (: The LPA actually rely on them to police the planning rules.

Well congrats on your potential purchase. We have a barn conversion in East Suffolk and we love it. Some pictures of the structure, plans and the views when you're ready. You might want to add 'location' info to your profile - responses will need to differ depending on where you are and it avoids everyone asking every time where you are building.

>>> He said ideally there should be 1 metre clearance for my type of cables but also said it doesn't really matter & if it was him he'd just put the panels up anyway 😳 Don't you love this? Great that they will be moving your cables foc. Don't hold you breath though - I think it can easily take 2-3 years.

@gravelrash - have you been through the analysis and results to check that the assessor hasn't put in any daft assumptions or made silly errors? It's usually a quick-and-dirty process, and low quality assessors just 'assume' stuff, sometimes wrongly, if it's quicker for them.

Yeah I've moved a couple of accounts to Agile now and re-programmed our usage a bit. We'll see. Ideally we could use some smart-ish logic that, say, chose to heat the building up more overnight when we find that prices are especially low. I can't find time for that atm as I would need to marry up the Agile api plus the Heatmiser api plus maybe a weather api plus a bit of logic. That sounds like a few day's work even with the work that TerryE's has done already.