G and J

You sweet talking thing you! Lol OK, what .035 product are you thinking of?

Both bed 1 windows face east. I called them north and south to differentiate them, i.e. the more northerly of the two and the more southerly. I can see (now) that being confusing. Sorry. I do appreciate you taking a look at this you know. Yep, bed 1 is a furnace (according to part O anyway). I’ve played with the details of the opening window and that’s I think the greatest ventilation I can get with that window size. If there are other settings that are better I’d be chuffed to bits. The oriel window is fixed to avoid extra balcony glass/ironwork/whatever and to get the maximum glazed area to enjoy the view over the in bed morning coffee (it’s a wrinkly thing). To convert this and a couple of others to opening would probably cost a lot more than paying a consultant to do me dynamic part Oh! and still not pass the simplified method. I did that on my first pass. Makes things worse. Maybe I should try it again in case I mislead myself (one of my key skills, it appears!). I could not fathom what these numbers were for. So I took it to mean sequential window numbers in each room. Might redo these. Thing is I have tried all sorts with this and I can’t get a pass on simplified method. That’s even with me claiming cross ventilation which is a bit of a stretch. That’s why I resigned myself to a choice of wholesale glazing design changes or a dynamic modelling method, and the glazing choice would not make me happy and will cost more. I wonder if our BCO has looked at our design and said to himself, ‘that’s ok from an overheating point of view’ and that adds to the argument that a PHPP report will be enough evidence.

(I know I should start a new thread but I can’t resist replying….) That'll take our wall u value from 0.181 to 0.184 and I think I’m pushing my luck at 0.181 as it is…. but I will price it up.

So, here it is, my latest attempt (of several) to get this b$£**!!ing spreadsheet to reflect common sense. I'd be chuffed if anyone can identify where I'm going wrong and thus can avoid a dynamic modelling thingy. 20241207 Simplified Part 0 - munged.xlsx

We are planning 140mm stud frame, filled with 140mm Nyrock 032, thence 60mm battens with 60mm Rockwool RW3 inboard of the frame. Downstairs will have rendered block skin too, upstairs will have 15mm plasterboard so we hope we will be ok on the noise front. Fingers crossed, but it's a relatively quiet area. (Woodbridge, where all the wrinklies go to serve their final years, all encouraged by the Guardian's best places to live list it seems!)

Hmmm, can you simply isolate the battery systems to see if the behaviour persists? And have you a clamp (he writes as if he understands exactly how they work!)

Well done for gathering that data. What else does your system include? I don’t know enough about it to recognise the boxes in your pic.

I’d be watching for a gradual change in voltages between the two dc feeds as the sun goes round. Ok today may be a bit hopeless but still, if you catch it with zero on one feed screenshot it, it’s hard data that will be useful for diagnostics.

Is that right now? If so it appears to be showing both sides doing a bit as you’d expect this close to noon, if your ridge is more or less running due north to south.

It does seem to suggest an intermittent issue with the west solar wiring. Have you an app for the inverter? If you do can you see input voltages?

The spreadsheet uses a clock face type designation for the direct each window is facing and then in a separate box you set which direction the clock face is orientated to. In our case that bit is easy, our drawing are draw with due north damn near directly upwards. The big one has an oriel and is fixed to avoid needing a balustrade and the small one does fully open. Will do, we’ve been messing with it to try and understand how it works and so I’m going to redo it from scratch first. I’d be chuffed to bits with some help here, so thank you.

Good point. I’m looking at an MVHR unit that’s spec’d for about twice our size, though that was done in pursuit of quietness and longevity but clearly it would also help if we did overheat. Because we’ve had a good few hot nights here in Suffolk over the last few years we are going for an ASHP that also cools, with a deployed Fancoil in the main bedroom and probably plumbing and wiring for fancoils in the other bedrooms too. We’ll run one zone for UFH and Fancoil to start with and run just above dew point, with the option of ‘valving’ out the Fancoil if needed so we can run really cold without condensed floors. So I’m feeling ok about overheating in reality. Part O is however different. Plan is to use 90mm semi rigid (I think it’s the zhender stuff) in a radial system and I’m doubling up vents in a couple of areas. I’m hoping to hit less than 0.5 but in truth it’s the thing I’m least confidant of and in the next couple of months I need to learn more towards this. We have a narrow plot and thus thin walls and my initial disappointment with that has given way to a feeling that airtight makes up for a lot of missing U. We shall see but one lives in hope. I appreciate the input @Nickfromwales

We have always had Clearview, but their designs are more suited to traditional, so we are planning a Charnwood in our new place, not this stove but the build quality of Charnwood is good........ Chk on the photos that new rope has been fitted behind the door and inside looks good (ideally new fire bricks) Last thing is your fitter happy to fit a stove he's not supplying?

A lifetime mortgage is for us wrinklies. No monthly repayments, interest charges roll up and it’s only repaid when the property is sold on death of the last surviving mortgagee (or them going into care). A fab way of funding growing old disgracefully if one doesn’t care how much of a financial legacy one leaves behind.

That’s very kind of you to say. Behind that little row of houses is a quiet little area of back gardens which I’m hoping will prove a lovely place to be whilst still being in easy walking distance of more cafés than one can shake a loyalty card at. We've engaged a company called Vantage. They were recommended by our architect and I have spoken to a couple of the inspectors and they seem good, practical guys to work with. They’re currently looking at our plans so we’ll see what comes back.

After reading your stuff about it we did try doing the future homes spreadsheet. Now we are doing it very strictly and we could not get the results thing all ok. We do have some fixed windows, and from memory one of the issues is that the patio doors aren’t in a huge room, so proportionally it appears on the spreadsheet to be too much. However, I’m now scratching my stubble and thinking, ‘ok, maybe I’ll try this again’….

If you are staying at the house for a good few years fit a Clearview Pioneer, expensive but brilliant. I've owned 3. It's small enough to not need a vent, and it will reduce wood usage massively. The payback will be a couple of years but you'll be up and down to load the fire a lot less.

Quick thoughts.....what does your local planning guidance have to say on the subject of infill or within/without village envelope/boundaries.....where does your house fall? Also does your planning authority have a "cluster policy"? Maybe unpalatable but I've seen situations such as this where a small development of houses is allowed around an existing house with one larger plot to be retained for a singleton property. Some friends did this but it was a long haul to get through.......

I think the actual overheating issue is exclusively me, under the collar, when I contemplate the box ticking exercise that really is a sledgehammer nutcracker. We are aiming at nicely airtight as we will have MVHR, but our insulation levels are modest (for a number of reasons more or less building regs in fact). Our design has limited amounts of glazing, but it does have a 4m wide patio door at the back. We can’t use the simplified method, as we can’t claim blow through and the patio doors blow it for one room. So we are required to do the dynamic method to prove the bleedin obvious, but rules is rules. Here are the elevations. In glazing terms it’s not exactly Crystal Palace is it?

Did you get your doorbell sorted? If not, I saw this and thought of you….

We’ve just submitted our design for building regs approval. Our BCO has agreed that we can use PHPP to demonstrate that our design won’t overheat and thus is ok with part O. I think PHPP 10 is the latest and will cost me somewhere between £200 and £250. Is this what I need to purchase? Or do I need other bits too?

Option 3, treble MVHR extract vents over stinky bit? Option 4, cook stinky stuff in utility room, (trendily renamed ‘spice kitchen’) and open the window…. I'm building in option 5, cook stinky stuff in spice kitchen (see above) and have a closable inlet and extract just for that room.

Re Lewis decking and screed upstairs, I really, really hope that’s not needed as I’ve not designed anything like that in. Most peeps manage with just posijoists and caberboard methinks. But then, there’s just the three of us (one little dog, one grown up, and me) so maybe the requirements are less onerous.

Ta. I had that option and was nervous about bounce so I’m designing in a sleeper wall so our max span is 3.7m.

@Iceverge is your preference for EPS over PIR primarily due to environmental or other considerations?