Andeh

What research did you do into ASHP and it's applicability to you? How did you come across the need for one? Are you on mains gas? DHW is an instant odd one, ours currently heats ours to 50degs, and can do nearly 55 degrees. Yours should be able to do the same. Do you have UFH? Did you over size the radiators? Your heat loss is pretty average for a newish buildin the last 10/20 years and isn't the worst I've seen, but it won't be cheaper to run then other sources of heating... I wouldn't expect it to be ruinous to run though. How warm do you like the house? Also, what's your actual usage of the ASHP? "powering external units" clouds the information you're providing.

Sorry OP, that's a pretty basic thing to have gotten wrong! You need to weigh up the cost to rectify back to what you had permission for vs time, money and effort vs fighting it. Probably win in the long term if you can show what you've built is in keeping with existing design principles in your immediate area. Porch may be tricky if it's in front of a building line or equiv. How much bigger did you make it? I'd probably look at finding a local planning consultant in your immediate area to advise on the potential of a successful appeal, and pull something together! I could imagine being on the back foot for

Heatmiser, it's a good one but we have over zoned it..... But nothing plaster and paint can't fix if it does prove to be an issue... Which for now it isn't!

Does everything have a U bend? Your picture implies they all do? If virtually no fall, and regular use with soap etc it will gunk up. I presume you have a very shallow distance to enable a proper fall to be installed? Could surface mount a proper soil pipe and box in? Create a low shelf, tile it in etc

We used 25 to 50mm PIR with expanding foam to fill in the gaps!

I would be wary of one potential awkward tenant ruining it for all. One tenant having a full, hot bath in the morning or evening.... would deplete a large portion of that 300L. And/or several hot showers in the morning or evening emptying it again. Broadband... A couple of people downloading torrents etc can have an impact if everyone else is watching Netflix or gaming. That hot water situation would be a concern though, as could be a massive headache as people will NOT be quiet about semi regular cold showers which they can't control, predict or plan around.

Don't forget the context before you fall out of love for your house. Buildhub is here for the extreme high end of the market, so your scores are not great to this forums standards, but that's still a better score then 90% of homes on the market, and all the savings you mentioned might save you £15-20 month. Top up loft insulation, and some additional detailing around the edges will get you an extra a few% few average UK home. I imagine your heating bills anyway won't be much more then £150 a month?

Could they Rockwool behind, timber battern in, fire rated expanding foam sealing it all in tight, then plasterboard over the top?

As has been said, use this storm to inspect how damp the walls get. Generally you get it rendered down to 2 engineered blocks, which is where DPC is. I'd be tempted to use this storm and the damp near ground level to get the render trimmed back up. Not a great pic, but you can see where my dpc as the render stops, I have raised beds/driveway etc to go in yet!

I think you'll struggle with something so rigid. Rockwool will at least scrunch up and can be torn up and stuffed in!

Have you got any pics of before installation? Or during construction?

"When I asked him did he fit a cavity closer he asked me to define what I meant as he hasn’t heard of them. Builder for 40 years ‍" That really boils my blood, (expletive deleted)ing builders and their shitty attitude and fly by night nature. It would have been negligible cost and effort for him to use them. If it makes you feel any better we had a window fitter who was incompetent, lazy with a shit attitude to boot. Carpenters ended up finishing the window installation and fixing his faults, and they did a brilliant job in comparison.

I would probably drill a couple of 10mm holes and poke borescope through, taking pics. That will PROBABLY reveal a slump in Insulation. Buy a multi tool and cut a couple/few of 12 x 12inch sized holes (trying to avoid any wood supports/batterns) to enable me to push rockwook strips in, and using a pole push it either side of the few hole cut. Cut one hole and experiment to see how many holes you need to push rockwool. Patch holes by gluing/screwing recessedwood batterns across, then glueing/screwing plasterboard back into place. Fill, sand, fill, sand paint. If it looks poor, go with corkboard on top. Then sit back smugly over your success, and enjoy the return on investment in 50 years time!

Is it water running down the render and dripping, or is it soaking into the render and running down within it?

If in doubt.... More clout! (and beef up the insulation elsewhere, where you can... Roof? External? Draft proofing?)

Sorry, my bad spelling!! Borescope / inspection camera. However, what you'll probably find will be several inches of gap along the top insulation wise, so again consider where you cut the hole (central?) so that it gives you good access to resolve. One big access hole is easier to repair then several small ones. This sort of thing.... Inspection Camera USB Endoscope,7.9 mm Borescope Inspection Snake Camera IP67 Waterproof, Semi-Rigid Cord with 6 LED Lights,Tube Sink Pipe Drain Camera for Android, iPhone, iPad(9.84FT) https://amzn.eu/d/71FhiP2

Or drill a very small hole for a horoscope! They are pretty cheap and will do the job.

Honestly, the time cost and stress will out weigh the slump in insulation you'll find. Once all is said and done, whatever improvements you make will take 10 years to pay off.... Probably more. If you are hell bent on it, it a good sized central hole, so that when you find a gap in the insulation you can fix it via the same hole. Reality is.... You'll never notice the difference before and after. Ignorance. Is. Bliss.

Are the pipes all warm to the touch leaving and entering the manifold? Is there any temp difference between flow and return? Buy an IR thermometer for £10 and check each rooms.

Still difficult to gauge your finish, can you take some wider angle pics? This is south facing, so not as much driving wind, but I have pressure washed it all a few times, incl channels, and that does force water in.. But it sits in the channels a bit, but not enough to need more then a kitchen roll wipe up.... External grout is a bit rough, but we haven't snagged yet...!

Yeah, it came up in discussion with the architect when I was bemoaning some additional costs walked in by our structural engineer (who always felt expensively over zealous in everything he insisted we did....!!). Our architect brought up the fact she saw builder install heave protection (or clayboard? could have been something along those lines....) per building control and/or structural engineer and our builder was lightly grumpy about it as overkill,...and architect explained that everyone was having to take a few hits on the chin with the 'contract price' build the Builder had given us (and stuck to pretty well tbf) and also us taking on a few hits on prices walked in by third parties. Would clayboard or heave protection be 100mm thick insulation like sheets? Grey or white? or something?

Every now & then you get lucky & you find the nugget of gold you needed that will enable you to step back from throwing yourself off the room....... Short version is, the garage/bungalow was cut down into the ground by 3-4 feet due to the nature of us building on a hillside & the willow + garden being further up the hill from our build. This means the foundations were c1.8m deep....but they already started from a depth of 3-4 feet lower then the natural ground anyway....thus foundations being c2.5m below willow ground level! ------------------------------ Dear Building Control, As discussed this morning, we would like confirmation please that you are satisfied with the foundations of the new garage with the proximity/slight incursions into the willow roots. The arboriculturalist has confirmed this is okay from a tree perspective. Please find attached the arboricultural survey, engineering drawings and part of the architectural package including substructure, floor plans and elevations. Note that the design has changed from 140sqm extension to complete knockdown/rebuild and we are pending the updated engineering drawings for the rebuild element, although the extended element footprint remains the same and the replacement build element footprint is very similar. If there’s any further information which would help please let me know. Many thanks, Architect Good Afternoon Architect, The foundation depths do not correspond with Chapter 4.2 of the NHBC Standards and look to shallow. Have they been verified by a structural engineer? Kind Regards Building Control Hi Building Control, The structural engineer confirms that the footings are already at the right level as the garage is cut into the ground leaving the footings approximately 2.5 metres below ground level at the Willow. He will add some contours to the drawing to make that clearer. The arboriculturist confirms that he didn’t recommend a root barrier in his report. If the engineers have recommended something then they will have a spec. He’s not aware that a root barrier is necessary unless the soil is known to be shrinkable, but again this is something for the structural engineer to decide when they are specifying foundations. Best regards, Architect ****Sharing of several more drawings, contours & foundation levels*** Morning Architect, Thank you for the drawing showing the contours. I can confirm that I am happy with the foundation design. Did the Planners at West Northamptonshire Council set this as a condition? If so, they will need to be sent this info to clear the condition. Kind Regards Building Control

That's interesting to see & difficult to know what to do with that info! I've pinged the photos & suggestions on foundation details off to our architects to seek their views & confirmation on foundations in this area. The foundations could have been that deep, but its difficult to remember other then remembering 'I couldn't see out of the trench'.

Can only trust the experts here on the depth of foundations, we had tree surveys specific for this willow tree, root assessments, structural engineer spec'd it then the builder was razer sharp in preparing them. We are about 1m outside of the root ball following the assessments, and it is only for a single story, cavity double garage end of the day! I can't find the dimensions, but I remember stood nervously in it & not seeing over the top and im 6ft!

There were surprisingly few roots we came across actually. I remember as I actually cut a few stragglers back (tiny several mm type ones). I was slightly nervous doing it, as the builder had warned me about deep foundations & wet weather when we were visiting the site over the Christmas period (My wife was supervising as my emergency help!!). The heave protection might have been something else though, the architect told me she saw them being installing heave protection after building control had demanded it, and I never asked anything more about it. What gives me comfort is not a single person visited the site & didn't comment on the ridiculousness of the foundations, the running joke was we built the foundations for the skyscraper we were going to convert the bungalow into afterwards. Thanks for your thoughts so far though!