WestcountryWonderer

Yes, I think this is correct. I think the systems have to have a bit of thought put into them to avoid this. On the other hand as you say, PV either gets used for other loads once the cylinder is hot, or worst case just goes back into the grid

I would tend to agree with you (in my also limeted knowledge) in it's basic form, solar thermal is a pump and a valve and an expansion vessle and two heat exchangers - on the roof and the cyliner. aside from the pump and valve (which is no different than the central heating systems we all have), nothing else moves. Happy to be corrected here. My only thought is that PV has no moving parts at all, and the systems whilest containing complicated electronics, are failry well developed to be reliable. In my mind it comes down to which is more efficiant, and most cost effective.

Yes That is my understanding. And again, I'd do an in roof install as we're re-roofing at the same time so the panels wouldn't protrude past the existing roofline. However we do have some listed buildings nearby (although ours isn't) And the planning officer I was speaking to did make a comment about adding them into updated drawings (as we're looking to make a non-material ammendment elsewhere) but I never managed to get him to clarify his comment as I don't really want to back myself into having them by putting them on the drawings when there are a lot of factors that could affect fitting them - money/DNO approval etc etc. Any way. A bit of a tangent there!

Thanks for the comments. Additional PV is the other option I have so that might be the better route. I have 6.5kWp (on a 3 phase supply so still within the 3.6kWp per phase) split 50:50 on east/west facing roofs. I can potentially get some more panels on a south facing roof when we do the extension. Just debating if the council planning will have anything to say if the PV (or ST) goes on at the same time as doing the extension works. I'll go and trawl through the PV part of the forum next then!

I'm looking into fitting solar thermal when we build our extension. I already have PV which I am in the process of diverting to the immersion heater but also considering batteries so wondering if solar thermal as well would be a good boost to the hot water and allow the morning PV to put some charge back into the battery again. I remeber finding a supplier who was recomended for teh DIY world, good quality kit but happy to deal with you and me as well as trades which a lot of the big auppliers aren't so helpful if youre not trade. Does anyone recomend anywhere for supply but also for information about the set up etc? Looking to get an upderstanding for how the system is installed as well before I commit to a definate yes. I'm looking for in roof panels so presumably flat panels if that makes any difference to recomendations?

Good afternoon. I'm part way though getting planning permission for a new garage, things are looking a little more hopefull now so I'm back to thinking about the details again... I'm planning to build using Nudura ICF and could do with some thoughts/words of wisdom about the garage door threashold details. This is a large garage (9.5m x 7m) so will come under building regs,. It's not heated, just insulated to keep it reasonably comfortable for a garage/workshop for myself. So far I'm planning to use Geocell recycled glass for the subbase as that will give insulation and a solid base in one product. And then I'm less likely to worry about how stable EPS or smilar would be for under a garage floor (I'm building to allow fitting a two post lift eventually). On top of that is going to be a 100mm concrete slab, then build the ICF walls to form the perimeter, then once the walls ect are finished, a second 100mm deep concrete slab over the top of the first. The reason being the first will give a solid surface to fix the ICF supports to but then I want a nice smooth powerfloated finish for the garage floor without any holes in it that need filling. A litte over-engineered perhaps but unless there is any glaring issues people can see with it, I want the best finish that I can achieve. Originally I was thinking of using the Nudura under the garage door threashold, up to the top of the first 100mm slab, then when the second slab goes in, having that flow through the door opening to create the threshold, with a 30-40mm step in it so the door closes onto the lower part to help it seal and keep out any driven rain. I could reinforce the step with a bit of steal angle (galve, painted etc) if needed. I started wondering about how best to finishe the DMP. Should I just run it out through the door and finish it at the edge of the slab, or should it be finished some other way? Another option would be to use curb stones along the front of the slab to help reinforce it against wheels 'tearing' at the edge and also act in a slightly saecreficial way. Or are there any better ideas?? Part of the reason for using the nudura under the door opening was to reduce any thermal bridging, I know the room isnt heated, but I figured that every little helps. Is it really much of a big deal? Am I better just having the concrete slab going down to the foundation level and so making the threshold stronger still? I'm planning an insulated sectional garage door from Securoglide, to be fitted in the reveals rather than on the inside face of the walls. On a side note, the geocell glass supplier recomend using a geotextile under for the DMP, but in my mind that wont keep damp out, so surely that should be a proper DMP sheeting? I've attached a couple of PDFs that hopefully help with my explanation. Any thoughts or comments would be most helpfull. Many thanks!! GARAGE DOOR DETAIL.pdf TYPICAL WALL & FLOOR DETAIL.pdf

Sorry I wasn't very clear with the background to this - it was the previous owners who got the planning permission and for some reason they/whoever did the survey for the drawings appearently did not lift the lid of the manhole. When I get a minute to do that, it should be prety clear as everything is within aabout 1m or less of said manhole. What I'm wondering is if building control will allow existing rainwater connections to the sewer main to remain as that when the extension work is completed, or will with insist that all rainwater is diverted to the soakaway. If the current drain situation isn't clear when I open up the manhole and/or building control are likely to allow combined rainwater and sererage to remain, they yes, a camera survey will ineed be worth it.

We only bought the place at the beginning of the year and the drainage survey only showed a combined sewer, plus its a small rural village and a lot of the houses are 100s of years old rather than 10s. So I very much doubt there'd be a separate sewer hiding somewhere. The square meterage is there and the ground drains well enough for a soakaway that will cope with the whole roof, it's just going to be a bit convoluted to get there from the front

Not withstanding the old addage about assumptions... My extension planning drawings show that the current soil stack, kitchen waste pipe and rainwater pipe are "assumed to be combined and connected to the sewer" or words to that effect. Most likely they are assuming that the combining is done under the manhole cover that's next to them all (why they made the assumption and didnt just lift the lid up is beyond me, but that's getting off topic!) If this assumption turns out to be true, would building control likely allow them to remain combined albeing probably with a new inspection chamber? or would they insist that the rainwater gets diverted to a soakaway? We already have a soakaway shown in the back garden for the rear roof and at a push it would be possible to divert the front roof to that, but it would be a bit of a pain that would be nice to avoid if I can. Not to mention convoluted and long which opens up more chance of blockages vs a nice short run of around 1m... Am I also right in thinking that if they are combined, they must do the actual combining in an inspection chamber and not tee'd into the soil stack itself at a low (under ground) level? Both instances having a trap at the bottom of the rain water pipe.

That is a very comprehensive list, and is what I was aiming to achieve with my last house (renovation not build) but I got a bit lost along the way. A couple of thoughts though. To save running telephone wire and cat cables, telephone can utilise the cat cables. The down side to that is cat5/6 is slightly more expensive than telephone wire. Up side being that one cable can do either/or job. Long hdmi cables are OK, but if you're burying cables and/or running them any great distance you'd be better off looking at hdmi over cat. Again, it increases the cost slightly, but the reliability and quality will be better. You can do similar for audio too.

I'd run as many cables as you can. At this stage it's easier to put more in than it is later down the line. If you can, and you think that you'll have a lot of them, pick a central location to run all of your CAT cables to and put a hub/switch there. Ideally near where the phone line comes in to out the router there as well. Also think about tvs etc all being able to connect to the internet now a days. In an ideal world, anything that is in a fixed location should be hard wired to the Internet. The less you have on WiFi, the better it will perform for things that have to be on it. Are you likely to have cctv? If not now, in the future? They'll want cat cables too. For terrestrial TV signals you can do the same, pick a central location and use a splitter to send the signal to anywhere and everywhere you want to. Sky gets a little more tricky as I believe that you can only have a limited number of tvs per sky box (I've never had it though so could be corrected on that!) As for cable segregation, as far as possible is always best, but 100mm should be ample. The reality is that in 'normal' domestic conditions you're unlikely to notice much of a difference even if you ran signal and power side by side.

The next question that has sprung to mind on this topic is that I have a rain water outlet that is noted as 'assumed' to be connected to a combined sewer via a manhole (there is a soil stack running next to it.) I suspect that the reality is that the rain water pipe just goes into a hole in the ground rather than anywhere meaningfull. Am I right to assume that I wouldn't get away with reinstating this and actually running it into the combined sewer if it isn't already? What about it it turns out that it does currently go into the sewer, can I reinstate it to the sewer then? And I guess that I am also right to assume that if I move the rain water outlet from the front roof which currently discharges into the road (and therefore eventually the sewer) to the other end of the house, then this will also not be allowed to discharge into the combined sewer? And must go to the new soakaway?

That is interesting about insurance and not something I had really thought that much about. Although it might be me being a little neigheve but my house insurance doesn't cover any item over 2k unless it's been listed anyway. so I'm not sure what the difference would be. the house insurance is due soon so I'll give them a call to see what they have to say

I hadn't thought about that if I'm honest, but part of the reason for thinking about SIPS is that I seem to remember a national homebuilding webinar wherre the SIPS manufacturer went to great lengths to ephesise that they are classified as 'traditional building method' for insurance etc. i.e. they have certificates etc etc and not just someone has got a pile of timber and nailed it together. I hadn't considered ICF but I will look into it. Especially as I've just seen a social media post from the architecht who's coming to look next week that she has just done a training day with an ICF supplier... This is also where I'm thnking that plasterboard and skimed walls and ceiling are the only option internally. With any joints sealed with firee proof silicone. Thanks for that, what size timbers did you use there? and were the trusses manufacturerd or did you make them on site? I want to keep the roof as low as possible to help with not upsetting neighbours and not blocking out too much sun from my garden. But it's good to hear that someone has done a 7m span as that was one area I wondered if I'd come unstuck in. The main reasons for avoiding block and brick is the time it will take for me to build it. Lots of food for though from here though so thank you, exactly what I was after with this post!

Thanks. That looks very nice! I'm aiming for 2.5m clearance through the door (my Land rover is just over 2.3 high so need that and little spare for comfort!). Trusses are possibly an option for mine, but not sure if I'd spend more money getting them calculated and made than I would just stick building or going for SIPS which would be easier to keep the clearance. The insulation for me is partly having to comply with BR but also partly trying to keep a fairly stable temp summer and winter while also keeping the dampnesss out to stop things rusting! aread wise I could get in under PD as the garden would be big enough. But the height would prevent that I think and the proximity to the boundary definately prevents it. I cant afford to move it further off the bournary as that will be too restrictive so planning permission is the only option. Hence having an architecht take a look