JamesPa

Ok so I'm thinking it's possible that you can't comply with the planners requirements without blocking your driveway. Screen on neighbours side of your driveway probably too high, screen on your side of driveway too close to ashp, screen in middle of driveway just right but not practical. Accoustic enclosure doesn't actually meet the condition you have quoted because it has air gaps. Am I right? If so your choices are Go for an accoustic enclosure (you will want to get quotes and be sitting down when you read them) and seek a variation to the condition Relocate and seek a variation to the consent Make it so it confirms to pd rules You need to decide which of these before taking it further. Is the consent granted already or is it just that the planners have told you what they will require once consent is granted

Three questions Where is the neighbours window? Is the driveway yours? How high is the ashp?

That's pretty much a specification for a fence/wall/barrier not an enclosure, which is good. So you just need to design something at least as far away as the min distance specified in the ashp spec. Distance will determine height and maybe width. Density and chosen material will determine thickness. I did a quick density calculation, it's thicker than a fence but not as solid as a brick wall if you make it from wood. Obviously something loaded, like the barrier mat @JohnMosuggests, can be thinner because it's denser. Plan of the area and the full text of the condition would be good. Ps if the barrier is more than han 2m high it might require planning consent!

You are doing well with your planners. My ashp location (if I had one) is 6m from the neighbours window and it's fully screened, still not good enough. They want me to get to 25dBA at neighbours window (which is essentially impossible). Council run by Green party. Acoustic enclosures currently mighty expensive (like 2-4k). What might you 'get away' with? Maybe a wooden screen (more solid than a fence) or wall?

The pipes connected to the ashp itself should be flexible to stop transmission of vibration. If they are (I can't tell - might be worth checking) then his arrangement keeps the joints to the fixed pipework behind the ashp. That's a good visual decision.

I wouldn't have a problem with this and it seems to me that local authorities could cope provided the system was self-funding. There would have to be a disclaimer on the licence that the local authority doesn't guarantee standards, and a fee to cover both the admin cost and the cost of enforcement, so that it is self funding. Much better IMHO that this is done by a local authority than a private company like MCS. Of coures it begs the question of why the existing bodies of which most traders are members wont suffice (NAPIT, GasSafe etc) as suggested by @SteamyTea The other avenue is building regulations. MCS standards, if they are required at all (which, for the most part IMHO, they are not) should be folded into building regs. Again this is an established system and building inspectors are well used to checking the work of others as intelligent interrogators not necessarily experts in their own right. The combination of these two would be a winner as far as I am concerned. It allows plumbers and electricians back into the renewables market, gets rid of the monopoly, and leverages existing infrastructure. As an aside I have been told that MCS exists largely because of the need to have 'standards' associated with government grants. Im not sure if that is the case or not. None of this would stop the cowboys and nothing will. But proper competition from local traders, combined with enforcement through existing channels, will make them less likely to get business. Currently that is frustrated by the monopoly position in renewables held by MCS

100%. Unless the existing heating it resistance electric, selling an ASHP on the basis that it will save money is mis-selling. Roughly the same is reasonably honest (the exact numbers of course depend on the ratio of oil/gas to electric price, which fluctuates, and the quality of the installation).

This is, IMHO, never going to happen in the UK, particularly 'This license should be revocable if standards are not met, preventing repeat offenders from continuing to operate'. The costs and complexity of administering such a scheme are too great for our government, whatever the shade, to contemplate and we don't (and wont) have the skilled inspectors to 'police' it. Also regulation stifles innovation, which we desperately need in the retrofit market (which is the market that needs to be addressed a) because retrofits make up the majority of our housing and b) because retrofits are to houses which, unlike newbuilds, emit most carbon). Currently we have a half way house, where the industry is essentially a closed shop (MCS), but there is little or no enforcement. That's the worst of all worlds. The alternative is to open it up properly to competition by abolishing the closed shop thus making it possible for local plumbers and electricians, who value their reputation to compete. Personally I would advocate that as a practical solution. Its not perfect but its way better than the current 'worst of all worlds', in practice almost unregulated, monopoly.

That was the original plan. However it's visually unattractive because it means two sets of panels of radically different appearance will be adjacent (my existing panels look quite different from the panels you get today). I'm honestly not convinced there is a solution and wishing I'd maxed the panels from day1. Back then however over-panelling wasn't so well recognised as a valid technique and panels themselves were a significant part of the cost.

Currently I have String 1 2500Wp nominal. 15deg elevation sw facing (10*250W) String 2 1500Wp nominal 45 Deg elevation sw facing. (6*250W) Although thats 4kW peak nominal the low elevation of string 1 and SW aspect means its about 3.2 kW peak actual. However the declared installed capacity doesn't take this into account so the declared capacity is the lesser of 3.68 and 4 ie 3.68. There are various options on how to connect inverter(s) but they all revolve around the same or a very similar upgrade to the panels. The obvious upgrade physically is to leave string 2 alone and increase string 1 to 8*400W =3200Wp. The inverter (SB4000) can cope according to SunnyDesigner. 3 of the recovered panels can be reused to make a separate, standalone 750W array on the cheapest inverter I can find and the remaining 3 set aside for future use or spares should any of the old panels fail. Possibly a couple of panels in the new string 2 array could be connected to this inverter instead of the original one to reduce the extent to which it is over-panneled. It's difficult to calculate exactly how much energy is lost from the over-panelling because clipping is of course based on the instantaneous output. But my best estimate is that it's around 10% of the increase. It's not worth taking the design further until I can find someone who will do it. So far the solar installers in the area have only shown interest in starting again from scratch, at which point it's not worthwhile. I think the market might have cooled somewhat from when I did the research eighteen months ago, so I might just have better luck now. Will look into roofers too but, I'm still struggling to believe they will touch a system that has 400V DC on it.

My reading of the rules is that, because the existing system is being modified (and the new generation goes through the same generation meter), I need MCS certification of the system as modified. The fit payments are then made based on the generation meter reading adjusted by the ratio of (MCS certified) generation capacity. If this isn't the case are you saying the rules allow me to self certify the new generation capacity for the fit calculation. That seems improbable.

I think MCS is needed unfortunately because output goes through existing inverter and thus existing generation meter. Afaik this needs MCS to certify the capacity change on change of system. This itself is interesting, the capacity is defined as the peak and since it is now and will be inverter limited, apparently the capacity as defined is unchanged, even though the total generated amount will. However because the system has changed MCS still needs to certify it. At least that's how I read the regs on modifying s fit eligible system (unless they have changed in the last 12 mo). Also the panels are daisy chained into the inverter so are plugged together on the roof. I'm surprised a roofer would touch 400V DC.

I have been wondering about that. Will roofers do this sort of thing as a standalone job. Strictly also it needs MCS to retain the fit payment (about 45p per generated unit). The generation will go up quite a bit so the fact it's been done is detectable

In principle yes. Actually it's not in principle even necessary to change the inverter, because it can handle the new DC input. A bit of clipping at peak hours in peak months but nothing worth worrying about until the inverter needs renewing anyway. Now try finding anyone to quote for that in the south east of England! The issue again is not the technology, it's the marketplace.

Thanks. I think that's already done as I'm on metered export not deemed (possibly a mistake given my recent acquisition of an electric car), and my bills seem to have several mpans already.

No, but it is the sort of thing that the Daily Mail might claim, or for that matter several other equally regressive media outlets some of which purport to be serious journals. Sofaik heat pumps are the only realistic mass market solution for domestic heating, so we don't have a choice, whatever it costs is certainly less than the cost of our of control global climate chaos. Quite what the proprietors of these outlets think they are achieving now escapes me. I guess it's to postpone the inevitable action, this making the consequences even more terrible, but that doesn't matter because they, and their slimy friends, are all super rich so will emigrate to New Zealand, turn it into a right wing state to keep everyone else out and exploit the now desperate population of much of the rest of the world to service an increasingly isolated but nevertheless luxurious lifestyle. It's totally unconscionable.

Thanks I looked at the guidance, there are a lot of options! Practically speaking I have a generation meter and a smets2 smart meter. I think the latter does net metering so I think that covers it for most of the likely configurations. I would check with my supplier first anyway (Octopus), always assuming I can eventually get a sensible quote!

That sounds interesting. I am struggling to find a cost effective way to expand and/or add batteries to my 4kWp array fitted in 2011. Without a doubt it's possible, but finding a way to isolate an add on that someone is interested in quoting for is proving challenging, most want to rip it all out and start again. Have you by any chance got a circuit/bloch diagram of your set up?

Ok, if this is the case then only protection (logically) required is to guarantee that the tank never reaches 100C. With a heat pump it's impossible so we only need to bother about any immersion/resistance electric heater. So in a retrofit ashp replacing a gas boiler move the immersion out of the cylinder to somewhere there is both a convenient drain and heating pipework (eg where the condensing boiler used to be!) fit a thermostatic valve to divert any water reaching 95 somewhere other than the cylinder (in addition to the various electrical protections), job done. No need logically for D1, D2 malarky at the cylinder itself, and no new pipework needed. Lots of disruption and money saved. Not compliant with the guidance but compliant with the actual regulation so far as I can see.

Totally agree, although 'anyone who can follow printed instructions.' would seem to exclude many in the construction/plumbing industry judging by what we hear on this forum. To my mind its a classic 'job for the boys'. As you know I'm equally frustrated by the rigidity and sheer lack of innovation with which G3 is interpreted. @JohnMo will doubtless tell me to stop flogging a dead horse at this point, but its yet another factor holding back ASHPs.

Oh dear. It looks like my idea of cutting out the tile and plasterboard behind with a multitool (preserving the tile) might not work, because the tile in question extends above the likely position of the window board. It still might be worth trying however, once you have cut round three sides and cut through the grout between the with the button and the horizontal one above it, the tile with the button may ease away. It rather depends on how well the tiler glued it down and how the substrate is interfaced at the corner. Some care would need to be taken to avoid chipping the horizontal time. You still stand a fighting change IMHO, but it could also go wrong (resulting in a broken tile). If you do succeed in getting the tile off (with the substrate on which it is mounted) in one piece this way then it will be fairly easy to clean it up and refit it. If you have just one spare tile then, even if you do break the existing tile, you can refit and nobody will know. be careful not to saw through the cistern though - ie control the depth of the cut.

I agree in practice, although others argue that there is a bit of leeway because the law actually says 'MCS Planning Standards or equivalent standards', and then contend that they can themselves install to 'equivalent standards'. I would counter argue that there is no recognised equivalent standard and so, if it came to a challenge (which is the only time it matters), you would need to convince your LPA of your interpretation, which they would be disinclined to believe. Given that all development is unlawful unless its expressly lawful, that puts you on the back foot and you would need to contest your case with the planning inspectorate or ultimately through the courts (in the latter case with MCS likely being called as an 'expert witness'), whilst risking enforcement action the effect of which is to disable your heating. This is hardly an attractive prospect. So if you do want to claim 'equivalence' then you would be well advised IMHO to seek, prior to installation, a certificate of lawful development (specifying the methods to be used so its clear you wont be using MCS). If its rejected you can then appeal to the planning inspector and make your 'equivalence' case before you commit. Of course if you are a long way from neighbours much of planning law can, in practice, be safely ignored, on the grounds that nobody is likely to complain and thus the LPA wont bother taking action. As @johnmo says monoblocs are pre-filled and do not require f-gas or gas safe qualifications. They are different, most plumbers have gas-safe but relatively few have f-gas which tends to reside in the aircon industry. Splits do generally require f-gas. I have not seen this condition applied to a planning consent (and I have looked at a fair few decision notices). I'm not sure it would even be lawful to do so because building regulations are, so far as I am aware, not a material consideration in planning which is (or is intended to be) solely concerned about the public impact of development. Planning decision notices may remind you of the need to comply with regulations other than Planning law, but that's not a condition just a helpful reminder of a requirement which applies anyway. However compliance with building regulations is always mandatory anyway (albeit that the regs themselves have many get-out clauses) If you have express planning consent then you don't need MCS (unless the LPA has made that a condition of the consent, which is unlikely). You must always comply with building regulations when you do any building work, but only some activities are notifiable (ie require you actually to tell BC). The ones I am aware of which are relevant to an ASHP installation are the installation of a new electrical circuit and the installation of a UVC. Both of these must (in England), so far as I am aware, be notified to building control unless they are carried out by a tradesman that is a member of an approved registered body. MCS is not an approved body for either of these, but almost any plumber/electrician will be a member of an approved body. Yes. If you have express planning consent then you can cheerfully self install without any further ado, either notifying BC about the UVC and/or new circuit (they may or may not care) or getting pretty much any plumber to do or sign off the UVC, and any electrician to do or sign off the circuit installation. It you apply for consent for a new build or major extension, and it happens to include an ASHP, then LPAs seem quite frequently to concentrate on the bigger picture not the minutiae of the ASHP itself. You are thus quite likely to get consent which includes the ASHP and you are good to go. Many on this forum have done exactly that. However if the development is solely the retrofit of an ASHP to an existing building, then you either have to go PD = MCS or you have to ask for express consent for the ASHP alone, which of course focusses the LPA attention. Depending on your LPA you may be faced either with an impossible task (eg mine) or they may wave it through with little fuss/constraint (eg @sharpener). If you do get express consent then what it says about new builds applies. In either case if you don't use MCS you don't get the grant. Otherwise its a turd. The hope on the horizon is flexiorb, which is developing standards alternative to the MCS ones. They have started with solar panels, but say they intend to go onto ASHPs. Its currently unclear to me whether they will gain much traction or be any more sane, although that appears to be their aspiration.

How idiotic. Sadly I've seen this done before in a refurbished public toilet of all places, and I'm not in any way associated with the building trade. If it's plasterboard behind the tiling, could you use a multi-tool to cut simultaneously through the grout of the tile the button is in and the plasterboard behind? I think that would my go-to approach. If it's something more solid than plasterboard behind perhaps consider taking the tile out anyway and replacing it with a symmetrically positioned access panel (be 'honest' with it rather than trying to disguise it).

The law is the law. Government 'guidance' is often an imprecise approximation (during COVID it was sometimes just plain wrong!). In this case building control and planning, which are two totally separate branches of law dealing with different aspects of development, are being wrongly conflated. Its best to keep a clear head and separate them. So to unpick this "Thanks, IIRC the Planning Portal says that any ASHP installation can fall under Permitted Development if the installation complies with MCS 020 and part of this standard requires that the installation must be carried out by an MCS approved installer" 'Can' is not the same as 'does' The actual law on permitted development (in England), which is definitive, is here. See specifically Schedule 2 part 14G. There are quite a few requirements beyond MCS-020. "Without a PD exemption, normal planning and building control applies. " Without a PD exemption, normal planning applies, however building control is a separate and parallel branch of legislation to planning. It applies whether or not the development is done under PD. Building Control doesn't say a lot about ASHPs but what it does say is totally independent of the planning regime under which the development takes place. Building Control rules do, however, depend on whether it is a retrofit or part of a new building/major refit/change of use. "This is all a lot simpler if the installation is done as part of the initial build and part of this planning and building control approval, but in our case that was over 6 years ago." Yes, because in this case the Local Planning Authority (LPA )focusses on the bigger picture not the minutiae of the ASHP! The Building Control regulations in this case are, however, much tighter, but in most cases easier to achieve because you are not constrained by what is already there. "As a post sign-off install, this control itself introduces a shed load of bureaucracy and costs. In the case where the proposed ASHP is to the rear and within the property curtilage, you would need to demonstrate to BControl that the installation complies with gas-safe, positioning and noise regs." No. Gas safe regs are irrelevant because there is no gas. Building control doesn't care about positioning and noise regs, that's a matter for planning. " In this last case it would be practically impossible to get BC sign-off of your calcs unless the ASHP unit is an MCS approved model." If its done as a retrofit BC has very little say about efficiency or anything else of relevance to swapping fossil fuel heating for ASHP (other than G3). BC doesn't care about MCS, its not even mentioned in the BC rules. If its a newbuild then BC does have quite a lot to say about efficiency, but it says nothing about MCS or any of the MCS rules that appear to be troubling you..

I was wondering that as well. If they did 4kW, which is my actual normal load for most of the heating season it would be very tempting indeed!