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I likewise thought about an inline heater, but came to the same conclusion. I couldn't see the point in introducing an additional layer of plant when I can deliver what I want from a single ASHP / Cylinder package. We all want to save money and minimise our energy consumption, but I think there are some things where comfort and convenience are more important, and having plenty of hot water on tap, is one of those things. If it costs a little more / I use more energy / I use more water then so be it.

Yes everybody says mains gas but I have a worry that its not a sustainable source of energy, but then what is? Although you can pack one hell of a punch with a gas boiler most people on here build homes that are so well insulated & air tight that the energy requirement for heating is very low to non existent, Domestic Hot Water (DHW) is the main challenge. There is loads here on that challenge (just use DHW in the search box to find out just how much). Last week I was looking at our system and although I had sort of concluded that a combi boiler that could deliver 2 x 10l/min showers was the way to go after @Nickfromwalespointed me at a unit capable of doing it. I am wondering if that might be overkill but it does have the capacity for showers albeit at a cost £ and some small standing losses in the internal preheat system. Although the final system will be an exercise in optimising the compromises you can, in the end, decide much of the detail down the line provided, it seems to me, that you get the basic infrastructure right and make some decision up front. There are also some basic myths to dispel. They are (and I am not sure it helps to understand them): Just because you don't have children and are happy to live the life of a hermit / hippy (nothing against them some of my best friends still are) the people who will purchase your home from you or your estate will pay more for stuff they understand (get). The price of energy is low. True it is now but won't always be. Being self sufficient in energy is a good thing. Not necessarily true because you have to live with your neighbours and they with you so unless you can find a self sufficient solution that relies on no technology you will have to rely on somebody just to keep making the service parts etc. This leads to some upfront decisions - these appear to be: Want to be a) net exporter of energy (SAP > 100), b) use no external energy, sum of external input - generated output = 0 (SAP = 100), c) use some external energy (SAP <100) If you go for options a) then you will inevitably need some sort of energy storage system to smooth out the generation curves you are likely to get unless you have access to something like Hydro generation and even then... We have : Natural Gas, E7 or E10 but will need to change supplier, Sun - so could have PV or ST We don't have: Provision for wind (not enough space), Hydro - no flowing water to speak of, We won't have: GSHP -small area available but costs very high, Oil & LPG So far on my list of 'infrastructure' I have: Ducts to get ASHP services into the the building and to the plant room (at this stage I don't intend to install an ASHP) but given the cost of small piece of ducting.... Ducts to get additional PV, for garden mounted PV cells, into the building and to the plant room. Ducts, or just routes, to get Roof mounted PV services to the plant room. Enough room, and wall pattressing (extra strength in the walls), in the plant room for the; MVHR, a Thermal Store (TS) or UnVented Cylinder (UVC) or a phase transfer storage system, a boiler, a couple of heat exchangers, 3 - 4 pumps and associated valves, pipework & wiring. Space somewhere for the control panel (in our case not in the plant room but in the downstairs WC where one wall is spare! - there are reasons.) UFH - which we technically don't need, Passive House Planning Package (PHPP) says warm air will be enough, but it unlocks a whole mass of possibilities for heating, cooling and moving heat about. See the @JSHarris blogs for more on that. I will not terminate the UFH other than to pressurise it for testing and during the slab pour. I think the cost of installing it will be around £400 but I, or my descendants, will get this back from the people who buy it safe in the knowledge that it has UFH available - not many people understand hot air although a lot of people generate it. Provision for in duct cooling and heating around (or in if you can afford one with it built in again see @JSHarris) the MVHR box. Can be fed from boiler, or ASHP if installed or could be electric heating (cooling not simple with electricity alone) Masses of insulation around the plant room to help with any standing losses, effectively isolating it from the house so what happens in the plant room stays in the plant room. I would like to eliminate standing losses if I can, I am sure I read somewhere here that @SteamyTea got to a point where his DHW energy use was the same as the standing losses so 50% of energy is notionally going to waste but probably heats the house in winter but is a problem in the summer. Using the MVHR to extract warm air from the plant room and redistributing it make sense but the cost of generating it in the first place needs to be considered - IMO I have also provisioned for a battery store adjacent to the garden room and can use the existing electric ducting to carry the connections back to the house and generation points. Have kept waste water separate from the raw sewage down to the plant room in case I feel the need to deploy waste water heat recovery via a simple heat exchanger. (Added 21/11/2016 when reminded) Some things imply other things so: if you go for ST then you probably will need at Thermal Store and a UVC won't work. If you have ASHP you will need supplementary systems to make DHW and you will probably need Underfloor heating and a buffer tank to optimise the ASHP output. It is unlikely that you will install both a TS and a UVC In short its probably one of the most difficult choices out there if you have a conscience and want to do the best thing for your finances and the planet. Hope this helps - could write a book by combining the people on here but I am not sure you would arrive at a consensus unless its to agree that there is no one right answer.

Today was one of those 'b*gger b*gger b*gger' days. Offered up the various bits of wood, sill, etc, to the window to work out how I was going to do the reveal detailing, and it turns out my sills are not deep enough. Nobody's fault but mine- at some point in the build I had switched from using 25mm cladding battens to 50mm, and this has eaten up the overhang. If I press ahead, the sills will just, barely, clear the edge of the cladding, with around 10mm overhang. I think I have three options: 1- Buy new, deeper, sills- obviously the most expensive option. They are Aluron profiles, roughly how much would these be per metre? 2- Re-install the windows (must be a computer joke in there somewhere). I am quite reluctant to do that knowing how long it took me to put them first time around. I could probably do the job in two or three days but it's a psychology thing- would feel like I was taking backwards steps. Moving them 25mm towards the outside of the wall would be enough to restore the overhang and would make the faces match the counterbattens, which could simplify some of the detailing. 3- Alter my cladding design. I have vertical board-on-board 20mm larch planks, nailed to horizontal 50x50 battens which in turn are screwed to vertical 25x50 counter battens. If I change the horizontal battens to 25x50 that solves the problem (it was the original design) but will it make the cladding too prone to flexing? I don't really want the wall to bend when you lean on it! How much would it help if I doubled the number of battens (easy) or halved the centres by installing more counterbattens (less easy, and these would not be nailed onto studs, just the 11mm sheathing). Any other options? I'll just have to console myself that this is probably the silliest mistake I have made so far, which is not bad going given I have designed, drawn, and built this house completely singlehanded so far...

I missed the bit about the attic versus insulating the floor. If funds allow I would insulate the roof as all that insulation will be wasted if you then convert the space above it and you'll have to spend the money all over again insulating the roof. I guess you will still get some benefit if you don't heat the roof space as often as the rest of the house. Particularly if you plan to convert the loft reasonably soon, then insulating the first floor to 0.1 is overkill. It will cost more to insulate the actual roof as the area is larger but that will save you a lot in the long run. Also there will be no VAT assuming it is a new build versus a loft conversion. Also are there light fittings and pipework in the ceiling? This will make it awkward to get a good fit with PIR.

I had a crack at something like this on an old shed.....with CANS. Did the walls and floor: The floor: One of the STUPIDEST things I've ever done by far.

The Nibe we had in our last house had that ability. As you say, I think it's pretty standard function. The difficulty we found with storing DHW at a lower temperature than traditional systems, is that you run out when using the shower because of the differential required for the thermostatic valve to work. We had IIRC 210 litre capacity but this was only just enough for two showers. However, whilst there may not have been enough DHW for showers, there would still always be plenty of water left over 38C but under 48C available for sinks / basins. To get round this, we have opted to go with a 300 litre cylinder. We don't intend heating DHW to more than 50C using our ASHP. I'm more than confident that the heat pump will be able to cope with this, albeit at a slighty reduced COP. Having number crunched, I don't think there is much (if anything) cost wise if we were to go the other route and simply preheat with a heat pump and top up with immersion / inline heater as a matter of routine. We will have a fortnightly legionella cycle via immersion top up.

I have the 25mm cross battens behind my cladding and there is no flex at all. They are solid! In fact I remember someone querying your 50mm battens so put a good shoulder against mine at the weekend. Chose a bit where I knew I was between horizontal battens and it's rock solid. As the Welsh wizard says...worry ye not

Yes that is what I meant but its only mixing down with the return flow from the UFH and the other high grade losses will only be in the pipework between the heat source and the UFH mixer valve. However your point about high grade heat, what is your definition of high grade I wonder, and mixing is a good one and perhaps we (I) need to think about it in energy terms more directly. My thinking was that the boiler would only deliver what was required, modulate down and stay within its efficiency range, once the hot tank was filled. Trouble is, when you expect that, the efficient modulation range of the boiler (or other heat source) I think the smallest boiler goes down to about 3Kw which I suspect is much more than you would need to put into an already warm slab which is surrounded by an airtight and well insulated structure. Your other point about getting the floor temp down is a very good one that needs thinking about, as you say I also seem to recall JSH struggling with that one as well but I have not followed it up. Is the limit set by the mixer valve I wonder. Off I go to read the JSH stuff again.

Yep, my reply was directed at this comment from Mike, which as I interpret it suggests the possibility of mixing high temp water to a lower temperature for use in UFH: My bog standard Panasonic controller allows different temps to be set for heating and DHW modes. I seem to recall Jeremy's offered that option as well. Worth checking with the manufacturer you're using (or thinking of using), but certainly it doesn't appear to be an uncommon feature.

How can you tell? Was she wearing a crown? Dressed like Freddie Mercury?

Homeowner 1 Wasps 0 Seems like there's no activity now, cold snap and wasp powder should have done for them. Spent the afternoon laying the first lot of insulation which has made a massive difference already.

This is possible because the UFH will (can) mix return water from the UFH with hot water from boiler to control slab temperature the full hot water can go off round the hot water tank.

As an aside, I believe Panasonic manufactures more air-conditioning & heat pump compressors than any other company in the world. I don't know how that translates into completed units - I assume they manufacture for others as well. But the general point is spot on: heat pumps are one of the best understood pieces of tech around. It's the same tech that's in every consumer fridge and aircon unit, and they are, in general, incredibly reliable. The important thing is to make sure that it isn't being asked to do more (or too much less) than it's designed for. In general, the bad reports from air source heat pumps installations have been in leaky, poorly insulated buildings where they just weren't the right answer. Build it insulated and airtight, and ASHPs are fine. You also need to think about whether your heating and hot water will be supplied by the same system.

Gimp, I wasted two and a half years fighting planning, wasted £1000 on a planning consultant who was rubbish. Don't be afraid to take it to appeal if you get refused. I wanted to build two story and the council wanted a bungalow or room in roof. The appeal process is not rocket science, in fact I was advised that if you use simplistic terms ( not too technical) then you stand a good chance. I hoped to win but with some small concessions but in fact I won on ALL points and had no concessions. The inspector even used some of my own words in her judgement. The inspector told the LPA that my build did fit with their policies ( suggesting that they did not interpret their own policies correctly). I did my appeal myself and cost me nothing but a little effort. Tip, the LPA are not allowed to dictate style!, my argument was that a "bungalow" is a style. I ended up with four planning applications trying to appease the LPA. But you are allowed two goes for one fee. Go for it. I can send you a link to the applications and the appeal if you want. J

And you will need an FCU, isolation switch and waterproof cover for that LED. If you keep the Loo Rolls in the fridge, the internet-fridge can autotell Tesco to send some more.

What size of house? To get under £100K is doing well, I doubt I will achieve that in spite of me doing so much of the work myself. As Peter says, No 1 is insulate, insulate, insulate. No 2 is air tightness. No 3 is good doors and windows, No 4 is an MVHR unit (mechanical ventilation with heat recovery) Then you can think about heating, which should not be much. I am going for an air source heat pump and to buy one for self install should be under £1500, possibly under £1000, i.e not a great deal more than an ordinary boiler. I personally would not have oil or LPG again, the price is too volatile. (though I will have LPG for cooking, the usage is so low that the cost hardly matters) I will be fitting solar PV, but by the time I get there, I doubt the (already low) feed in tariff will exist any more. So that means a DIY installed system bought as cheap as possible, and almost certainly some form of battery storage to ensure near 100% self usage. Tell us more about your house design and where you are building. Oh and welcome to the forum.

None ..... Invest in the the fabric of the building and make it far exceed the regs on insulation and air tightness and you shouldn't need heating. UFH coils in the floor can be done for less than £100 at build time and no need to add the manifold unless you need to. If you go conventional and have gas available then it's seen as the default cheapest, but @SteamyTea has some good info on direct electric heating

SSD if 2.5" will probably need an adapter to go in an HDD bay in the tower. I've bought loads of cheap drive enclosures etc from P C World. For some reason they're dirt cheap: http://www.pcworld.co.uk/gbuk/computing-accessories/office-supplies/pc-care-and-cleaning/dynamode-2-5-3-5-bracket-mounting-kit-07929915-pdt.html I tend to put the OS on the SSD and storage on the HDD. Gives a new lease of life to an old pc. Put a Linux distro on it and you're flying!