Lemna gibba

Hi @Super_Paulie, Thanks for commenting. I found your thread quite hard to understand. I think in the short term our set ups are quite similar with mix of rads and UFH in part of the ground floor. I assume that you would still do a buffer if you were installing something similar again. Cheers, Tony

Thanks, I realised that I needed two-port valves. That thread was very useful highlighting the need for a buffer, but I'm not keen on sourcing one from ebay after that saga!

We have a two phase approach to remodelling our house. At the moment we are replacing a conservatory with a single story extension to make a large kitchen area. This will have well insulated floor (150mm PIR) and we are putting UFH in. The room is about 30 m2, it will have two loops but obviously be a single zone. We've had some heat loss calcs done and worked out the pipe spacing and I'm playing in loop cad with designs. The rest of the ground floor will be done in 4-5 years time. Almost certainly add an additional 4 loops. At the moment we will run the UFH from our boiler, but our plan is as soon as we can do phase 2 and insulate the whole house to run the whole thing from an ASHP. We do not want to dig up our newly laid kitchen floor then. It would be way easier to have 2 manifold locations (all be them separated by only 30 cm of wall). One of them for the phase one renovation, and the other for the phase 2. This is because we don't want to lay a porcelain floor then dig part of it up in 4 years. The alternative would be to knock through a part of the wall, install a small beam, buy a 6 -port manifold now, use 2 of the ports but have everything ready for the next phase. The problem is this would come out into our hall. Currently this is (I believe) an uninsulated concrete slab which we will dig out in phase 2. I really don't want to start digging out a section now or try digging around UFH pipes. Can you see a problem with having two manifolds other than price.

Dear all, thank you for your comments. I'm sorry, I wasn't clearer. This is a renovation project not a new build. Furthermore, it is a multi year renovation project. We did get an as built EPC for the renovations we intend to make over the long haul, but won't do a final EPC until the very end. At the moment we're building a single story rear extension and replacing our existing kitchen floor with a well insulated slab. The linked pdf document is very informative. Things like documenting the insulation at the door threshold is not something that I might otherwise have done, but will now.

A big thanks to everyone for their input. I just want to update on our final decision. I came to the conclusion that there was no single right answer. I had several different suggestions that all had benefits. It's impossible to know what the best option was, but I think we have chosen a good one. National Grid got back to us and were happy for us to add the extra solar to single phase as long as we capped export at 4kW. In total we will have 3.2 kW panels on the South roof, 1.5 kW on the East and 1.5 kW on the West. WP also quoted us 1.3k for moving the single phase supply versus 2.8k for installing 3 phase. We've gone for the single phase option.

I'm not sure this is the best forum section for this question, but I couldn't find a better one. I realise that there are many problems with EPC, but I have a straightforward question. We've started building (only digging the footings at the moment). Our house will be better insulated than the current standard. We don't need an EPC at the moment, but I'm sure at some stage we will. I want to make sure I collect enough evidence of the environmental measures that we install. I can see this information online. Acceptable documentary evidence includes, but is not limited to, official letters, certificates, warranties, guarantees. The assessor must be confident, and able to demonstrate, that any documentation relates to the actual property being assessed and that there is no physical evidence to the contrary. Evidence of intent to install does not qualify as acceptable documentary evidence. What does this actually mean in practice? For example, if we install 150 mm of Celotex in the floor. I could keep the uValue calcs from the Celotex product. I could photograph the product going in. I could ask the builder to save the delivery document. I'm very happy with our builder so far on building, but I would say that paperwork isn't his strong point. Would it be appropriate to ask the BC to sign a document at the end confirming that X, Y and Z insulation has been used? Any advice here would be great. I'd rather collect too much evidence than too little.

As an update Catnic have a thermally broken lintel but at the cost of 2k from a builders merchant. This seems beyond our price range. Keystone have suggested this beam XCFS/K-150 , but looking at it I can't really see the advantage of it over the UC with a bottom plate that was originally proposed. Birtley don't have thermally broken lintels that would make a 3.8m span. I understand that the detailing around split lintels is complex, but this remains an option.

@Dillsue and @sharpener Thanks for the comments. I'll let you know as soon as we hear about our request.

I feel that I'm spamming these forums with different questions, but have really appreciated the advice that I've been given. We are building a single story extension. It will be block and brick with a 150mm cavity. We will have large 3.8m sliding doors. The extended part of the room is about 5.9m wide and extended by about 2.4m. In case it's important it will have a 10 degree roof with a 1.2 x 0.8m roof window. We've got triple glazed sliders with a uValue of 0.8. We are trying to be very efficient with this build. We have specified Celotex Thermoclass cavity wall insulation, good insulation in the roof and lots on the concrete slab. Our SE made the calcs ages ago and specified a 152x152x30 UC with 8mm bottom plate. At the time I didn't realise about cold bridging. We're at the stage where we can address this. The rest of the house is mostly solid brick. As we will wrap EWI around this, I'm not concerned about the beams for that part, but I am thinking that having cold bridging above the expensive sliders may well negate the effect of the very expensive triple glazing. I asked our SE about this. We paid him for the calcs ages ago, so he didn't have to come back on this. He suggested that we reached out to a specialist lintel provider. I reached out to Catnic, and they said the catologue price would be nearly 4k! They specified an extra heavy duty one. I'm going to try Keystone next. But at this rate I think this is going to be too expensive. I understand uvalues well, but am having a problem understanding how much of a difference a thermally broken beam would make. If anyone has any input, either on how worthwhile or the best way to get one specified then I would really appreciate this.

@sharpener We need to move the supply anyway. I don't have a price for changing to single phase. But moving the supply and rewiring to 3 phase would be 2.8k (including VAT). I think single phase would be significantly cheaper. Our electricity supply is very illogical. It comes into the East side of our house, goes round the outside of our house at mid height tacked onto the wall and then comes in on the West side with a meter, fuse and consumer unit squeezed above tho door. We would put everything on the east side. If it is just 1ph, then I think they simply need to replace the box on the East and put everything there. 3ph requires coming from the road and us digging the trench. We won't add any more PV (as we don't have space). Heat pump is on the cards in 3-4 years. Our house will hopefully be so efficient by then that a small heat pump would suffice. An EV in the future will be very likely. We have sent the G98 to WP, so we'll see what our options are. I feel that they will insist on 3ph.

That's really clear. We'll go for something small and stylish. We're a half Finnish family so we like our grilled fish. Will check out regenerative filters.

We are designing our kitchen and working out what would be a suitable hood. Our house will have an MHVR system. Therefore, we are looking at recirculating hoods. This will be located above an island and we will have an 80 cm induction hob. All the information that we see regarding sizing of re-circulating hoods doesn't seem to apply for houses with MVHR. The two bits of information that we see are that the physical size of the hood should be wider than the hob. The other is that the capacity of the hood should be 10 times the volume of the room, which in our case would be 750 L/h as we have an open plan area. We think we need to focus on the second rule and the first doesn't match with the hoods we see. Does this seem reasonable? Also we would be very happy if people gave recommendations for hoods that had worked will for them.

Hi, I would appreciate some advice. We extending our kitchen with a NNW facing single story extension. We're looking at putting in a skylight, but are very mindful of overheating. We're thinking about future climates. The extension part will be about 5.7x2.4m. In midsummer the window will be in shade between 11.30-4pm but will get sun outside of these times. Our roof will be very low pitch (ca. 12 degrees). Option 1 would be a Velux low pitch roof window 114 cm wide x 118cm with anti heat shutters. This would be uValue of 1.1 but if we shut the shutters at night then this will improve. we can also shut out the sun if it gets too hot. This is around 2k Option 2 would be a Roof Maker style roof. This wouldn't open, but we're fine with this. I feel with the upstand this might not look so stylish, but again we're ok with this. The uvalues are better and we can get solar control glass However, I cannot see any options for blackout shutters outside. There are several options for blinds inside. And of course there are solar coatings. I feel that the inside blinds won't be as good for blocking heat. At the moment this will replace a conservatory which has much more glazing but gets unbearable in summer. I would much rather be conservative regarding overheating. If you were in a similar position would you go for option 1 or 2?

Many thanks for all the helpful input. I think I've found the information that Dillsue said on page 81 of this document. Just bookmarking it in case it's useful for others. As it seems like the most economical option for us. https://www.ofgem.gov.uk/sites/default/files/2021-12/Feed-in Tariffs_Guidance for renewable installations_V16.pdf For everyone else. We have been in touch with a super helpful company. They have suggested that in our situation the best thing would be to ask WP for permission for 6 Kw on a single phase. If they agree then that will be our best route forward. I'll update with what WP say

That's very interesting. I just had a call with a company who were adamant that if we changed the meter to a three phase then we would lose the FiT payments. I'm wondering if they were thinking along the lines that they don't want to be involved with additional complication and paperwork rather than a set up similar to what you propose. The three phase net metering is the next challenge.