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Indy

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Everything posted by Indy

  1. I looked into this and seems an impressive product and would get rid of a lot of the hassle with regards to getting builders to do the right thing. I've had a quote from them - looks like they do it solely based on floorspace and it's coming in at just a shade over £3k ex VAT! Seems like a pretty high number and I'm sure there are cheaper ways to achieve the airtightness?
  2. Can I ask for an opinion on the option to go for a Lewis deck on the 1st floor ? This would be covered with a thin layer of screed which gives the floor a little more solidity, acoustic insulation (which I want to prevent noise transferring across floors) and a little better fire prevention capabilities. This was something the architect and I had discussed a long time ago and agreed but due to the whole process dragging on far longer than anticipated - was mostly missed in the pack I have so far. The SE design will need to be redone, the 1st floor height has been done at 2422 to account for normal floors and 22mm UFH system, whereas Lewis deck would mean I need to give up an extra 27mm of headheight as the system with UFH will come in at 52mm vs the 25mm of the existing option. Has anyone does this and does it really work? This is the one we're considering LEWIS-Metal-decking-brochure-2022-EN-web.pdf
  3. Thank you @Iceverge - that's a really terrific input and lots of food for thought. I will admit I don't know what the difference is between yours and the one I posted originally apart from the areas where there's greater insulation and wall depth, and therefore assuming U-Values must be better. I take your point about buildability and cost as well. The tough part will be how do I get this all incorporated in my BR drawings as it could mean redoing a lot of the work that has already been done and I'm really at a point where I want to finalise the pack and start tendering the work out!
  4. No, there is a room behind it which is my study and this gives extra headroom and there's a skylight in that room on that flat dormer. Because I hate creaking stairs in our current house and the original thought was to build an ICF house with concrete stairs, walls and floors. Moved away from this due to cost reasons but decided to keep the concrete stairs requirement. This would go well with the Lewis deck and screed floors that I'm planning for the 1st floor. Have the option of either though - and my initial quote of a pre-cast staircase wasn't as horrible as I was expecting. £4k including delivery but it would need cladding and installation etc. Getting quotes for timber stairs ranges from £3-4k for pine to about £10-12k for hardwood oak stairs - so the differential isn't as large as I was expecting, though this is all desktop research for now. We'll finalise which route to go when we get firmer prices back on either option and the SE designs/calcs we have cater for both.
  5. Same for us - it's really there for wow factor more than actual utility. It will come on for about a week between Christmas and New year (based on the usage of our current gas fire) when we have friends and family over for entertaining and showing off. Not really meant to be the primary or even secondary heating system.
  6. I am keen on having an airtight house though we're working towards a target of 3.5 at the design stage. It's something I will discuss with the main contractor and stress on as the build goes on. However, we do like to open the windows from time to time and the sliding doors are pretty non negotiable I have to say. Wood burner is something I like (as do both the boys) so I guess it will stay but I've been told you can get chimney stacks that aid airtightness when not being used?
  7. What alternatives should I look at? Somewhat by design - given that BR is already a huge step up. I'm not too keen on losing internal space and we're limited on how far out we can go as we need to leave a 1m gap on either side of the property from the fence line. I have to admit I will need to spend time understanding all of this - though I assume VCL is a Vapour Control Layer?
  8. I have heard the same re cost of wet plaster vs dot and dab being the same from a contractor I spoke to - just a little more work for the plasterer. However, my architect is convinced this was more expensive and would increase the drying time by several months - which would mean we couldn't paint the property or to expect cracking for at least 6m afterwards. So we changed tack to parge coat and dot and dab as a compromise.
  9. Yes, wet UFH currently planned on both floors.
  10. Taken your advice - separate thread started here
  11. Following the recommendation on another thread, putting up the details of my build here to ask for recommendations on things can be improved. We're not aiming for a Passivhaus level of spec, as the law of diminishing returns means that the payback probably is not worth it. Aiming for a Building Regs compliant comfortable family home - and this is going to be a massive step up from a 1930s semi with no cavity wall (where we currently live). Ground floor is Beam and Block, and First floor is 225mm posi joist, Lewis deck with screed (for more stability). 2 sets of sliding doors (4.1m wide each) at the back which is West facing. Putting in ASHP, MVHR, in roof Solar panels (battery to be added later), 300l water tank + 100l buffer OR 400l water tank (3 bathrooms and cloak room), UFH heating on both floors including bathrooms, some form of air con in the 4 bedrooms and living/dining area (5 in total), Towel radiators with electric element in bathrooms. No carpets in the house - tiles in the hallways and living/dining areas and engineered wood in the bedrooms. My main questions are: 1. Given that this is a block and block build - how do we target airtightness? The 2 options I'm looking at are either Parge coat and dot and dab plasterboard (cheaper and faster to put up) Wet plaster though I've been told this will be more expensive, take longer and also reduce thermal efficiency which means speccing thicker insulation in the external walls. 2. What are the other things that are easily addressable given the details below to make it more efficient, without drastically altering the spec? Floor construction: U Value = 0.14 W/m².K 65mm. sand: cement screed 500g. Polythene separation layer 120mm. Celotex XR4000 insulation Polythene DPM Concrete beam & block floor to manufacturer's design Wall construction: U Value = 0.15 W/m².K Render 100mm. Thermalite Hi Strength 7 blockwork 50mm. clear cavity 100mm. Celotex CW4000 insulation 100mm. Thermalite Hi Strength 7 blockwork 12.5mm. plasterboard on dabs dry lining, plus skim Pitched roof construction (insulation at rafter level): U Value = 0.11 W/m².K Roof tiles 25x46mm. treated tiling battens 25x46mm. treated counterbattens LR Breathable roofing membrane 150mm. rafters fully filled with 150mm. Celotex XR4000 insulation 25x47mm. battened services void beneath rafters Celotex PL4060 (60+12.5) insulated plasterboard plus skim Proprietary felt support tray Pitched roof construction (insulation at ceiling level): U Value = 0.11 W/m².K Roof tiles 25x46mm. treated tiling battens 25x46mm. treated counterbattens LR Breathable roofing membrane 150mm. rafters Unventilated loft space 19mm. plywood decking or flooring plywood for loft storage 75mm. Celotex GA4000 insulation above ceiling joists 150mm. ceiling joists fully filled with 150mm. Celotex XR4000 insulation Visqueen High Performance vapour barrier 12.5mm. plasterboard plus skim COLD Flat roof construction: U Value = 0.11 W/m².K GRP weather surface 18mm. plywood deck Firrings to give 1:40 fall 195mm. joists with 150mm. Celotex XR4000 between joists 90mm. Celotex GA4000 insulation below joists 12.5mm. plasterboard plus skim
  12. Thanks, all valid points. I'm in the process of getting quotes and a lot of them come with the Surrey uplift applied. One quote we had for all the heating/cooling/PV/MVHR/UFH/basic automation was in the region of £80k! I'll be doing my own research and possibly getting the designs done separately and then get the builder to do it. The answer to the other question is that I won't be doing too much myself - until the money runs out I guess! Young kids and a very hectic job means I'll have most of the work being done by a main contractor, though my plan is to do as much procurement as possible to find the best prices on things.
  13. Ground floor is beam and block floor. First floor will be posi joist - 225mm deep.
  14. They will be sliding doors and that cannot be changed. SWMBO has said so and that's the end of the matter. The chimney was put in at the very early stages when we wanted a log burner, and I'm not sure anymore. However, I've been informed that we must build it to comply with the planning as it's part of the approved plans including the stack. Not sure what the alternative would be.
  15. Very warm, very quiet and did not need a lot of heating to come on - even during peak winters. We were on floor 3 (out of 4) so had heat coming from both the top and bottom which made it even better.
  16. Answer: Sort of yes. My first flat was a well built low rise new build, triple glazing and solid concrete floors. Had MVHR as well. Current house is a single brick (no cavity wall) 1930s semi with double glazing thats about 20 years old. I can actually feel the air blowing through when I hold my hand next to the bay windows. The only reason I haven't changed them is to preserve funds for the new build really.
  17. 1. Standard MVHR. Noted 2. Monoblock ASHP to UFH ground floor only. Cooling if possible. Noted 3. UVC as you say is ok. Bigger is better. Plan is 300L and 100L buffer tank is what I've been recommended. With 3 bathrooms and a cloakroom, we're on the verge of 300L being sufficient and we do tend to use a lot of hot water through the day with multiple showers. 4. UFH on ground floor is good. Noted 5. I don't like fan coils. Unnecessary complexity in my opinion. Provide space for A2A is easier in my opinion. This is the latest advice. A2A or split air con is what I had originally planned for. The discussion I've had with someone from an energy 'consultancy' who is putting together a full proposal for me is to go fan coils which will work out about 10k cheaper than air con. And the fan based radiators are 'as good as' internal air con and can get it down to fridge like temperatures. 6. Don't know. The question was to make sure that running ASHP in cooling mode wouldn't cause too many issues with condensation for the UFH embedded under the floor? 7. No wet UFH upstairs just UFH electric under tiles. On ground floor bathrooms too. Not sure on this one. We've gone back and forth a few times on this. The latest is that we have wet UFH in all the bathrooms on ground and first floor for sure. My wife likes to run the bedroom hotter than I like - at about 21-22C and is kinda insisting on having UFH. If we were to increase the insultation in the floor and have the fan coil units in the bedrooms - would that negate the need for having the UFH? The cost for UFH is coming out to be about £7k per floor, so the £7k saved would mean we can easily fund the fan coil units with that saving (8 x £500ish). 8. Include an electric spur for towel rads if you want them . ASHP runs too cold to do much with them. Yes, updated following advice on this thread 9. Don't know. Answered earlier in the thread, standard copper plumbing pipes. 10. No thermostats in individual rooms. I really like the idea of being able to set the rooms at diff temps - but would this work with the setup we have? I think the Fan coil units will have individual thermostats as well so this may be negated by having individual thermostats for each room.
  18. To be fair, this is the document from the Structural Engineer and the architect hasn't yet finalised the drawings from his side. He's aware of my focus on airtightness and thermal bridging and my understanding is that there will be an updated set he produces alongside construction notes that should address some of these points? I'm happy to take onboard points where taping etc needs to be done and swapping of blocks to more appropriate ones and this can be in the pack that we use the main contractor who will undertake the build.
  19. What would you suggest? In the process of finalising the BR drawings which will include construction notes. It's not set in stone as such but I don't want to start changing things massively unless there's a noticeable difference.
  20. Nope - just a spec for now. Build starts in Feb next year.
  21. What change would that mean if we wanted a bigger slab?
  22. I do like your confidence but I have to say that my understanding was the same - i.e. anything related to cooling is not covered by the grant. I do know that PD doesn't cover cooling but this is one of those situations where it would be quite hard to police as the external unit is the same so how would anyone find out if you're using it for cooling as well as heating? As for PD not being applicable under sign off - something I'm acutely aware of. We have convoluted plans to do a number of things under PD as I have no desire to go back to planning for absolutely anything I don't have to - so we'll be building the house, get the sign off and immediately exercise our PD rights for a number of things - including a rear outbuilding, fencing, front boundary wall, ASHP etc.
  23. Thanks for the detailed reply. Just to make sure I understand, I'm going to break it down step by step - and please correct me if I've got this wrong. 1. Standard MVHR - no cooling added 2. ASHP with cooling function - may or may not be eligible for grant but if we have only 1 unit, then we can put this outside without going back to planning and do it under PD rules. 3. Heat pump cylinder - 300 to 400l for 3 bathrooms and 1 cloak room. 4. Wet UFH heating on the ground floor 5. Can I also put fan coils in certain rooms on the ground floor with the wet UFH? This will make them work as air con units in the summer when we run the ASHP in reverse. 6. Any modifications needed to the ASHP to make sure running in reverse doesn't cause issues? 7. Wet UFH only in bathrooms upstairs, and not bedrooms? Will the fan coils work enough on their own to provide heating up to say 22-23C to keep the rooms at that temp? And what temp can they cool down to in the summer? 8. I currently have towel rads that run off the ASHP and then an immersion element that can be turned off or on. I assume this is the equivalent of electric towel rads? 9. Stupid question: the fan coil units will have plumbing connections to them I assume - i.e. a pipe coming in and a pipe going out? 10. Why not have thermostats in the rooms? Or can we replace the thermostat with the fan coil unit which I assume will have some sort of manual control on it rather than running of a central system? With regards to floor insulation - we did speak to the architect about adding more but his opinion is that BR regs are pretty good these days, and coming from my baseline of a 1930s semi with no cavity walls at all - it's going to be a massive step up. This is what I have so far Floor construction: U Value = 0.14 W/m².K 65mm. sand: cement screed 500g. Polythene separation layer 120mm. Celotex XR4000 insulation Polythene DPM Concrete beam & block floor to manufacturer's design Wall construction: U Value = 0.15 W/m².K Render 100mm. Thermalite Hi Strength 7 blockwork 50mm. clear cavity 100mm. Celotex CW4000 insulation 100mm. Thermalite Hi Strength 7 blockwork 12.5mm. plasterboard on dabs dry lining, plus skim Pitched roof construction (insulation at rafter level): U Value = 0.11 W/m².K Roof tiles 25x46mm. treated tiling battens 25x46mm. treated counterbattens LR Breathable roofing membrane 150mm. rafters fully filled with 150mm. Celotex XR4000 insulation 25x47mm. battened services void beneath rafters Celotex PL4060 (60+12.5) insulated plasterboard plus skim Proprietary felt support tray Pitched roof construction (insulation at ceiling level): U Value = 0.11 W/m².K Roof tiles 25x46mm. treated tiling battens 25x46mm. treated counterbattens LR Breathable roofing membrane 150mm. rafters Unventilated loft space 19mm. plywood decking or flooring plywood for loft storage 75mm. Celotex GA4000 insulation above ceiling joists 150mm. ceiling joists fully filled with 150mm. Celotex XR4000 insulation Visqueen High Performance vapour barrier 12.5mm. plasterboard plus skim COLD Flat roof construction: U Value = 0.11 W/m².K GRP weather surface 18mm. plywood deck Firrings to give 1:40 fall 195mm. joists with 150mm. Celotex XR4000 between joists 90mm. Celotex GA4000 insulation below joists 12.5mm. plasterboad plus skim
  24. Pertinent details of our build 260sq m masonry build to BR standards and emphasis on airtightness. U Values Floor: 0.14 Walls: 0.15 Roof: 0.11 Doors/windows: 1.2 Wet UFH heating on both floors – ground and first. 22mm system for the first floor due to height restrictions. Missus likes feeling extra warm all the time - wants temperatures of upto 22C in the rooms. No carpets through the property. Tiles in the living/hallway etc and then engineered wood in the bedrooms Digital thermostats for each bedroom, study, living/dining area (8 in total) ASHP – most likely 10kW 3-400l UVC MVHR Solar PV – 16 panels (7.1kW) Solar battery storage – maybe, depending on price but 5-10kWH battery to be added later. This is generally straightforward and easily speccable. Where things start to get confusing is my desire to add some sort of cooling to the property. This would be in 5 rooms (4 bedrooms + living/dining area) or 8 rooms (adding studies) if we can find a system big enough. Plan A – add a separate air con system using a 5-8way multi split system. One big external unit that sits outside and wall mounted units within the rooms – both to be added in 2 years time when we regenerate funds. Part of the build would be to have power and ducting/pipework to allow the external and internal units to be connected so that we’re not ripping open walls again. Rough cost of £10-£15k for a system like this. Plan B – get a heat hump that runs cooling as well. Not eligible for grant but price difference won’t be that much. Dissuaded against this as running heat pump in reverse means issues with condensation. Plan C – get an MVHR system that also does cooling. BPC quote for standard MVHR parts is £5k for Zehnder Q600(parts only) and £20k for 2 x Q600s with Enthalpy exchanger and ductwork for cooling option. Not going to be as good as active air con but the price differential is quite significant. Plan D – get a Fan Convector unit/Fan coil unit. I’ve picked this up reading these forums and had no idea of the existence of these. But it seems that this look like radiators and can be floor or wall mounted and can do heating as well as cooling? Does this mean I only get the standard MVHR unit, wet UFH heating on ground floor and then install these FCUs in the bedrooms on the 1st floor? Do they work like air con in the summer and radiators in the winter? What additional pipework do I have to get done for these – if I decide only to get the pipework done now and the actual units added later? Make it make sense please! Would really appreciate some guidance as trying to find a company that pulls this all together in a simple package has been an exercise in futility mostly. They all want to quote or sell products that they stock and not really looking at what would be the most effective option – both in terms of installation and running costs. Thanks in advance.
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