Robs931

Yes new build. Block and beam, 150mm PIR and 75 screed.

I have DIY installed my UFH system a couple of weeks ago and I'm now waiting for the screed to be poured in a few days time. The layout was designed by the firm I purchased the UFH kit from with 150mm pipe centres throughout the entire ground floor, which I adhered to thinking everything was fine. I have since been in contact with some ASHP companies to get quotes and one of them mentioned a lot of UFH companies don't perform proper heat loss surveys and just use 150mm centres as a default and I may need 100mm centres in some rooms. I have since carried out my own heat loss calculations to the best of my ability using the NRG online calculator, and as far as I can see the only room that might be an issue is the kitchen due to the reduced heated floor area as there's no pipes under the kitchen units. The room has a total floor area of 26.2m², a heated floor area of around 20.3m² and a total heat loss of 1446W according to the NRG report. There is a lot more glass in this room compared to any other which I assume is the reason for the higher heat loss compared to all the other areas of the house. If I understand the UFH output chart correctly, at 150mm centres a MWT of 35°c will give a heat output of around 60W/m², which over 20.3m² gives 1218W, a short fall of 228W. But if I went to 100mm centres at the same water temp it would output around 70W/m², which over 20.3m² only gives a shortfall of 25W. The room has 2 loops, one 64m and the other 78m. My question is, as I have a fair roll of pipe left, should I be thinking about closing the pipe spacings up to 100mm on the 78m loop and replacing the 64m loop with new pipe at 100mm centres too? Or would the system be ok left at 150mm and just be a little less efficient to run? Ideally I don't want to rip up what I've already installed, but if leaving it means the kitchen will never get warm then I need to do something about it now whilst I still can. Thanks in advance.

Hi everyone, So my timber frame build at the moment has been designed with an arched soldier course above every opening. This currently is to be formed with a straight steel lintel and a preformed uPVC arch former sat on top, but I am now unsure how this will look once the windows are installed. This is due to the fact that I believe the windows will be set back in the brickwork around 50mm and as far as I can see in pictures online the uPVC arch former is only set back maybe 20-25mm from the face of the brickwork. I'm unsure how this possible 25-30mm step will look between the window frame and the lintel/arch former. Does anyone have any pictures of their windows with uPVC arch formers which might give me a better idea? My other option would be to use timber arch formers and remove them after the brickwork has cured leaving a self supporting arch and then fit a filler piece above the window to fill the arch. This would at least mean that the arch filler is recessed in to the brickwork the same 50mm as the window frame and in my head look better/neater. But my building regs drawings state the use of a steel lintel with uPVC arch former, if I then changed to timber formers would this be an issue with building regs? Would I need to resubmit updated drawings or anything or is the BCO not likely to even notice the change?