Temp

https://www.gov.uk/guidance/buildings-and-construction-vat-notice-708 https://www.gov.uk/guidance/vat-on-fuel-and-power-notice-70119

+1 * Labour (as in actually working on site) should be zero rated to you. * Services (as in design services) are standard rated and not reclaimable. * Materials you buy are standard rated and reclaimable. * If someone does "Supply and fit" on one invoice then both should be zero rated to you. If it's on separate invoices the materials part should be standard rated and reclaimable, the labour part should be zero rated to you. Connection of services should definitely be zero rated to you. Request a revised invoice & your money back. Any problem and you can refer them to the relevant part of VAT Notice 708 and point out it is their legal responsibility to charge you the correct rate. I had to get a new invoice from my water company. https://www.gov.uk/guidance/buildings-and-construction-vat-notice-708

+1 See... https://www.gov.uk/guidance/goods-and-services-you-can-claim-for-under-the-vat-diy-scheme Under "B" it lists So its standard rated to you and cannot be reclaimed.

Try asking your questions here. Many of us have been through the process.

Sounds like a plan. Although if you have three phase I'd be inclined to keep it. Might be useful in future for electric car charging.

Running flashing up the fascia sounds like a bit of a bodge. Can't really see an obvious alternative. It is possible to put an internal drain in a flat roof but that's also something to be avoided if possible. Its one of those things that works if done right but is a pain if not. Again can't see you have much choice.

We have a travertine counter top basin with wall mounted taps. I wouldn't go with travertine again because it stains but everything else about them is great. You can get them with overflows built in... https://www.victorianplumbing.co.uk/costa-600-x-370mm-counter-top-basin-0th-ves009?campaign=googlebase&gclsrc=aw.ds&&gclid=CjwKCAiA0svwBRBhEiwAHqKjFs3zrhMpnMhPic36B_xvzLKTVmclDSsqovoLNc6mzWn8M4idAcguTxoC_n8QAvD_BwE or you can add one hidden in the wall that bypasses the plug when the level gets too high. https://www.tapsempire.co.uk/product/ideal-standard-idealflow-hidden-basin-overflow-n8326/?gclid=CjwKCAiA0svwBRBhEiwAHqKjFi_5DK62Xm2p-79kvMlxftgAc8GxTC07UWv_k5vHNIVAWpCCs9KhJBoCfZ0QAvD_BwE Taps can be wall or counter top mounted. Our wall mounted taps seem to stay cleaner for longer as water from wet hands doesn't run down the tap or puddle around the base of the tap. Some counter top basins even have mountings for taps. I fixed our basin down with a bit of silicon same as our shower glass panels. They aren't going anywhere. The basin is also fixed down by the waste but you arent meant to do that (our counter top is also travertine and I forgot to make the hole big enough to clear the nut). I would avoid a basin with a very rounded bottom as it would be hard to clean under there (other things with rounded bottoms are fine by me :-)

We had two blokes try and steal a site workers truck in broad daylight while he was in it. He was having his lunch and bent down to pick up something from the passenger foot well. When he sat up again there was a bloke feeling around the front wheel to see if any keys had been left there. Ran off when the door opened followed by his mate lurking in the church yard next door. That would have been covered by his own motor policy but it could easily have been my own kit or stuff we had on hire.

Yikes. More than one house (and a few cathedrals) have been burnt down by a careless plumber waving his blow lamp around. There are 11 fires a day on construction sites according to.. https://www.firesafe.org.uk/fire-safety-on-small-construction-sites/ But most people die on construction sites by falling from height. Did your BCO know you didn't have insurance? Some won't even come onto your site if they know that.

Basically the boiler puts hot water into the buffer and UFH takes it out. The boiler ON time depends on how long it takes to fill the buffer tank. The boiler OFF time is determined by how fast the UFH empties the buffer. The two times added together give the cycle time. If I've done my sums right a 29KW boiler would make about 0.35L/S or 20L/min with a 20C uplift. So it would take about 5min to raise a 100L buffer tank by 20C (ignoring any draw by the UFH at the same time). To calculate how long the UFH would take to empty the buffer you need to know the power the UFH draws but we already know its less than the minimum the boiler can deliver (10KW?). 10kW is about 0.12L/S or 7.1L/min with a 20C drop between flow and return. So the UFH should take at least 100/7= 14min to empty the buffer. So the cycle time should be around 5min ON and 14min OFF. However the useable capacity of a 100L store probably isn't 100L. It probably depends on the position of any stats on the tank. I'm sure things aren't quite that simple in practice so you should get the buffer tank sized by someone providing a warranty. Eg Heating Engineer. All I have is O-Level physics and some back of the envelope calculations.

2 port vs 4 port buffer tanks.. https://blog.heatspring.com/2-pipe-versus-4-pipe-buffer-tank-configurations/ Apparently the 2 port set up is more efficient as hot water only flows into it when needed not all the time.

I think in Scotland you need a Road Opening Permit.. https://www.gov.uk/road-opening-permit-scotland Just one councils view on this... https://www.scotborders.gov.uk/info/20031/roads_and_pavements/744/road_permits My guess is the process for getting one will require you to provide info on the contractors qualifications and insurance. In England I think they are meant to have £2m public liability insurance?

One possibility might be to fit smaller jets in the burner or even a smaller burner? Would need to talk to the boiler manufacturer. We fitted smaller jets in our oil boiler but oil boilers don't modulate like gas boilers, they run flat out all the time making cycling even more an issue. We did it because Grant said it improved efficiency a few % as well as reducing Max power. On a modulating gas boiler I don't know if smaller jets reduce the minimum power or just the maximum? Reducing the max power could impact the DHW flow rate.

It sounds like your diagnosis is correct. Does the UFH appear to be working OK otherwise? I've heard of some builders making silly mistakes such as using airated screed which inadvertently insulates the floor loops a bit. That would cause return temperatures to be too high and shut down the mixer. If you have to fit a buffer tank you can probably get away with a simple buffer tank (eg not one that splits the system). The main issue will be getting the sizing right. Some references suggest 10L per kW of boiler output, but they say that's not the minimum power but the "start up power" which presumably is higher. That would give a tank of perhaps 10*10kW=100L? Too small and it won't lengthen the cycling enough, too large is less an issue but it will leak more heat than necessary.

What temperature is the manifold mixer set to? If its very low then increasing it _might_ help a bit. Note there is usually a limit/safety stat on the manifold as well as the mixer. The safety stat is usually set to something like 50C or lower for some floor coverings that might be damaged by high temperatures (Karndean?). The mixer must be set lower than the safety stat. Short cycling reduces efficiency, a bit like stop start driving a car. Its worse for an oil boiler than a gas boiler. I was concerned our oil boiler would short cycle and so intended to put a buffer tank between boiler and UFH. In the end we opted for a thermal store which buffers DHW as well as CH. Heat banks are just a variant on the theme. More after Dr Who!

On my outbuilding (timber frame, tiled roof, oak clad) on clay I... Removed about 12" of soil and compacted the ground with a wacker plate. Laid 6" of hardcore (compacted in two layers) then a thin layer of sand (compacted) about 1ft bigger than finished building all round. Staked 6" shuttering using rebar stakes (dimensions of slab slightly smaller than finished building so water dripping off cladding would fall outside the slab not on the top of it). Just about remembered to add a length of mdpe pipe for electrics to come up through slab later. Laid membrane into shuttering (prevents water draining out of the concrete). Filled with 6" readymix concrete and levelled to top of shuttering using a long length of 4*2 (the levelling part was physically hard work). I didn't have trees to worry about but if I had then would have added mesh raised up 3" before the concrete pour. It would have been easy to add a trench around the edge to make it deeper for block walls. Perhaps make trench wide enough to get the Wacker plate into it?

I was also considering making one. The holders are normally designed for 10"*2.5" carts but there are "jumbo" versions which are 10"*4.5" and double length 20"*2.5" both of which should have less resistance to the flow.. You could also use two in parallel to boost flow rates. Example Pair of jumbo carts but these are in series.. https://www.finerfilters.co.uk/finerfilters-10-jumbo-high-flow-double-water-filter-housing.html?gclid=CjwKCAiAjMHwBRAVEiwAzdLWGInx_E8xNuP2QWESQWLjyT4U34xkTcn-z_OkEJy3LD7bNA7lyMnwehoCq8kQAvD_BwE Haven't yet found a jumbo size refillable cart but haven't looked hard as other projects are going to keep me busy for quite a while. Some water filter holders have/haven't got brass thread inserts which seems to affect the price a lot.

Interesting use of ball bearings for bushing. I used skateboard ballbearings on another project and found they pressed into my PLA prints really well. Think they have a slight bevel on the edges which help.

Google found NHBC.. http://nhbccampaigns.co.uk/landingpages/techzone/previous_versions/2006/Part6/section4/sitework.htm Section 6.4

Think this cistern is just 96mm from back of cistern to front of wall (80mm cistern and 16mm for the plasterboard and tiles).. https://www.ukbathroomstore.co.uk/pura-cc100-super-slim-concealed-insulated-pneumatic-cistern?dfw_tracker=34263-CC100&gclid=CjwKCAiA6bvwBRBbEiwAUER6Jf7NtV2SrNHriTpCeWY-DxudR5Y6VTUaSbPbvDy3hX9HQYJU1_QCLxoCsv8QAvD_BwE So a 110mm waste pipe would be the limiting factor eg back of pipe to front of wall could in theory be 110+16mm = 125mm? Would have to be a floor mounted WC and horizontal studs only. Getting a bit carried away here :-)

Think the shortest wall hung is around 480mm so add 145mm and you get 625mm.

With short projection pans check the seat will stay up. Some may need low profile seat and cover?

Usually the cistern and pan connector/bend are similar depths. If you find a really narrow concealed cistern then.. Gberit have a pretty short right angle bend/pan connector they use on some of their frames... https://www.tapsempire.co.uk/product/geberit-hdpe-bend-with-connector-for-wall-wc/?gclid=CjwKCAiA6bvwBRBbEiwAUER6JS-hK4K4TgfYTUUF4UnumZIJx615fJ76S1f_4Wr2oNw9bIl69gmHwBoCPpIQAvD_BwE

I don't know if that's correct but.. If the wavelength depends on the molecular/mechanical properties it shouldnt be surprising that that water and ice have different lines because they have different mechanical properties. https://en.m.wikipedia.org/wiki/Absorption_spectroscopy

Just had similar answer from a son. Some absorption lines depend the "electronic" structure and others the "molecular" structure of the gas. The electronic structure is all about electron orbitals (the "fixed" gaps between orbitals leads to absorption lines having fixed wavelengths). The molecular structure is its vibrational and rotational properties/modes. This video covers lines caused by the electronic structure..