JohnMo

That is a small cylinder when your used to seeing a heat pump cylinder. Looks tidy. Nice insulation joints.

If you have trickle vents replace for humidity activated ones. Click vents or any other manual vent will just get closed at some point in time and never be reopened. Humidity activated ones will be almost closed all the time, only when required for they open. While your at dump the intermittent fans and install dMEV one (Greenwood CV2 or 3) You should only have trickle vents in dry rooms not wet rooms, as they allow a short circuit of air flow if installed in a wet room

So the main drawing would need to cross refer to the cross section drawings as different wall may be built in different ways. If your house isn't air tight don't bother with heat recovery. Fans and trickle vents are ventilation, without it everything goes mouldy. A decent smart dMEV fan will run a very low background flow rate, and only boost if needed. Trickle vents can be made to be humidity activated, so only open when needed. Think about the system and plan, it will be silent, it only ventilates at the minimum level all the time. You only have trickle vents in dry room, and dMEV fans in wet rooms. Heat loss is minimised.

You have a dinky heat pump, you could easily pipe in 22mm, so if using 28mm don't loose sleep. The difference in pressure drop is very small.

Your MVHR will do that on its own. We only use the extractor on rare occasions now (smelly stuff and only on low) MVHR does a good if it on it own. A house with MVHR isn't the same as a normal house with intermittent fans. House feels and act differently. Anything else is a design thing down to personal preference.

For UFH you should be bonding the flooring to the screed. An underlay acts as insulation

Just used a pump that has the timer and adjustable thermostat built in to it, nothing complex, got it from eBay for about £125. https://www.completepumpsupplies.co.uk/lowara-ecocirc-pro-15-1-65-u-circulating-pump?srsltid=AfmBOool1Fk6POF4FC1q5gROaJ7sAXKec93riA7uyJc3N1OgDdt_bucDE48 The circulation loop is just a single pipe with pump and check valve. The water is just water in an unvented cylinder - in my case heated by ASHP, but could be heated by anything that heats the cylinder. Water is drawn via normal DHW pipes, and a additional pipe takes the water back to cylinder and injects it back in the cylinder. Why is secondary circulation circuit anything to do with an ASHP, it has nothing to do with heat source. It's just part of the DHW distribution system.

You can when building a house put pipes with in insulation etc. you can also use thermostatic and timer control so little or no impact on house temperature, any time of the year. Ours runs for 2 hours in the morning only and the pump only runs until the return temp hits about 35 degs. This is the impact on cylinder temp over a 3 hour period including two people using the sinks etc. Switching on the tap and having immediate warm water is great, no waiting and endless water draw off.

I use a similar set of terminals on my heat pump - different make. But you can just set WC to run in the background as your base setting and when your secondary contacts close the second temp comes online so you have WC plus a degree or two or minus a degree or two. Any simple thermostat would do that. You can play different tunes with the two settings, boost when it's cheap rate. Bullet proof WC, very low and loose WC curve, and a thermostat to allow a boost on flow temp only if needed. If you get paid for export PV just export it, if you don't set second setpoint 5 degs higher than normal WC and stuff your floor and cylinder with energy. Doesn't work well with radiators though.

It's not really, it a little bit variable based on kWh used per year, as you also have to account for standing charge, which is eliminated with a move away from gas. The less gas you use the bigger the standing charges have on the real cost of gas. So if you use 10000kWh doing heating and hot water, with standing charge is around £810. Converting to HP you only need a CoP of 3.4.to break even. If you are near passive heat loss the gas consumption could be around 5000kWh or lower. So gas £460. So CoP needed is just under 3. The lower your consumption the lower the cop you need to break even. I had a hybrid system set up last year and frankly, when you do the maths, the running cost was bonkers high - hence gas had to go.

Really depends on tariff - I only need a cop of about 2, on Cosy with battery to plug gap between cheap periods. But generally 4 with a normal flat tariff. But on energy monitor, people are getting SCoPs of 5 plus. A well sized heat pump with a decent modulation range, and running without buffer and open system on WC, should output an average CoP closer to 5.

Compression fitting and pipe are different from solvent pipe so they don't mix. .a very quick search on Google brought up this and many different versions https://www.screwfix.com/p/flomasta-p-trap-w-dual-appliance-inlet-white-48mm/191JN?gclsrc=aw.ds&gad_source=1&gad_campaignid=22599672207&gbraid=0AAAAAD8IdPzzuvaJQxmaSUVQQDgPQKGCI&gclid=Cj0KCQiA5uDIBhDAARIsAOxj0CE5W65nMeWK6Jhk3C764IBsIqQk4Cb0qIbW7qHAzgaUoTTDB7lbdmYaAmPBEALw_wcB Or this from B&Q etc

We had to add an earth rod in addition to the the SSEN one, for running in island mode. But if you make some basic assumptions 1. Mains is off and cable is broken or in your case not there. 2. You no longer have a safe proven earth path. So a fault in house has no earth route in island mode. So you need to add an earth spike for that condition. No earth spike no ground route except via you. Doesn't sound that safe to me. So install earth spike for island mode and be safe, would be my answer.

It's basically mandatory not to use oil and gas in new build in Scotland, if they can it with way worse weather than England, the more natural choice is heat pump, storage heaters etc. And in Scotland you don't get a grant in a new build. So why should England. Hopefully the grant will just disappear. Cost will become realistic. If you have a big rambling house, you can afford to upgrade the heating yourself, so why should the tax payer help you out? Yep I have a heat pump, self installed didn't cost much, more expensive than a combi, but no more expensive than a decent system boiler and cylinder. But more importantly it's way cheaper to heat my house via HP than boiler. January 2022, at today's rates it cost me £100 in gas including standing charge. Via HP it will cost £65 ever with a cop of 3. Not the point really. A new build doesn't need a gas or oil boiler, however much you may disagree. 90% of new builds only need a sub 6kW heating (most less than half that), which is easily done by a heat pump, in most cases a gas boiler is way over sized for a new build, so why does that choice need to be there? Easy take the choice away from them, don't let them decide. Not really I built my house with a boiler, added heat pump for cooling as the boiler cannot do that. Kept the boiler used for heating then hybrid then straight heat pump. So have tried every combination - hands down just ASHP including cooling all summer is way cheaper than gas was just for heating. They are not allowed as permitted development, you need planning permission to install, if you follow the rules.

Suspect we will find out on a couple of weeks, if there is no change in this budget, there never will be. The options that have are vat, and the green levy applied to to electric. If electric came down in cost ratio with respect gas, some people may think about a heat pump, but for the 99% replacing a normal boiler, suspect it's not even on the radar - they all believe press hype, they are crap and would never work in their house.

About time - grants just encourage higher costs and fly by night installers. A heat pump install for a new build should be mandatory, with zero grants anyway. You can get a decent heat pump for around £2k, which is about the same cost as a decent boiler, that does priority domestic hot water and weather compensation. Which again should be mandatory.

I asked Google why did I do it, as it now 5 years since I did it. Lime is added to cement in mortars and renders to improve workability, flexibility, and water retention. These properties make the material easier to handle, create a better bond with the substrate, and increase durability, especially for older or softer building materials. Lime is sometimes combined with cement to balance the strength and setting times, allowing it to be used for projects with different requirements. Benefits of adding lime to cement Improved workability: Lime makes the mortar smoother and easier to spread, which helps achieve full, well-bonded joints. Increased flexibility: Lime adds flexibility to the mix, which helps prevent cracking caused by brick and mortar expansion and contraction. Better water retention: Lime holds water within the mortar, making it more cohesive and improving its application to porous surfaces. Enhanced breathability: Lime-based mortars are more vapor-permeable than cement-only mixes, which allows moisture to escape and prevents dampness and frost damage. Improved bonding: Lime provides a better bond with the substrate, creating a more durable and protective finish.

Basic comments - drawing for planning and warrant will be different, so you will not have combined drawings. So do you have planning permission already - if so drop the planning permission from the drawing title or vice versa. All drawings are light on detail. Should include details of proposed build-up etc or make reference to additional drawings. If this steel interacts with the outside world it will insulating. Not sure if it also need fire proofing - ask your structural engineer. Still has address on one or more drawings Larch Cladding, in 'rain screen' formation with 8mm gaps. - be prepared for a wasp invasion, they will love it. Your ventilation fans really should be upgraded to dMEV, so you have silent ventilation that works. Intermittent fans are awful - the work of the devil.

Why would 1 and 3 be the wrong way around? Just check mine, not the same make but exactly the same terminal positions. Only difference between different units is if they are configured to be left or right handed, but then 2 and 4 and 1 and 3 swop positions. Maybe different brands for different countries, or selling you the same thing at different price points via another name

You could always collect, process and use rainwater for grey services. So harvest it.

The next thing to look at is the totals over a day, to get a better understanding of what's going on. Then you see affects of standby etc on the overall efficiency. So there you need to get daily heat output and electric input over the same time period.

I wouldn't get bogged down just getting stuff from one supplier Where you have you red arrow one of these would be ok. Fits on to the end of 90mm duct. https://www.epicair.co.uk/products/zehnder-circular-decorative-coanda-effect-grille-renoventil-dia-90-mm-white?_pos=3&_sid=05581fab4&_ss=r or this https://www.epicair.co.uk/products/zehnder-rectangular-decorative-grille-renoventil-180-x-112-mm-white?_pos=4&_sid=d9d91635a&_ss=r Or you can add one of these to duct for fitting the nozzle https://www.epicair.co.uk/products/zehnder-renoventil-grille-housing-connects-1-x-renoventil-grille-with-1-x-dia-90mm-comfotube-l400mm?_pos=1&_sid=d9d91635a&_ss=r You add one of these to adjust flow rate (inside duct) https://www.epicair.co.uk/products/zehnder-comfotube-dia-90mm-adjustable-airflow-regulator-30mm-length?utm_source=google&utm_medium=cpc&utm_campaign=21384778218&gad_source=1&gad_campaignid=21384779943&gbraid=0AAAAAD8qV0ni71CLZLxWVo7kHMQY7RIbV&gclid=CjwKCAiAw9vIBhBBEiwAraSATknMvxLQHHFWv8yChf5Tfwn1HP9BGK3_M2f5cWo62f8FWq2Hoh72NRoCw6oQAvD_BwE I use Titon MVHR, they seem to work well There is this on eBay https://www.ebay.co.uk/itm/267457702512?_skw=mvhr+heat+recovery+ventilation+unit&itmmeta=01KA12031H4E0JGRWA80WW8T47&hash=item3e45b8aa70:g:3RcAAeSw6hto4ONL&itmprp=enc%3AAQAKAAAA4FkggFvd1GGDu0w3yXCmi1ftkXG3VGHn%2FAZB7xfE1d4ZLICggnVhqn0vABQmOR%2BHFGcnlPm26BOFdnUIIcPXqU5amfhqN8Q3z6%2FdJRsYXBMLzxoxbUFZJLldveUPcFqMeWNYZhY2wg%2B15pzVILjAkXRaVDtPKKQ401lReb%2Fk8Bl5uJIJpNctQAchApPDZ19CGTzUXpL%2Bf4beePIJfZYn%2BTyUsNIeJ%2BSlLQ8URAO%2BmrvaJCPUBM1q1HR0zhPGIvV3k5YyoPT2YdBUtKercDV9QiSxZTmyW05IczjqOJb80TMZ|tkp%3ABk9SR4yxgKLQZg

Why not just go 4/5G? £20 for unlimited data. Get one these hubs for £58. https://amzn.eu/d/jlWgSgm Add an external aerial if needed

Masonry paint or emulsion. Try on a small area, make sure it stays put before you commit.

Mix ratio is on here https://forum.buildhub.org.uk/topic/25228-airtightness-parge-coat-vs-airtight-paint/