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Hi all, Looking forward to getting some top tips from those that have been here already. Starting the journey to turn this old cow shed into something a little more habitable. Two areas I'll be after some advice on right away are PSTP & out letting of discharge & also starting to understand Solar in a bit more detail to get specs right. Current outline spec is SIP build / Air source underfloor / Solar / Batteries / MVHR - starting building regs & SAP side now. Have done loads of renovations before but not a ground up build using any of the new 'renewable' tech. We have to retain the original concrete frame for the central section but the rest is from scratch.

Whilst I log my energy use including what is used by the heat pump and am happy with it, I would not say I agree with "The country is ready to go heat pump crazy" I firmly believe a heat pump installed in the right situation and set up properly works well. But I don'r believe all the UK's housing stock is ready for heat pumps and I don't believe there are enough installers to do it properly, and any mass rollout into unsuitable housing with poor installers will just end up in huge disappointment.

There's no hard and fast rule - HMRC basically does what they want, and in general that involves rejecting things unless there's a clear case to the contrary. Personally, I suspect there's no way you'll win an argument that you've installed a grand's worth of speakers to hear a doorbell.

2nd pic is Llanberis. The WAUNFAWR one is all other pics. Went for a mountain chalet effect inside

Last (and only) time an architect gave me a build price, I just went and built it myself for half his estimated cost.

As I promised I have created a first-cut model of weather compensation, attached. Its based on the Mitsubishi PUZ-WM112 performance data, which is pretty comprehensive. I have modelled the CoP with 5 different W/C schemes and none, estimating the CoP as a function of flow temperature and ambient by linear interpolation. Weather data is average daily temperature for 2022 from the Met Office Central England database. The average daily temperatures are collected into bins 1 degree wide, the number of days in each bin counted, and then the load and consumption for the conditions calculated and multiplied up to get the total annual for that 'bin' according to the w/c scheme selected. The totals for all temperature 'bins' give the total consumption over the year. This is compared with the total demand calculated the same way to get an average CoP, and the total for any particular w/c scheme compared with scheme 'none' (ie no weather compensation) to estimate how much w/c saves. The 'ideal' W/C curve is based on adjusting flow temperature to precisely match demand at ambient temps other than the design temp, using the heat output curve of a typical radiator (which varies as (flow temp-room temp)^n where n=1.3). If someone can tell me how UFH output behaves as a function of flow temp I can model that. Other curves are variants of this, Simply put, it suggests that the various weather compensation schemes I modelled save between 11% and 15% over no compensation at all, which is, frankly, disappointingly small (so I am a little nervous a mistake has been made - but I cant find it). The model takes no account of inefficiencies due to cycling, only the improvement in CoP. This might be significant, if anyone has any figures it might be possible to add them in. I will write it up in more detail over the next few days and - health warning - there may still be errors so, until its been peer reviewed or checked against real results, treat with extreme caution. If anyone wants to critique, contribute suggestions, discussion or actual results of comparing the effects of weather comp, I suggest to do so here so as not to hijack other threads. WC Simulation.xls

Starting with the solar panels part, REC is the manufacturer with a good reputation for reliable products. If they are installed by an 'REC Pro Installer' then you get a 25 year warranty on the panels that includes the labour costs to swap out any that fail. Check this link for your local installers. https://www.recgroup.com/en/installers/search The GSE integration is a mounting system for the panels that fixes directly to the roof slats, so the panels become part of the weather proof cover for the roof with the edges filled in with normal roof tiles. Presumably this is for a new or replacement roof project. With 22 x 365 Watt panels, the peak output in Summer with all at the optimum slope angle on a South facing roof would be 8030 Watts (8.03 kWpeak). But is your roof area all South facing, and big enough to contain all 22 panels, or do you have East and West roof areas big enough for say 10 and 12 panels? To cater for different alignment of roof areas, the inverter has 2 string inputs that operate independantly to optimise the output of the connected panels. So you could have say string 1 of 10 panels for the East roof, and string 2 of 12 panels for the West roof. You can get a prediction of the panel performance for your location and roof layout by using this calculator:- https://re.jrc.ec.europa.eu/pvg_tools/en/ Choose your location, even down to your street level. Input the PV peak power (all 8.03 if all facing in the same direction). Slope = angle of roof from horizontal. Azimuth = angle from due South (East = -90, West = +90) Click the 'Visualise results' button to see the predicted kWh output per month. Run the report twice with different PV peak power and azimuth if you have 2 roof areas, then add the monthly results together.

You're right there. There was no way I could get rid of roof drainage on site due to size and a high water table so our BCO and Highways agreed that I could run the water straight onto the road. It just ran down the road until it found a ditch. You just need a pragmatic BCO.

Rough guess, £130k. That's based on a laying rate of £100/m for 160mm PVC, 10x MHs at £1k each, £10k for traffic management and £10k for design and management, and 20% uncertainty / contingency. Assumes no water course crossings, private land, deep excavations, utility diversions or difficult ground conditions. Those rates above are from a few years ago and from a large framework supplier so I'm not sure how realistic....

cant see it being a problem, double chambers would be needed. A standard cheap pumped chamber at the house feeding the treatment plan wherever you put it. The 63mm pipe they use is an absolute bastard to use be warned!

Some progress . Need a 🍷 break now

Yes it was. I tried not to have contact with the planners once I had got approval due to a less than good relationship with them after I had got planning approval against the Head of Planning Department's recommendation. I just carried out the conditions and did the build.

Gotcha. I didn't know that was a thing! Approved Document H2:1.71 says alternative implementations need to follow BS6297:1983, which doesn't even use the term drainage field!

I deffo can't help there then - best of luck!

I should probably add that I initially asked a very specific question with no context as to what problem I was trying to solve. This is because I've noticed in my brief time on BuildHub that the more one explains, the greater the likelihood of "you shouldn't do it like that" replies. However, I think I've now created the opposite problem where people are trying to be helpful but with incomplete information. Suggestions on what balance to strike would be welcome

I agree - perception is the key . A tenant will moan their room isn’t 21 degrees . It’s actually 20.5 . They request I turn it up to 22 . I do nothing . Hour later ask them if that’s better - they say yes .

Yeah I’ll probably do that as it should ‘square ‘ it . I’d just rather the frame was all square and fixed I.e rigid .

It is a statistical 'thing'. There is Absolute Humidity, the actual amount of water, by mass, whether as solid, liquid or vapour, in each cubic metre of air, then there is Relative Humidity, what we tend to talk about most as it is easier to measure and is the fraction, in percent, of the amount of water, as vapour, that can evaporate off a surface of water, into a cubic metre of air. Sounds a bit complicated, but it takes air pressure into account and you may well he terms like vapour pressure and partial vapour pressure. No need to worry about the terminology. It is possible to calculate one from the other, but easier to use an online calculator. What it basically comes down to is that even if you have extremely high external RH, once that is warmed a bit inside the house, the RH drops. I am currently at 5.6°C external temperature and 90% RH, once that air has warmed up in the house, the same mass of water is still in the air (about 7 grammes/m3), but because the temperature is now 21°C, the RH is now 42%, which is probably too low for fungal spores to start sprouting. So getting the place warmer will drop the RH, as long as it is not totally airtight, like a submarine. It is why forced ventilation is used in airtight houses. There is a lot of chat about CO2 levels, but high internal RH is what will make you feel uncomfortable, and unless you are used to it, sleepy. Think a Far Eastern holiday with 40°C and 99% RH, two drinks and it is tiring. Never seen anyone sleeping out in the open in the Central Antarctic, the driest place on Earth.

A common mistake!

Ok. I'm slowly coming back around to room by room ventilation ( via MVHR or other ). Detailing internal junctions ( if IWI ), eg where internal corners meet, where ceilings meet walls etc etc will be of absolute and critical importance here, or you'll get very localised issues where ( for eg ) dot and dab has bridged the covered cold wall to the interior of the room. This is something I have suffered myself, where I let dab squeeze between the insulation of the two abutting insulated plasterboards in my bathroom. You can literally draw with a pencil where I have done this as the damper part of the wall reacts after every shower is taken. A sloppy installer will just bring the problems further forwards, so you need to vet the installer and be firm with what you expect from them, what the issue is that you're resolving, and how you wish to understand how it is to be carried out.

In that case you are looking at a medium duty ductile iron cover. Often called a driveway or car park cover. Good for around 10-12 tonnes and cheap as chips for what they are. Frame depth depends on the lid size.

If it helps you feel better. I love the doors. That's going to be a lot of drilling into the concrete slab for the bits of wire.

What vehicles will use the drive? How likely is it that wheels will go over the lid? How will the drive be finished? Will you set the lid in concrete or tarmac? Or sets etc.

Take photos just in case. They'll be more interested in the drainage around the house and under driveways etc

Hard to change yes but it can be part of the residential area and doesn’t necessarily need a fence between it and the garden. Different councils take different positions on it.

It’s quite expensive But if your only doing one wall it’s not to bad It comes in every shade and colour We deal with two designers who incorporate it Into what seams like every job difficult to tell from the photo I’ll see if if can find some better ones

Hi SteamTea I was hoping you might be able to help. How well does your prediction/model match actual heat used?

Matters not one jot what you’re doing after, but this is the only way I will detail these junctions from hereon in. The render is just about the only thing that will stick, and STAY stuck. No good being great on the day, then gives up over the next couple of years when it’s waaaaaay too late to do anything to quick-fix this. Check with BCO and read up on manufacturers recommendation for these reveals, they should provide guidance. BCO will probably know the square root of fcuk all here, and could cause undue stress / work so take that info and choose what you do with it. FR should be a concern, as if an open flame gets to the EPS, it’s “goodbye house” at a rapid rate of knots. Not often discussed.

I use an IR thermometer to measure the difference between flow and return temp. Given you have auto balancing actuators, this should be done for you (assuming they're working correctly!).

Or a volumiser, in the flow or return piping, then there is no mixing of the flow and return water. Or if installing a buffer install as a 2 port buffer between the flow and return, so its only engaged as zones close off. Or stop zoning everything in to small areas/water volumes. A recent test (simulation) was showing a reduction of 1 on CoP, with buffer compared to without buffer. Both running WC, but with buffer HP required increased HP flow temps to overcome the mixing within the buffer. If your are getting a couple of batches of cheap electric, a large buffer could be beneficial even with the hit in CoP. But you would need a low energy consumption house to make a real benefit or a very large buffer.

Currently 2G wood frames (no trickles). 3G replacement getting fitted next month.

Just FYI you'll need BC out to inspect before you fully backfill. They need to see depths and adequate bedding etc.

Runnat original depth. Bear in mind minimum cover for building control. Also, a deeper pipe is less likely to be struck in future. Also allows you to run other services on TOP, in the same tewmxh, if needed.

As @Nickfromwales said, don’t worry too much about the engineering, be more concerned about the execution. Is it done according to engineers specification? If in doubt, send pictures to SE for comment.

Assuming the connection is under the pavement then you might as well keep it deep till the first chamber. Then assess runs and depths needed from the build/s and put their chambers in to suit. Bit of extra digging is much easier and less stress than working with shallow drains

Just get a continuous layer of dab running the full width at 750-950mm off ToC, for the base units to be affixed to, and the same at x height to take the wall unit fixings.

Tell them the room will become a cupboard. Cap the pipes. Instruct BCO to delete it. Simples.

Double glaze sealed window units need an external air path to the edge seal. If you block it, then there’s a risk the seal will fail, and the window will eventually mist up internally. This is either from water leaking in from outside, or humid air leaking in from inside. I think from the pictures, the air path is between cill and the main unit - piccy below with red arrow. I’ve got similar, and I kept that opening clear for that reason. When I removed the glazing from ours (swapped for high spec), I could see small holes drilled at the bottom of the frame internally so the airspace around the dg seal connected to outside via that slot. Totally agree with the rest, and method of foam+sealant.

Whilst "double glazing" was seen as the panacea to all cold evils, installers were often just scammers keen to maximise profit. New windows would be deliberately undersized to to allow quick fitting with no hassle. The subsequent gaps were often not filled but covered with trim. Sills were "glued" on with mastic etc. The TV series White Gold was closer to the truth than you can imagine. Those gaps...fill them as best as you can. I'd mask the window with tape and where you can, inject Illbrück FM330 using a proper applicator gun. When set, cut off level with the window using a sharp craft knife. Keep the windows shut whilst it's setting. Then add mastic beads all around. A Fugi Cramer tool set will help with the mastic beads. Unless you want to hack back the reveals inside and see just what atrocious gaps they've left and really do it properly. I kid you not I have 1" gaps around mine.

Comparable, I'd say, to the real cost of installing a fossil fuel boiler and multiple radiators - especially if not on mains gas. There are two main issues that I can think of. Obviously if there's only one outdoor compressor unit, then the indoor units can only cool or heat together. Less obvious perhaps is that the simultaneous heating/cooling capacity will be lower and all indoor units will go idle during defrosting mode. Neither of these is a show stopper but having one-to-one indoor outdoor units doesn't add a huge premium when most of the cost is in the indoor units. Here's the two outdoor units that provide us with a total of 7kW of heating for around 1.5kW of electricity. Quite a bit smaller than an ASHP and more practical to hang on a wall.

We are a slightly higher building reg self build on Skye. Nothing fancy, just a modest three bedroom 138m2 completed in 2020. Our installation consists of three extraction points in our en-suite, bathroom and utility this goes into a metal ducting into a mini air source heat pump on top of a cylinder. It takes that air and heats our domestic water (not heating) and blows cold air outside. It also extracts moisture through a pipe to the outside to help with humidity. It was quite cheap to install and is cheap to run. It's very consistent in the energy usage as it's not trying to take cold winter air outside like an external heat pump therefore always achieves a very higher cop. Points to consider: sound proofing - our sits in a cupboard in the utility room. No noise in the house, but when working its slightly louder than a fridge freezer. We have it on anti vibration mat. We also used flexible ducting just before it goes into the unit. Get one with a good quality tank, some have anodes which require maintenance. A better quality one, such as a Joule cylinder does not. Mostly importantly, as its sucking internal air into the system and this will pull cold air from outside. We manage this by having lots of south facing glazing which heats the house for about six months of the year and allows for a bit of this free energy to be sucked up into the system. In the winter we rely on a centrally placed wood burner. Having access to free wood means that I can heat the house, with a few sticks and also the heat from the stove goes into the system. I am in an unique situation and if I did not have endless wood it might not be so attractive. That's not say it can't work efficiently in other circumstances. With the £400 rebate and further expected £200 rebate as a non gas customer, we will have no energy bills for ten months. I don't have any solar panels at the moment, but might get some fitted in the future. Here's my blog if you want to see pictures of the set-up.

Apologies, I seem to have missed this! They are screwed at the very ends only, and are floating for the full length. The screws go through the vertical battens and into the ends of the horizontals, with 2 screws in the pattern of a 2 on a dice. I cut the horizontals a mm or so oversized so they are a nice tight fit, and used 4x80mm screws.

As part of my business I supply and fit lime plasters Clay works is usually descend by the the designers as concrete finish Perhaps worth googling it

It's all one big experiment. And the golden rule of experimenting is change ONE thing at a time. I would start increasing the water flow temperature. Start with say 35 degrees. Let that settle for a couple of days. If your return temperature is not much lower than the flow temperature then you don't have a problem with flow rate. Is the UFH on 24/7 or on a timer? Is it a case of taking too long to get warm, or never getting warm enough?

Thats not the main question - very far from it. The problem is much deeper than that. The key issues here are attitudes to problem solving, and having sufficient humility and emotional intelligence to work with other people: difficult people by your own description. Lets see if I've got this right. Two groups of people, who don't get on with one another, are in dispute about a wall. If nobody does anything at all, over time, the wall will collapse. If nothing is done about that, you will lose some benefit from the land. Now, there is a choice between; Do nothing Argue the matter in the courts Rebuild the wall yourself Rebuild the wall with your neighbour The first choice means everyone loses The second choice means everyone loses and everyone pays a lawyer's mortgage for a month or two. Third: you spend some money and time, probably less than a lawyer's fees. In the third choice, you get a grip of your own emotions, and start to build a relationship with your neighbour. Little steps. Over time. And in maybe a year or two, you might just be able to agree to work on the project together. Maybe even share the cost. Who knows, you might even make another friend. It'll be hard. But you'll be proud of yourself. You'll have achieved something rare. A victory in the fight you have with yourself. For all of us, that fight is the only fight worth having.

Works perfectly for me. One core +24V and the other four for RBGW negative returns. My wiring scheme, fwiw. Random mix! Some cat6a, some cat5e, a couple are even on 8 core security flex. I'm using ESPhome rather than the Loxone 1wire extension fwiw, so if needed can add multiple gateways around the house at very little cost. I used trirated cabinet wire from TLC for must things, but stripped out twisted pairs from cat6a cables for anything using the little pushin wago 243-211 blocks that need solid core. Savvyspaces actually sell tri-rated solid core hookup wire if you want to be completely regs compliant (but the depends what regs your building to, init). I'd probably not bother myself, it's not like the external wires entering the cabinet are tri rated so seems overkill to insist all low current/low power internal wires must be

Ouch! That could inflate your cost / m2

Lol. Twat is a bit harsh, you penis. The other favourite is closing the isolation valves to do the work, and forgetting to reopen them. My least favourite was my neighbour asking if I could see why their combi had suddenly stopped working. Flame failure. Went out to check the flue, and the painter doing the outside had bagged the bloody flue and gone home for the day. Now HE was a real twat.

Funnily enough it ain’t ( according to instructions ) . 2 hangs per main runner . Max there will be 4 main runners - so it’s no problem. The ‘wedge’ fixings into concrete work surprisingly well . I just don’t get how this is held square ( apart from the tiles ) . Still I’ll knock this shit up and we will find out when SWMBO accidentally knocks it and the entire ceiling comes down 👍

Who said that.