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3D print a custom plastic piece to recess it and look neat. You sketch it, I'll print it.

Hi all, just introducing myself as new to the forum but have been on and off the forums for the last few months using the excellent experience and advice to shape my thinking. We are finalising the plans for an extension to our existing house and taking the opportunity to do a big retrofit at the same time to make the place much more comfortable and efficient. I'd really like to post my various thoughts somewhere (UFH, ASHP, insulation, solar, rainwater harvesting etc) to run up the flagpole for people to throw rocks at and really test my ideas before we commit funds.....could anyone suggest the best place to do that? I'm hoping that by getting out of my own head (I'm an engineer....) and using the experience of the forum we can really nail down something that's effective and makes best use of available funds and of course hoping to be able to contribute as well! Cheers!

Back to the question in issue, I discovered today that a as multi purpose lubricant, such as silicone grease, is a must have I in the emergency kit: got home on my bicycle. Went to bike shed, could barely unlock it, certainly couldn’t lock it. Rushed around the house looking for my WD40. Couldn’t find it. Found some silicone grease, bike shed lock working again and bike is safe.

As I have discussed on earlier podcasts and various topics, I have a Willis-based configuration for heating our low energy house, and control is implemented with a dedicated Raspberry Pi using a custom NodeRED application for our underfloor heating and SunAMP-based hot water. This system logs a lot of instrumentation temperatures every half hour and also any significant events such as turning on and off pumps and the heater. Our electricity supplier has been OVO for the last 4 years, and because we have a smart meter, the control application also includes a script to log on to the OVO Portal and download the daily usage data into the MySQL database. Because these latest energy hikes, we have decided to revisit the issue of whether it would now be cost-effective to install an ASHP in order to save on monthly electricity costs for heating. Because I have been logging all relevant data for the past 4 years, I can base this decision on hard actuals rather than some generic planning assumptions. The next two graphs summarise these results. The first is an analysis of our daily energy use (we have an electricity only house). What I have done here is to aggregate the 4 years of data by calendar month and split these into three categories: Underfloor Heating (34% or ~4,000 kWh/yr). In practice, we only heat off-peak and use the thermal mass of the floor slab and the house itself to smooth out the overall background heat levels. As I have discussed in other topics, this results in a temperature ripple of about 1°C which is quite acceptable given the reduction in overall all heating costs. Other Off-peak use (25% or ~2,900 kWh/yr). We also use a couple of small oil-filled electric heaters on the first and second floors for the 4 cold winter months. These output roughly 1 kWh and run on a timer (actually controlled by my home automation system). We find that 3 or 4 hours is typically enough to keep the upstairs acceptably warm in the coldest month; this also means that the UFH on-time doesn't need to run over into peak periods. Our resistive load white goods (the washing machine, dishwasher, SunAmp DHW) are timed to come on in the off-peak period. General Peak Rate use (39% or ~4,500 kWh/yr). Pretty much all of our baseload and direct hands-on devices: fridges, freezers, cooking, computers lighting, etc. Note that the 2 retired (out of the 3) occupants of the house spend most of May, June, September, October abroad; hence the dip in this general use figure. I find the annual variation on this base load a little intriguing ,and I am not sure why it is so high. Our live-in son often has his radiator on in the evenings when he's at home, and we do spend more time indoors in the cold dark months. The simplest ASHP implementation would be for slab heating only and would give a CoP of ~4 (as the circulation temperature is under 35°C) hence saving perhaps 3 mWh p.a. @ 18.86p/kWh or roughly ~£560 p.a. at our currently quoted OVO night rate. Given that we would need to use an MCS certified installer to exploit a permitted development waiver, I would expect our installation to be £10K or higher, so I still don't have a viable cost benefit case to go this route. Yes, adding pre-heat for the SunAmps would increase this annual saving, but this would complicate the installation, and given our volume of DHW use this would in fact worsen the cost benefit case rather than improve it. Another interesting point is raised by the following graph which I pulled from a 2014 Thermal Design post. The bottom line is that thanks to entropy, pretty much all of the electrical energy that we use ultimately ends up as heat within the fabric and airspace of the house. Given this, the overall heat losses (if you take December for example) are pretty much double what we originally estimated. The following can account for the majority of variance, but not all. We had to drop the U-value for the warm roof to minimise ridgeline heights keep the planners happy We added 60° reveals to our fenestration to improve overall light levels given the planners putting hard limits on our window sizes, and these some limited thermal bridging Winter solar gain is almost non-existent for our window configurations. As discussed in an earlier post, we had a cock-up in our slab design which created a thermal bridge between the inner ring beam (this supports the frame) and the outer ring beam (supporting the stone skin). We could only partially mitigate this during slab pour. We estimated that MVHR would have a recovery efficiency of around 90%, but looking at the inlet temp vs room, I estimate the actual recovery is nearer to 80%, that is double the heat loss. We run the internal room temperatures a couple of degrees warmer than initially planned. However the house is built and well established so getting any convergence is now unlikely. So the house performs as a low-energy one, rather than a true zero-energy one. And we still only put ~20kWh into our slab in the coldest months.

I’ve been chatting to our local rep and he’s agreed to reduce K prices Partly the terrible wether over the last few months and suspect mostly The expected downturn Both base and top coat will drop to pre pandemic rates With a little bit of commitment on my part I suspect Webber are reducing also I was watching the news ass the pandemic started They we’re doing a tour of a loo roll factory just a few miles from me The chap stated that while people where hoarding They produced a million per day and had storage capacity for six days I suspect the same will apply to many others

150mm whacked hardcore, 200mm eps/xps, 100mm concrete with ufh pipes in. That’s 450mm to find, from FFL down… If you do decide to keep the suspended timber floor then you will need to carry the ventilation through the slab of the extension and use telescoping vents and air bricks on the footings of the extension to provide the airflow. Or just do what my neighbours did and concrete straight over the existing air bricks 🤣

If it was my house, I'd do both. Comfort temps for the floor vs having to heat the spaces with it ( so UFH just providing some uplift ) and 'decorative' rads providing the grunt.

Rads all the way - unless this is part of a much bigger plan, and you’re installing buffers etc then just go with conventional heating here.

So in my quest for a van (ended up with Ford transit) I was told beware french makes who have had a gear oil change that wasn't oil by the manufacturer. Its inevitably too heavy and it will lay down after 3000 miles. Apparently some people realise after they have done it and sell it on.

You CAN put UFH in this area, but it would be expensive to run eg if this is a basic building regs property ( or worse ). Where the original floor is you could consider oversized radiators there, and then just install UFH in the new area for comfort heating. You can run the overlay system throughout, but it's the very worst type of UFH out there. Another big influencer is what you then lay over it, with tiles being better, wooden flooring being worse.

Buzz has answer your query perfectly. It would be more helpful @Amateur bobif you just told us what your build budget was, we can probably give you a better idea of what is achievable with your budget, and if it is tight, some money saving ideas. I also built to a specific budget and came slightly under TBH.

Fusion 360 seems to be the place to start if new to it all. My lad uses it and is a dab hand. I believe it is getting more restrictive as time goes on, with features being removed. No doubt heading to a fully paid for platform! I still use AutoCAD as I'm old! 😂

Without 120 to 150mm (or more if you can) of PIR under the floor, the heat loss could be pretty large. The boards are 18mm, pipes they are using 12mm, so 6mm of insulation.

We have Fiesta and SMax. I used Forescan software to add cruise control to the Fiesta but while doing that I noticed there appears to be an option to set the mileometer! Although I've not tested it for obvious reasons. If it works it would appear possible to buy a new Fiesta, never get it serviced and after say 2 years 11 months wind back the clock and send it for its first MOT. So a three year old car with just 17k on the clock could have done 50k or more with no or perhaps just one service and it would all look in order on paper.

We have UFH on our first build and will have on our next As with you we would have struggled for locations for rads 153m2 on the ground floor Inexpensive to run Rads ups stairs Though four years after moving in we still haven’t used them

If your floor U value is 0.15 or better UFH is an option, otherwise your downwards heat losses are such that the running cost could be huge. Then radiators is the best solution. Also radiators are better for on off heating, ufh really needs long run times to be viable.

@TerryE Hope Jan has a speedy recovery!

I have an Atag, super quite, especially when doing central heating. I think Viesmann boilers lets you you do two zones at different temps with different compensation curves as well a different temp for the cylinder. I think the way to have a fall back is to have tcvs on the rads, but set them a couple of degrees over your normal room temp. Then balance the system to get the room temps correct. Worst case, you stop weather comp, set up as normal and away you go. An X plan still gives you the ability to run the cylinder at a different or the same temp as CH.

There a few things to get your head around. No need for geofencing or remote control, the basis is the heating runs all the time at as low a practical temp it can. The longer the heating runs the cooler the flow temps can be. You are trying to match heat loss with the amount of heat given from the heating system. What's the point, efficiency - less gas used, due to gas to heat conversion rates above 100%, I am currently running at around 110% efficiency. That means my DHW effectively comes free compared to running mid 90% efficiency. Most heating system run in the high 70s to 80s% efficiency. Solar gain etc. The closer the heat emitter is to the room temperature the more self modulation that occurs. An UFH or radiator system, works by being hotter than the air around it. The bigger the difference in temp the more heat it transfers. The closer the temp the less heat it transfers. The boiler output modulates based on return temperature. So using the above. Room at 20 degs. Sun comes out, room warms up to 23, radiator gives less heat to the room as the delta between to room and radiator has reduced, return temp to boiler doesn't drop as much, as less heat is given to the room, so boiler ramps down its output, because it tries to maintain a set DT between flow and return temp. Radiator is then cooled. Sun goes away room starts to cool, the reverse occurs. It's taken me a year to get to here. But I took all the actuators off the UFH manifold the other day. There were doing nothing, just powered for no good reason.

You need to read the fine print on your local councils terms etc on council tax, they are all different.

@Marvin I think you need a new fridge. I noticed my old one had gone faulty because it was using about 3 kWh/day. A very cheap energy upgrade.

A few pointers, you are working backwards start at ffl and work down with your measurements not up. FFL is internal. FGL finish ground level is external so start at FFL and measure down, you can then work out if you need to add anything, if it was me I would try to add more concrete to the foundation. Then use a concrete trench block not an aircrete one, laid flat so 100mm build up per course, this gives you much more flexibility with height difference. With your one course that comes up so high, if your foundation is 50mm out of level ( it will be) you have no flexibility to adjust the blocks to take up this inaccuracy.

Recess the vent - much the most likely to work and simplest.

Is it an illusion or is the black pipe protruding i trim them all flush to the plasterboard then a vent shouldn’t stick down more than 10-12mm.

only thing I can think of is being wary of the amount of ducting available to move it. I doubt there's any spare to pull it further so you'd have to move it along the length of the ducting.

I chose them because the manufacturer was relatively local to me (Leicester, while I am in Cambridge) so I could visit the showroom and factory in person. And because of the Passivhaus certification of the particular units I purchased suggested good thermal performance. As sometimes occurs in self-building, the delivery of the units had a hiccup, but it was resolved satisfactorily by the manufacturer, and I am happy with rooflights, which are now all installed.

Welcome. Just start asking. The heading is important so that you get the right attention.

If i was contacted with this question I'd be giving the same answers, free, on the phone. If it really is a caravan, not a house in disguise, then prop on slabs or baulks. If it moves, it can be adjusted. If not really a caravan, then it is has to be as a proper submission, or I decline to be involved.

This does seem high, but perhaps it's just a big one or some things were added to be frozen? The sample size is small so could be affected by something like that. I don't monitor mine directly but smart meter data shows it has a background usage of around 365kWh/year. Add a bit for things being put in, door opening etc. Also if you're using a smart plug to monitor I found mine on a dehumidifier was overestimating by 20%, which may go part of the way to explaining it.

Hi @TerryE We have also been looking at energy use figures and its quite interesting comparing how homes work. Our bungalow floor area is 104m2. I monitored the outside temperature hourly using our weather station and compared the results with the local weather station which is only 1 mile away, and sure enough the temperature records were the same so now I just use their data. We measured the daily power demand for as many appliance as possible in our home and keep daily records from when the ASHP was installed. Our average over a day, lowest background power use, is about 300W continual We have east and west facing windows and this gives major solar gain - even during winter on bright days. Our total energy purchased in a year will be about 3400kWh and PV production about 6600kWh so 10k potential. The ASHP uses about 1840kWh a year. The car uses about 640kWh a year These we measured: The MVHR uses about 262kWh a year The fridge freezer uses about 120W an hour or about 1000kWh a year The freezer uses about 550kWh a year. The sky box uses about 280kWh a year The router uses about 130kWh a year. So minimum energy used 2,200kWh a year! Here's a useful link for those who wondered what household item uses what power: https://www.electricalsafetyfirst.org.uk/guidance/safety-around-the-home/home-appliances-ratings/?gclid=CjwKCAiA2L-dBhACEiwAu8Q9YGohisCTL8TQ-HJ_pPVFchK3PdnWzEwFaSzpcjK6f0lcE7iBMI3GPhoCOxIQAvD_BwE Also the more cooking and laundry done in a day the less heating seems to be required! During the winter the the daily non heating use increases but not between 10pm and 8 am so this has to do with equipment use. I noted that the fridge/freezer uses less energy during the winter! Marvin

The only thing I would add, your fan power usage is defined by the Specific fan power, measured in (W/l/s). System pressure drop adds to fan power as the fan runs higher up its curve for a given l/s flow rate. So really introspective of how many MVHR units the same power is used for a given flow rate. In fact if two units reduce the duct length it could be argued a low fan speed is required due to lower system pumping losses. So less watts are used for the same flow rate.

Background run rate on these is about 45Wh so if you said 100Wh in total, then both units running for a week is shy of £6… Will you be turning the fridge / freezer / TVs off standby when you leave the house as those are probably using equal if not more …? And the whole point of background ventilation is that it runs permanently !!

Easiest way to find out is to ask a Structural Engineer, what they do.

I would think several large 40mm+ concrete paving slabs under various structural points would be plenty to share the load. Ensure all are level using a biscuit mix of concrete/sand to help as well.

There isn’t a void, you rip the whole lot up and turn it into a slab floor…. The damp issue is caused by damp in the floor being pushed towards the walls (which are still in contact with the ground)… It might be a non-issue, or it might be an issue. It all depends on what the water table is like where you are. If you end up with two separate systems, a standard screed system in the extension and an overlay system in the old part of the house then you’ll have two separate response times and probably require different flow temperatures.

Hot showers are far more economical (unless you do them @ToughButterCup style🤣). I am a little anal in my technique: I use about 5-10 ltr for a typical shower: a quick wet down; turn off shower and full body lather and rub down; leave lather on for at least 60 sec whilst flannelling; another wet down; flannel off any water and suds; a final slightly longer wet down, flannel off and towel down. Soap + 60sec contact + mechanical rubbing is better than an immersive soak (or just standing under a deluge shower) for getting rid of detritus, and surface bacteria and fungal spores. That being said, Jan took a tumble a couple of weeks back and she managed to crack a rib and tear some muscle and ligaments. Time is the only remedy for this type of fall. The pre-bedtime bath is better for getting a night's sleep during recovery. We've got a water softener and there's very little crap sticking the the bath. I find a quick rub down with a cleaning flanel gets it off.

All the best. Yes it was a long reply.. then main thing is that if you read my post I was not just writing for you really.. it was for everyone on BH.. we all pinch ideas and discuss design be it planning or all the other issues. If you want more help then post more on your thoughts. If you give a bit on BH you'll find that you get much more in return.

I have a sips house, and an insulated foundation from Kore. No brick or block here just a ventilated cavity. You have a sole plate (as do all timber frame houses) then a locator plate, which is just like a sole plate but smaller and allows the sip panel to sit over it and onto the sole plate. You add 200mm high of 25mm pir around the junction between insulated foundation (as per the drgs) and soleplate and Bob's your uncle. This worry about interstitial condensation is overthought. All houses that have a wooden sole plate this applies to. Even if water was to get in and sit at the soleplate or have condensation - it's treated timber.

The wind down legs are just to steady it. My static is up on 8 (albeit should at at least 12) static Jack's. I jacked it up with a standard bottle jack till it was high enough and levelled it. It's on 400mm of type 1, then some wooden pads then the static jacks

It is from time to time Jilly.. like a lot of jobs there is paper work/ compliance. That is less fun. You maybe have the same in you profession.. someone said to me when I was in my twenties.. if you can find a job / something to do that really floats your boat.. that you really get off on for 10 - 15% of you waking day then you are doing pretty OK. We also concluded that if you look back on say a year of your job and you had less than 5% enjoyment then it is not good for your mental health. Time for a change? Now you could say.. hey Gus you are blinkered.. but I spent a big bit of my childhood in Africa, met folk who were into preserving the wildlife.. David Attinbourgh wrote books / referenced them.. but I can tell you that all these folks worked pretty hard and had to do mundane stuff.. just like us in the UK.

Is that because we are not doing it at scale and not measuring the benefits correctly. The rainwater that falls onto my roof and parking area runs directly into the main sewage system, along with the kitchen sink, washing machine, bath, shower and toilet waste. It then flows under the street, collecting all the neighbours waste, into a larger pipe, then gets pumped inland for 6 miles to the treatment plant. Now get this, it then gets pumped 6 miles again, to the sea. I assume that a lot of the road surface water is also being mixed in with the domestic waste water, and probably business waste as well (there is a large laundry company not too far away). Now if I was to collect say 30% of the rain run off from my property and use, directly, 50% of that, that would take fair bit of load of the local sewage system, and would be less pumping. The other 15% (50% of the collected 30%) could be slowly released into the general sewage system, rather than flooded in during high rainfall. This would reduce costs as less pumping and large scale holding would be needed, and hopefully reduce the number of major spillages (we have a lot, Portreath does not smell of seaweed, it is not mud washed into the sea at St. Agnes, and I have stopped telling people in Penzance harbour that it is full of shit, but that is because they park badly and are boring twats, cold water swimmers are the new vegans). So without measuring, and putting a price on those small advantages, it is hard to say if there is genuine saving and any environmental benefits, but one thing is sure, if we carry on developing towns (the preferred option of brown field development) while relying on the same design and management of waste water systems, we are not going to get any advantages at all, just the same 'working on the edge' systems that are known to fail on a regular basis. SUDS was a start, it just needs to be built on and expanded. Southwest Water charge Water £1.9336/m3 Foul, Surface and Highway £3.2938/m3 Fixed charge £54.60/year Thames Water charge Water 149.62p/m3 Foul, Surface and Highway 90.51p/m3 Fixed charge (I can't find this, is there one?) And we all know that Thames Water has a problem with supplying water. Problem my arse, try the South West, we are paying 3.5 times to get rid of the waste and 30% for potable water.

>>> Pretty much everything else eventually heats the house fabric. Yeah, agree. Thanks for the very useful analysis and stats. 11.4 MWh p.a. does sound high. What's the floor area? Since you're obviously a fellow technologist - maybe time for a circuit monitoring set-up?

COP for flow temperatures 35C or below will be over 4 for any reasonable unit. You don't need to MCS heat pumps. You can just slam one in independently and rely on no objections within 4 years to make it defacto permitted. Even fancy ones are well under £5k in the (tiny) size that you'd need. 1000 Vs 4000 kWh/yr. Plus all 4000 kWh on-peak usage moves from silly rate to standard rate. Plus those oil filled radiators die. I wager they're at least 2000 kWh/yr. Night use seems silly high unless that's the direct electric hot water. I've also got a lodger - an IT type with a server that eats 1.2 kWh/day plus a daft desktop PC, and I WFH with many work gadgets running 24/7 plus two fridge freezers (1.2-1.5 kWh per day the pair) and MVHR (0.7 kWh/day) and we just about hit 5 kWh/day (so perhaps 2 overnight rate) with nobody home. Energy monitoring plug time perhaps; to find out what those oil filled rads are really eating?

A drastic, but best performing option is to rip up all the existing floors, level the ground with some hardcore, sand binding, DPM, 300mm EPS, 100mm floated concrete floor with UFH. Marry that to the extension new floor; say 150mm PIR, 100mm screed, so you have consistent floor type, U values, heating loop lengths, levels etc.

In principal you can use beam and block externally. In Scotland you can (in the right circumstances) have B&B over a a raw soil solum.. i.e no DPM with solum screed. They can stand a damp environment. But there is one big caveat. As a bit of background the Champlain Towers South in Florida that collapsed, I think the documentary is on I Player. There is one school of thought. They had a swimming pool and the slab connected into the main structure. They did not realise that the swimming pool slab was "really tied in" so when it failed it pulled the rest of the building with it. If you asked me to design this I would want to play safe and say.. I want you to make sure that the B&B floor / roof is subject to no more a harsh environment that they would be say in a ground floor. In other words it needs to be waterproofed from above. One main reason is that some folk put salt on their drives and patios in winter weather. Folk may get too keen on fertilising pot plants.. again these chemicals can promote corrosion of the steel in the beams. Reinforced concrete can protest and this can lead to failure that will drag the house with it. Yes I know you may not do it (use salt etc) but subsequent owners may be unaware. For all @DeanoFromTheDock is cracking on and has a big chunky retaining wall. Looking at the photo the design looks reasonably balanced as the house is not that wide along the road elevation.. but if it was a little wider then it opens up the possibility to make big savings on the retaining wall. Here you use the house to brace the retaining wall at the top and that can be a game changer in terms of retaining wall cost. Depending on the soil you have and the loads on the ground uphill there is a trick you can deploy. We know for example that some CLAY soils can push quite hard horizontally against a retaining wall. This can be great if you are doing a passive build or eco freindly house. You are probably using EPS ayway so can get a good deal on price. What you do is to dig out more of the soil (if you have the space) and replace with EPS.. this takes out a lot of the lateral soil load, you brace against the house (If you are using ICF walls they can offer great stiff sideways/ horizontal support).. in other words you look at the design holistically and get try and get every bit to work most efficiently. Oh but it sounds like I could sell you chalk from the Downs.. but.. here is a pit fall. If you use this trick you have to be sure about how you are going to control and understand the ground water. EPS floats so you need to check for "ballast".. if not you could wake up one morning and find your EPS is now blocking the view from the windows.. not a good look if you are the designer. @DeanoFromTheDock Let us know what your SE thinks.

What an interesting job, Gus. Your description there reminded me of Jenga. My mantra is ‘take the emergency out of the situation’ . Bleeding for example, just press, hard, if you have to, while you think about what to do. Person/animal can bleed out while you stand there watching. A lot of people unexpectedly freeze. I was once reversing my little lorry and got caught under the corner of the garage roof and lifted it slightly. I realised and stopped, but couldn’t go back or forward. HWMNBO was so incandescent with rage, he couldn’t think, so he just watched as I let tyres down on one side and weighted it with a couple of bales.

Just a quick thought. Got called out to a job a few months back where the structure was unstable. Builder had got some props and so on. The key here was to stop further movement until it could all be examined and understood. The temptation is to make the props tight and whack in bracing tight. This is the wrong thing to do. Nine times out of ten.. put in props and just nip them up. Bracing.. absolute finesse it, just there and no more. If you crank up props and braced hard you can make things worse. A building will do it's best to find alterantive load paths before it falls down. If you start cranking up props hard you can lift the last bits of bearing and that often causes more problems. Most often temporary support is just there to stop things moving more until you can work out the best solution.

You have a very different household to me. At times our 300L tank is barely enough. Our showers can run in excess of 10L per minute so you are expecting a woman with long hair to shower, wash, rinse and condition their hair in 8 minutes. You have not met my wife and daughter. Double that time and water consumption and my 300L tank barely does 2 lady showers, certainly not if it has done 1 much shorter man shower first. Tell them to turn it down to a trickle and they don't see why they have to put up with sub standard. And nearly 2 hours to re heat it "sorry dear you have to wait 2 hours if you want a shower as well" lands you in the dog house. Oh and most ASHP's (probably all) stop heating the house when they heat the hot water. Ours likes to only do DHW in half hour chunks. You can fiddle with parameters to make it do DHW for longer before reverting to space heating.

Interesting figures, I recently looked at this on our house with 13 months of DCC smart meter data compared against heating degree days from a local weather station (https://www.degreedays.net/). Regression fit for input kWh to degree days, input both with and without hot water (some energy lost to the drain). Came out somewhere between 4.1 and 4.7 kWh/hdd. This is a mid 90's house with some insulation everywhere, but nowhere near modern standard and poor airtightness. It'd be interesting to get a range of figures from different types of housing. Also, the point of me doing this is that you can use the average forecast temperature for the following day to work out how many kWh heating will be required the following day, allowing a PV divert to power a heater without over-heating the house. I'm yet to get this set up and am unlikely to bother until export rates drop as my heating is still mains gas.