Leaderboard

From the HMRC forum.. https://community.hmrc.gov.uk/customerforums/vat/ebb59f20-6793-ed11-97b0-00155d9c7b3d

I think I can close this now. We have looked at all options - initially decided on steel, got six quotes which were all incredibly high - block was higher still and have eventually settled on a beautiful 4-bay oak framed building which is actually cheaper than either solution. The drawings are being finalised now.

My old fixed tariff was due to expire beginning of Feb, so I moved over to Octopus in anticipation of that, and in order to get rebate payments as I've signed up to Ripples second wind turbine project. I signed up via a link to join the Cosy tariff. Got switched over to Octopus week and a half ago, and was switched onto Cosy on Thursday last week. For our house we have an 8kW heat pump connected to a 300L DHW tank and a 300l buffer to tank for whole house UFH. We've also got 7kW solar, with 14kWh batteries installed last year. So, there was a lot of fiddling and tinkering with settings and timers to try and get the best out of it, and it'll take a few more days/ weeks to get the temps and timing right. But basically, the whole aim is to try and run everything ad charge everything during the 2x3hr cheap slots so we import the least amount of electricity possible at all other times. At the mo, I've got the batteries set to charge to 75% overnight which sees us through the morning and breakfast until 1pm easily enough with a bit of spare capacity for charging if/when the sun shines, and then to 100% by the end of the 1-4pm window, ready to see us through the night until 4am. The heat pump is set to come on during the cheap windows to top up the hot water tanks, and the room thermostats are set to heat the rooms only during the 3hr slots, morning up to 20/21 for bedrooms/other rooms, afternoon up to 21/22deg, so slightly warmer to keep a decent temp until they come back on at 4am. Seems to be working out quite well so far, and I think this tariff really benefits from having batteries which really take advantage of the cheap slots. I think through the year and more solar is produced I'll be able to reduce some of those battery charge levels as more and reliable solar can top them up. Plus, the heating will be off saving muchos kWhs!

Not a chance! My clients all report the towels drying out very quickly, zero damp / dampness, tea-towels drying out quickly in kitchen etc. A good shower will still make the room 'steamy' but then it goes away quickly along with any residual moisture. You have to remember that the airflow is constant throughout the house so nothing gets a chance to loiter about, but this can affected by how thoughtfully the air valves were positioned. Some designers will install next to the doors, which doesn't promote airflow across the whole room as well as placing the valve at the furthest point away from the door does. As with most things; "done poorly = performs poorly", but I've not heard anyone having such issues to date.

I wish i had taken a picture yesterday. Visited the farnborough Self build show on sunday and had a look on the Rega vent stand, they had a cutaway of the MVHR unit. It is very difficult to understand how you can justify charging what they do for what is inside the box. I doubt its only them actually. A plastic heat exchanger unit, some cheap looking fans and what looks like an Arduino to control it all. Oh yes and a plate filter, that must be al of £20

As with bricklaying and plastering 3 and rising Many company will pour around 0

5 degrees usual limit, 3 degrees air temp absolute minimum. Main things are is that the concrete itself is over 5 degrees, the ground isn't frozen, that temperatures are rising when you pour and you have a way to protect the pour from frost. 10:30 is a good target time if the site gets the sun. Blockwork you can start 48 - 72 hours after. If there are points loads should be waiting for at least 7 day cure time. Build plenty of slack into the programme for path critical things...

any photos? Timelapse video? everyone loves to see stuff being smashed up!

As @Temp says well insulated house with UFH heat pump will be cheaper to run. Heat pump give great efficiency if the flow temps are low. The thing with heat pumps the design needs to be well thought through. Your mentality needs to be different from normal gas, as they won't work that way without you needing a second mortgage. Your cylinder needs as big a coil as you can get 3m2 or better. Your run times for UFH or rads need to be long and low temp. Buffers will kill efficiency and so will lots of zones. Done right SCoP of over 4 should be achievable. If you want your heating on a couple of hours in short blasts and lots of zones, then gas maybe a better choice.

Heat pump vs gas boiler... Historically the electricity used to run a heat pump has been three times the cost of mains gas when comparing like to like, however a correctly installed heat pump has a COP of 3 so the running cost should be similar. Heat pumps tend to work better in well insulated houses with UFH. If you are planning levels of insulation much better than the minimum required by building regs I'd probably go with a heat pump. First make sure you can get a decent electrical connection eg 100A. Especially if you want electric showers and a car charger. It's not unreasonable to install a three phase supply in some cases. Edit: Servicing can be more an issue with heat pumps but that should get better. If someone recommends a particular heat pump check there are people in your area that can fix any issues. Try ringing around asking if they can fix a problem on an xyz?

Thank you buddy. No - its not a requirement as far as I'm aware, I've never seen it mentioned. The only reason I flagged it is to mean that there would be no reason for any neighbour to complain about the building - PD or otherwise. Apologies for the scare.

We’re going to use PD for similar. It looks to me like you’ve covered every base, I can’t think of anything you’ve overlooked. I am interested in your comment: That’s not a requirement is it? I sincerely hope not for my sake!

Another vote for genius hub here - I have this tied in to home assistant, so the sensors are also available there

I have a couple of questions (I'm learning): Why 24VDC rather than 48VDC? Where do you get your bulbs? I have seen lots of 24VDC strips, but not bulbs Bulb fittings, I would like to use standard bayonet or threaded bulb fittings 1. LED strips only (?) come in 12V or 24V versions, with 24V the far superior. This is most of the low-voltage lighting, using constant-voltage dimmers. The other items are some accent / marker lights; these are constant current and only have about 3V forward voltage on the diodes so 24V vs 48V is moot (unless putting a LOT of them on one dimmer channel). 2. Yes. 24V CV LED strips, and various 300mA and similar constant current LEDs is small low-level wall marker lights and such like. 3. Good luck!

This is only for initial commissioning - they want to see that the current clamp is seeing import i.e. it's the correct orientation on the supply cable.

As above - Having now lived with MVHR I think you'd have to be mad not to do it. Bathroom does get steamy but clears away relatively quickly. We have a clothes airing rail below a supply vent and most washing will be dry within 12 hours. Generally the environment is pleasant. That combined with steady temperatures as a result of airtightness and decent insulation levels. House is only half finished too - MVHR isn't even setup properly yet!

Do you have room for a horizontal unvented cylinder in an eave space?

Your rooms with 29.16m3/h should that translate to 1.7m/s with 90/78 radial pipe, rather than 1.27m/s

TBH if I was putting additional load on those rafters I would be putting in collar ties and then you get the semi vaulted ceiling by design. You’ll need minimum 100mm between and 35mm over to get close to building regs and may then get away with replacing one or two slates on the hip end with nice lead vents - one at the hip and one high up at the far end should allow airflow and keep BCO satisfied https://www.leadworx.co.uk/shop/lead-roof-vents/lead-flat-top-roof-vents These guys make some lovely stuff..!! Should be a conservation idiots wet dream …

@saveasteadingany chance of a photo of your structure. I’m looking to build something myself & what I’m looking for sound similar to what you did. @puntloos there are lots of systems out there, to keep the feet off the grass, in addition to concrete plinths. threaded rods into concrete for example. Screwpiles. Zoology is not my specialist subject but I would have thought appropriate planting around such a structure etc to encourage animals and birds would be the way, and I suspect there is a lots of websites out there advising best way to attract certain wildlife.

The big challenge you’re going to have us getting sufficient light in to the original part of the house, followed by the aesthetics of an already extended house, plus the reduction in size of what sounds like a modest sized garden. A tricky combination to get right. Popping on an extension could even make your house worse if done poorly, we’ve probably all viewed over extended houses before. plans are inevitably 2D, buildings are 3D so you’ll probably have to post images for us to offer ideas, or alternatively consult with an architect. Another research tip is to find similar houses with extensions in your area, then have a look at their planning drawings to give you ideas.. If you want members here to give up their own time to offer you free and best advice, we can only really do so could you please commit provide far more information namely: budget spec/style site plan even a sketch or google maps image. photos of rear of house and existing space lifestyle, family, circumstances and wish list other than “bigger”. Kids, dogs, disabilities as all are relevant an interrelated to any design. For example ideas for a couple in their 70s who love cooking and host dinner parties with a budget of £100k, are likely to be different than say a young couple who hate gardening but enjoy BBQs and have a budget of £50k.

I cannot see any advantage in this LV idea. If it is to save money, buy one less device, or cut showering time by 10 seconds. 8 Copper has an embodied energy between 30 and 90 MJ/kg. Taking the lowest EE and assuming you put in 5 kg of copper, that is 42 kWh. Now my phone has a 5 AH battery. So 0.025 kWh. Or, before system losses, I would have to charge it 1700 hours to pay back the energy debt, that is about 2.5 months. I doubt it has had that much charging in its, so far, 4 year life.

Thinking is overrated. If I said/typed what I was thinking, I would be in prison, frequently.