JohnMo

Depends how thick they are, in Scotland they are specified thicker than in England I believe due to higher wind loads. Our are 8 to 10mm thick. Walk around a 5 or so year old building development near you, to assess what concrete tiles look like, do the same with any slate buildings. Around us the concrete ones tend to have faded and have Moss on them. But that could be our weather etc. (NE Scotland)

Long post. So cold water that feeds the boiler in the loft is taking the easiest route to come out of the cold taps, instead of the more restrictive route into the loft where you have the boiler. Your boiler will not support a UVC as it's a combi. The flow rate may not support more than one shower at a time, unless they have restricted flow. Have a read of the attached to get an idea of what you can do to improve what you have. A plumber will need to jump in on how to balance your flows. Canetis-SuperFlow-Product-Sheet-WE-050318.pdf Combi-SuperFlow-White-Paper-v1-2-4.pdf

Link is about heat exchangers?

Others have done bead insulation, injected into cavity, but not sure if this is an option? dMEV is low on the expense side as you will utilise the existing holes in the walls and wiring. But you don't get the advantage of heat recovery. If you see heat recovery as a must the next thing up would be decentralised MVHR, where a unit takes in fresh air and extracts through the same hole, something like this (quite few different makes are available) is very condition based ventilation. https://ecostream.org.uk/products/

Combi is fine, but if using a combi, look at installing a combi Superflow with it. Have attached some reading material. The other route would be system boiler with UVC. But remember insulation and draft proofing should be your first things to sort out. That will give you the best payback, windows would be much lower on my list of priorities, unless they are single glazed. You should also look at your ventilation strategy. You have possibly got fans that come on wet rooms when you switch on the light, then make a loads of noise for 10 mins. The next thing up is dMEV, always running in the background, but very quietly and very low electrical usage. These fans replace the existing ones, so easy to install. Combi-SuperFlow-White-Paper-v1-2-4.pdf Canetis-SuperFlow-Product-Sheet-WE-050318.pdf

Look up the history of Durisol, they are the first ICF block, been around since the 1940s. There's a good photo on the internet, where a hurricane hit and the only building standing was a Durisol build house.

Mine was supplied by the floor installer, like hollow foam box with a digital gauge. Stuck it to the floor for 24 hours.

Our borehole is in sand, cost s fortune with steel lining, going down 34m

Assume you are on wood stud, large piece of 18mm ply screw to studs at about 150mm centres. Try to spread the load across multiple be studs. Put brackets on ply to hold cylinder etc.

Two factors come mind with cost, are paying someone to do it or doing quite s bit yourself? Have you thought about Durisol blocks, very DIY, quick, you can render directly to it. £2000/m2 is realistic, if you purchase wisely, that could include kitchen and bathroom.

Prices vary so much on a day to day basis, I got a mix of local bathroom showroom ex display and various internet suppliers. You need to shop around. Wolseley, unless your lucky can be super expensive. Also Screwfix and Toolstation can be worth a look.

Be careful, as the humidity level within the substrate needs to be below a given level for the engineered floor. Check with manufacturers instructions. You need a special gauge stuck to the floor to measure the humidity. Our concrete floor even though a year old, the humidity was still too high. I had to use a liquid DPM ( epoxy paint) prior to laying floor.

We are on a borehole, we got a water sample, this was analysed by Scottish Water lab. From the analysis we sorted the filtration. Depends on what the analysis finds, will ultimately determine cost of treatment. We only have a 60L storage, to give the system pump time to catch up with supply, when you open a tap. With the recent power cuts, thinking of upping storage to 200 L.

It may just be the condensate drain, my combi does not have an external connection for a PRV. My instructions explicitly state pipework must be plastic.

But will that affect self builders or corporate builders, that do what they want anyway

You just have to make sure what you purchase is suitable, as some are not flexible enough. You can float engineered flooring with UFH, you just need the correct underlay.

Could you fill the gaps, with a hybrid mastic? But you can get Soudatight LQ for £45 a tub and then go around the perimeter of the house at dpc level and get that airtight also.

You can get down to 0.1 u value, but that is not cheap. General buildings regs u values is cost effective. Basically a SIP, with metal either side instead of wood

I just bought a grout bag from b&q for a few £, like a heavy duty decorating bag you would use for cakes. Only used quickly, seem pretty good.

We are blacked out, been an hour so far. Fourth in 4 days. So back to my question It would be great to have a few lights on and a water lift pump that worked, so we had water etc. Not looking to put on the immersion heater, or kettle, etc, hence the 1kW. Possibly AGM batteries Not looking to power whole house from batteries or PV, just charge the batteries when the sun is out and if required hook up the van to charge the batteries when there is a power cut.

I would go to that specific place on the forum have a good old read, loads of good info. Best thing about UFH, is nothing on the walls. 200mm of PIR insulation in floor, polythene over, clip tubing to insulation, screed over. Design with a free copy of loopcad or get suppliers to do it for you. Once you get your head around it very easy to do. Me and wife did ours.

If it's permitted development, who else is there but the land owner, they ultimately have the responsibility even if they pass the responsibility elsewhere. The council cannot have responsibility, as they may not even know the development is being undertaken. Even with full planning concent needed it still falls on the land owner, doesn't it ?

For context we are between Aberdeen and Inverness, big southwest window, with large roof overhang. Very well insulated, once the heat starts building up, on a still afternoon/evening, even opening the windows has a small effect.

Certainly in Scotland there is no requirement for main powered alarms, but have to be sealed not replaceable battery with 10 year life. Radio linked. CO doesn't need radio link to heat or smoke alarms.

The main problem we got, with a low heat loss house, was heating when it 8 to 10 degs outside and then the demand on the boiler is so low it just stop starts cycles continuosly. We have a thermal store upstream of a combi boiler for diverted solar PV for DHW, this was repurposed to buffer for the 7 loop UFH (winter only), boiler connected to the boiler coil, heats thermal store to 40 deg. UFH takes water from top of thermal store using UFH manifold pump. Works great, no cycling, two port valve at thermal store, controlled by thermostat in hall. Leave manifold pump running 24/7, with Salus self balancing actuators. Controls all the heating in 190m2 house. Don't over think it, if you leave a door open for an hour, the room will be same temp as the rest of the house. Our bedroom doors are always closed, the temp usually below 18, because I have loops designed around around 18 degree room temp, if we leave door open, the temp rises.