Iceverge

Pump the cavity with closed cell foam. Insulation and airtightness in one shot You could drill from the outside to align the airbricks and put in ducting to maintain ventilation. Polyurethane foam won't degrade the plasticiser in the wires, although I think this risk of EPS beads is large theoretical. Similarly cable heating. A relation of mine did their cavity about 10 years ago. Plenty of wires in there and no ill effects.

Sorry, I was wondering what the total outside area of the building was. The total of the ground floor slab, walls and roof and ceiling. This can make a big difference as a bungalow will have more walls and floor and ceiling exposed to the cold than a two or three story of the same floor area.

That's a shocking suggestion

Passive House here in the south west of Ireland. Our heating in the last 2 weeks has averaged 20kWh per day for 185m2. Direct electric no heat pump. Just a single 1250w radiator on an inbuilt thermostat downstairs in the utility. It comes on at about 5pm and goes off at 8am. This equates to about 4.5w/m2 but the house is closer to 18-19 deg at night. This is fine apart from when you're sitting watching TV for a period or get out of the shower when it can be chilly. I might experiment with a fan heater in the bathroom if I get a chance. @Moggaman are you running a stove too? What airtightness reading did you get? What is the overall surface area of the house?

Can you replace with a PVC coated steel roof? https://www.gusclad.ie/products/standing-seam-profile/

Sadly yes. I built a slurry pit last year, covered by slats so no falling in hopefully. As I was in the 3m deep excavated hole discussing something manly and concretish with the contractor I spotted a lone frog hopping around forelonely. I picked it up just as my surly concrete man accosted me and mounted a bloody robust verbal defence of the frog. He relaxed and smiled when I told him I was going to put it back out on the grass. He thought I had murderous intent. Not all of us are bad I'd like to think. The system unfortunately encourages maximum production with scant regard for the rest of the living world. @Kelvin roofs are terribly dangerous. In the last 18 months 2 men have been killed in separate falls from shed roofs near me. Very sad.

Have you seen when farmers start building stuff? Had they been working on the pyramids they'd be thrown off site or some of the carry you'd witness.

It makes the perfect garage to store a pushchair.

You could conduct a small controlled test. Or buy some Borax and recoat it in it. There's an American on youtube (there always is!) who has done masses of construction with aircrete and recycled EPS he collects from furniture stores Made an EPS shredder from an upturned Flymo and a barrel. He uses a leaf vacuum to blow the beads loose into various voids.

How about shredding graphite EPS sheets yourself if it's only 1m3.

Why not call back the guys who did the walls and get them to pump the stacks?

BUILD edqdwdwded your own rig. Ingredients. 1. A sheet of OSB. 2. A scrap car radiator fan. 3. Some screws. 4. Some duct tape or similar. 5. A length of wire and crocodile clips. 6. A length of electrical conduit 7. A candle that will slot into the conduit. Total cost < £100. Method. 1. Measure an opening ( outward preferably) window sash and cut the OSB to the same size so it slots in against the seal in place of the sash. 2. Cut a suitable hole and screw the car radiator fan into place in the OSB. 3. Tape the OSB and fan to ensure no leaks in the window. 4. Use the wire + crocodile clips to connect the fan to your car battery. (Leave the car running to avoid a flat battery) 5. Ensure the fan is pulling air out of the house. ( You can reverse the fan or swap polarity on the battery if you get it wrong) 6. Go room by room with the back of your hand (big leaks) and the candle in the conduit ( small leaks) and seal each and every tiny hole with proper expanding foam or age proof flexible sealant.

Can you log onto your local council website and have a gander at the recent planning applications. In Cork all of them are on there since 2011, I don't know about other counties. Find a similar sites and have a look for applications sent back for revision for being too tall. It should give you a good idea of the ridge height you're allowed. Broadly single story ~ 6m Story and a half ~ 7m Two story ~8 m ridge heights is the code they use in Cork. Either way, even with 6m you can have a room upstairs.

Here's the rough work if you like anything ( or can see it ) I'll post it up.

A reduction to 227m2. I did away with the upper level. I've tried to keep all the existing rooms, upped the external walls to 500mm. Light to arrive in the north side via sky lights. I haven't drawn them. Please query if anything in the picture doesn't make sense.

The nation grid seem to think the UK will be ok. Similar point to what @George made. I hadn't considered that refining fossil fuels uses a non inconsequential amount of electricity that would be liberated too.

The enforcement of the building regs is quite hit and miss. We are all electric here. Just a plug-in rad. Time over again I'd probably put in UFH just so I could bank the heat like @TerryE on overnight electricity. It depends on your engineer but if you just "haven't gotten round" to getting the ASHP installed they may still be willing to sign off the house. It depends on the individual. If you log into HebHomes they have a selection of nice longhouse designs but I'm unsure if they deal with Ireland. Might be useful for ideas however. The design in nice to be fair but I would worry it'll be expensive to build and run. Also a round trip of 60m odd to the fridge from the master bedroom might become tiresome.

@beebeeQuick sums here, hope you don't mind. You have a surface area at the moment of about 1000m2, very roughly double ours. At part L backstop you will have an average U-Value of 0.27 and ball parking from our own build you will use 10,000 kWh of electricity per year on heating. @22c per unit and an air source heat pump with a coefficient of performance of 3 that will be about €730 per year in heating costs. If you were to increase to passivhouse levels of insulation which in, you case would be an average U value of about 0.12-0.13 including windows you could half that bill. Bear in mind to reach those levels you'd need to be well below 0.1 on the walls, floor and roof to get those overall levels of insulation. Now take an alternative scenario. I realise (too late of course!) that out house for 2 adults + 2 kiddos at 186m2 is probably too large. There's a lot of space taken up storing stuff that could easily be put in a shed. A house at €1500-2000/m2 is a very expensive storage area. Time over again I would. 1. Bore a well. 2. Install a 40ft high cube container adjacent. 3. Bring out Electricity supply to the container and set up a water supply here. Then the container could be used for storage during the build and if clad suitably used for a dry secure storage area once we'd have moved in. 30m2 of storage would cost at most €150/m2 which in turn could chop €40,0000 off the size and budget of the house. With a bit of rationalisation of the design you could get down to 200m2 then quite easily. Make it a dormer or a story and a half and you'd lightly be down to about 600m2 of external surface area. A little work on the airtightness and insulation and windows and you'd be looking at a heating bill of probably €300/year and 60% of the cost of the structure. Mind you I do like bedrooms on the ground floor. I miss the proximity of our previous 60m2 rental cottage. Bed to breakfast table time was probably about 5 seconds!

Fáilte from another in the Emerald Isle. We had a budget of €300k but had the site already. We had a builders finish quote of €216k. We spent every remaining last cent on everything else and I still did a year of work on it during covid. That design is bananas. Miles of external wall which are expensive to build and heat with a bit of thought you can have a much squarer design that works well. Out house took 19 month to move in with a builder.

Still at it. It's slow progress, waiting for taps ATM. Gottya. I was wondering about this. Its happening by necessity anyway due to the location of the cylinder. The install diagram is now the same as the first one too except the draw off diagram.

This might be noisy at 55%. I'd buy a bigger unit. 30% at trickle is plenty. No experience of Nuaire. Have you priced filters? Some brands can be expensive.

€100/m3 2 yes ago for us inc vat.

They're heat pumps but only heat the air directly rather than water, sometimes called A2A on here. They're fast response, cheap, offer excellent heating and cooling performance if you pick the right model. Where space heating is the bulk of the energy requirement they make a lot of sense. They're in almost every commercially building. The cardboard cathedral in Christchurch NZ I quite liked. Made from cardboard tubes and double walled polycarbonate post the earthquake. I second the call for a proper "passivhaus"professional. Otherwise you may struggle to keep overheating etc under wraps. With Sustainability in mind I had 2 thoughts. 1. A safe secure and dry bike storage area. 2. An area for breast feeding, nappy changing and kids + parents.

What an interesting project. I'm guessing it's circa 300m2 internally so not drastically different from a large house. I second the notion of rapid response heating. If UFH you'll be best to do it in as thin a screed as possible with closely spaced pipes. However I think a multi split air to air unit would be more than sufficient. A good brand should be near silent as well as keeping the building cool in hot weather. Aim for excellent airtightness and install an on demand MVHR unit and the building will never get too cold. For the kitchen an undersink water heater on a timer would be economical. Given the intermittent occupation and very low water demand almost all solar power will go unused if off grid. I would completely isolate the ideas of power generation and usage because unlike an office or house there'll be tiny overlap. If aiming for the lowest environmental impact using materials with low embodied energy is important. If you build just from things that used to be plants you won't go far wrong.

Weed membrane for the purpose of keeping weeds down and the gravel to help protect the membrane and prevent any splashback on the timber. A mini french drain will keep the localised water table from pooling under the structure in times of heavy rain. The highest lightlyhood of decay is the metal wood interface where condensation will form in cold weather on the ground screws. You must ensure this is very free draining. I'd consider a "shoe" of a more durable hardwood or plastic to sit the softwood joist on to ensure theres no risk of condensation forming and pooling where the softwood will be sitting in water. I'd be interested in other people's take on it. I hate plastic DPMs under sole plates etc. It only traps moisture as far as I can see.