Conor

I was in a similar situation when building my brewshed. I spoke to my BC officer about it, and because it was classified as an outbuilding and not habitable space, he didn't care about it and wouldn't fall under his remit. Just said it would be installed to the appropriate standard by a competent person. I ended up extending an existing RCD ring circuit from an external socket at the back of the house. Used armoured cable and buried under the deck and lawn out to the brewshed. Couple sockets and a fused spur for a 5a lighting circuit. All works well, no issues. My neighbour who's a spark okayed it.

Speak to Kore. I'm 1.5hrs drive from their factory in Cavan, so transportation costs are minimal. But I have heard they are still competitive in the UK market. From my interactions with them, I'm impressed with their service.

I've done some digging. For a 100m² slab you are talking in the region of £35m² for insulation forms, delivery and design. For your hardcore, binding, DPM/ tanking, mesh, rebar, concrete & floating, you are talking £75/m², excluding initial groundworks. Remember you'll have less excavation, disposal and concrete costs compared to traditional founds. And you've no need for a secondary screed layer. (Northern Ireland costs)

The drawing shows the proposed dwelling being attached to the existing neighbouring dwelling? If you are considering a basement, proximity to existing buildings may be an issue, depending on soil conditions, your neighbour's attitude and planning policy regarding substructures. In regards to geotechnical investigations, you'll be wanting to drill bore holes to 50% beyond the bottom of the proposed basement. E.g 4.5m for single level basement. Geological Survey online maps will give you an idea of local ground conditions. They also have borehole logs, if luck you might find some that were done nearby. Basement construction costs start at approx double the going rate for ground level construction. E.g. if local rate is £2k/m², then budget £4k/m² for basement. Adverse ground conditions could potentially double or triple that number. We're doing a basement as well... But have advantage of a sloping site so will be a lot easier.

There's a standard way to price up a build - everything is categorised and you don't need to breakdown in to components e.g. there will be a line for internal carpentry, floor, electrical etc. Can't think of where it comes from but may be RICS. Have a search.

We got a rough cost estimate from a QS using our planning drawings. Not sent it to Ecology yet but they've said that they will accept it. I'm detailing it out a bit more by getting quotes for supply and fit items... Like floor slab, ICF, windows, heating system etc. Don't need full detailed drawings for those estimates at this stage. Everything else is basically assumed.

The NRV won't interfere in the operation of the pump as long the static pressure in the system is enough to open the NRV and start flow when you open the shower valve. You normally only need an NRV if there is a risk of water flowing back up in a system of there is a pressure imbalance or syphoning.

The reason you use glass fibre or mineral wool in a loft is because it's breathable. In most houses you have a fair bit of warm, most air entering the loft space. It has to get out or you'll have damp problems. Squeezing rigid insulation between joists will trap air and cause water to condense on the surface, eventually causing rot and mould problems. Mineral wool is ok, I recommend a full set of overalls and tape up the gloves to the sleeves. And it'll only take a couple hours to get the job done.

For a long period of time when we were still working on our plans, we basically took a laser measure wherever we went. Covertly measuring friends bedroom was particularly fun.

Cheers. Might be best skipping the EWI fixing. Looks like Amvic ICF? Did you get the 100mm EPS panels from them also?

A laser measure is great at getting the dimensions of a room, little else.

Apologies, thought the temp required for legionella was closer to 60c. Agree that gas is currently cheaper than ASHP but it will change bin the future, and as heat pumps are an emerging technology, I see them becoming cheaper, more reliable and more efficient in the next few years. On our tight budget gas is the preference. If we go gas, I'll make sure we can change to a heat pump easily in the future. Not finalised, but sitting at 85B before we add in PV. (Min we need for Ecology mortgage) I'm not really worried about SAP, as they bare little resemblance to actual real world running costs.

Mains gas seems to be more cost effective than ASHP. I'm in the same position and undecided, tho leaning to gas as it's a cheaper capital investment. Long term, running costs seem to be similar. You also have to consider hot water production. ASHPs have lower COPs if you want to heat water to a useable temperature. I'm sure somebody else can explain better than me. Gas is ideal for heating hot water to 60c. But you also have the environmental aspect... Gas is still burning fossil files and always will... But with a heat pump you can theoretically run on 100% renewable energy.

Good to rear the positive reviews on Ecology. They are pretty much the only company that will deal with us, very positive initial feedback from them so hopefully all goes well.

Definitely, more and more people are using them. Think it also helps that Kore are little over an hour's drive from me so delivery is cheap. Also quarry materials in NI are a good bit cheaper than the UK average. Stone quarry 3 miles from my house and concrete yard about 10miles.

I've calculated the other costs - hardcore, binding layer, tanking membrane, rebar, labourer for 1 day, and concrete and it comes out at £9405. Not accounted for soil pipes, power floating or UFH yet. That'll add another £1000 I'd guess. So give or take, a passive insulated raft comes out at about £100/m² installed. Savings over traditional strip foundations come from the reduced excavation and disposal, no secondary screed, and labour costs for not having to build up footings. Not done a comparison yet.

Almost exactly the same size as my floor area. Got a quote for £4k for insulated forms delivered, and engineering fees Inc

Basically you need to build over the pipe with a structure that will take the full loading of the wall above. Normally, this would be a couple concrete lintils resting on pad stones. In your case this will be more difficult as you have limited working room. Good option would be a steel sleeve over the pipe, then encase in concrete. Best practice would be to cut the sewer pipe and slide the new duct over the pipe and make sure the base of the duct is resting on something firm along its loaded length.

That's what I ended up doing when we realised there wouldn't be enough resin to do the roof in one go. Spread out what we had remaining in order to waterproof the roof. Then went back a second time to complete the job Just need to lightly rub down the base before putting the GRP down. Also need to take the join with the previous cured sheet.

From quotes we've been getting, aluclad and aluminium are approx double the cost of PVC. We're going for a mix of the systems - pvc at front and gables, aluminium for the large windows and sliders at rear. Brings cost down from £30k to £20k. Edit, these are for triple glazed, passive certified systems.

Hi @Stones a few questions about your additional insulation sheets. Why were the panels for the rendered sections drilled in to the conc core and not just the webs within the ICF blocks? Also, do you think it would be feasible to fit the EWI sheets to the ICF BEFORE the concrete is poured? I'm thinking it might help with stability and bracing during the pour. Thanks.

Yes, planning angled reveals. Trim off EPS at 45degrees around the windows. Similar detail to the existing Edwardian townhouses further down our street.

Passive, so U value of 0.15 or lower. I'm looking at exactly that option. Standard ICF will 100mm EPS. I've just to understand how you can attach the EPS sheets to the ICF. Thinking a bead of low expansion foam plus a few mechanical fixings of some sort. I remember pricing it up a while back and the cost saving is in the region of a few thousand pounds!!

@scottishjohn spot on. Was using 1.5-2% and was just going off too fast. Used 1% for the top coat and was much better. I'd also suggest you have loads and loads of spare buckets, mixing paddles, gloves etc... It's very messy and brushes etc are one time use. And have extra tubs of resin and catalyst... Better to have too many and have to return to shop than not enough just when you get to your last sheet...

I've only experience with GRP. When it goes well, it's great. But tbh I had loads, and loads of issues. First sheets went down in cold weather... Resin too viscous and then ran out. Next time, it was quite sunny and warm.... Resin started going off too soon. Went lumpy and ended up having to bring a lot of it down. And last attempt was in the evening in perfect conditions. Went well. And to cap it off, when I did the final part of the top coat, left it too late in the day. Got cool and a heavy dew descended before the resin fully dried, so left a white, dusty sheen to to. At least it was only a shed! I'd use it again, as I know what to expect, as it's cost effective, and one on its bloody solid and I can't see it failing or leaking in my lifetime. But I can see the advantage of being able to use a product and not having to worry about a light shower, or getting catalyst mix right. You can see the light dusting on the RHS. Still, happy enough with it despite the multiple mess-ups!