Innes-

Thanks. If a large (12-18kw) solar array was installed on the 3 phase supply in the garage would the house need to be 3 phase as well to make full use of the electricity that was generated?

Hi, I like this idea and have been exploring something similar myself recently. I'm wondering what metering would look like in practice? Is it possible to have a 3 phase meter installed but only take one phase in to the house and 3 to the garage? Alternatively if there was a single phase meter on the house supply would there need to be an independent 3 phase meter in the garage?

Thanks. Will get on to the dno. I am now looking at a fronius inverter with victron inverter charger along with the pylontech which i think will allow me to be off / on grid

Thanks for the replies. The hybrid inverter looks interesting. My questions might make it clear that im not an electrician by any means - just learning as i go ! I was advised by an mcs installer that I cant have any more than 4kW of solar panels on a grid tied system without permission. Does any system/product exist that would protect the grid from loads bigger than 4kW flowing back in to it? If not I guess my my choice is between a fully off grid system or getting dno permission for a larger array?

Hi, ive looking at an energy storage system that can operate both on and off grid. I noticed that pylontech seem to have an off grid feature (eps) but im not clear how effective this is for long term off grid use. It seems to be designed for emergency use. Does anyone have any experience of using the eps feature of the pylontech batteries? Also if I attached a large solar array of say 8-10kw to a large capacity battery bank would it be possible to design a system whereby only 4kw of the energy went back in to the grid and the rest was charging the batteries? Alternatively would it be possible to have a system that could be easilly switched between off grid and on grid when more than 4kw was being generated, thus avoiding having to get dno permission for the larger solar array? Thanks

Thanks for all the helpful replies r.e. insulating the dpc. At the rear of the house we have a concrete plinth/step which extends out from the back door. Theres also a reinforced concrete flat roof above linking the house on to a small outbuilding. Will the concrete act as a cold bridge and if so is it possible to calculate how much the overall effect of EWI will be compromised if I leave them in place?

Yes im not even going to attempt using the stuff. From what I was told the Beattie passive system turns the existing exterior walls in to interior walls i.e. wrapping the whole house with a new roof and skin. Mvhr ducting then goes in the new cavity between the old exterior wall and the new exterior wall.

Would there be any benefit in sealing the top of the filled cavity?

Apparently there are several companies out there doing this due to damp issues in some properties. They drill in to the walls and suck it out.

Thanks for all these helpful replies. Glad to hear that there seems to be consensus that I dont need to remove the cwi. The u value info is excellent -thanks. Seems like I just need to try and bring the installer along with me now. I have already had one installer walk away after I said I wanted the dpc done too - he said it was illegal and would never meet building regs! R.e. air tightness I spoke with beattie passive about their retrofits and they were sayign they use passive purple airtight paint on external walls before installing ewi in their 'teacosy' system. Apparently they also put in new exterior walls and a new roof though. Although I am installing an mvhr I have accepted that I may not be able to get passive house levels of airtightness. I plan to use it mainly for improved air quality. Our house is south facing but the installer is saying we need to leave 30mm minimum of sofit to meet the ewi manufacturers requirements. He was a bit unclear about whether this meant 30mm to the gutter or 30mm of overhang. I do wonder if they are being extra cautious because of the 25 year warranty. What insulation will you be installing over the dpc? Our installer is recommending xps with a drip line. Again ive heard conflicting info about whether eps would be better.

Hi I live in Scotland and im currently rennovating a 1950s semi detached bungalow. After many months of reading endless threads on this forum Ive decided to sign up and start posting ! Thanks to everyone who contributes here - its a hive of useful information.

I was hoping this might be the case but the installer seems a bit twitchy about taking the chance on the glasswool. I am looking at £1500+ to get the insulation removed though so I want to be sure its absolutely neccessary to do that.

Thanks for the reply. Cavity construction is pebbledash, 2 rows brick, cavity, brick, plaster. The 300mm is what i measured by removing the kitchen air vent. From what I can tell the insualtion is dry in the cavity but have been advised to drill in to the wall and remove some lower down to be sure. I am in discussion with an installer at the moment about how much ewi to put on there. I have a concrete soffit/overhang of 200mm which i would like to pack out with graphite eps. The installer has advised against this saying it will block light out of my windows. I am not going to move the windows out in to the ewi layer at this stage but may do so when i come to replace them in the future. The installer recommended that i consider up to 140mm eps or go for 80mm phenolic. Their standard install is 90mm eps for a uvalue down to 0.3. He thinks i should aim to meet new build regs of u value around 0.24. Im aiming to get the u value as low as I can.

Hi, I am looking to install EWI on my 1950s semi detatched bungalow. The walls are 300mm with a 50mm cavity. The previous owner had rockwool cavity wall insulation installed around 2012 and I have been advised to get this removed before putting up EWI due to possible damp issues. I wondered if anyone else has fitted EWI over existing cavity wall insulation? I am also planning to install an mvhr and was thinking this would take care of condensation issues that may cause damp. In another forum I read that some folk had sealed up their cavities at the top with foam but this seemed to be controversial. Someone else recommended filling cavities up with a a dry concrete mix. I am feeling a bit confused by it all! Any advice would be gratefully received. Thanks.