Canoehq

Brilliant Neil, seriously, thanks so much !

Thanks. I think that's something I had forgotten. So when SageGlass is fully or near fully tinted and light visibility down in the 17%-5% range, can you still see out reasonably OK ? But apart from the convenience of SageGlass, is there anything else obvious that it might do that good quality solar glass + blinds doesn't ? I guess I'm trying to justify still buying it at 7x the price !! You were a great help btw Neil, so thanks again.

Hi Neil Thanks, yes I did and very grateful to you. But given the SageGlass price and the huge amount I would need, this is a final fact checking exercise I guess, but mixed with a small dose of cold feet ! As I say, I'm simply trying to bottom out what SageGlass would do that a much cheaper solar glass (COOL-LITE 176 for example) with some blinds wouldn't do and how convenient/inconvenient one over the other would be ?

The COOL-LITE SKN 176 has g-value of 0.36 and a light transmission of 70%, so I thought that quite reasonable ?

Thank you again. Just as an aside, do you have any ballpark costs for the roma blinds you've used ? Perhaps per sq m ?

I've taken so many attempts getting this through planning, I'm loathe to go back again and upset them, so your permitted development idea for afterwards might just be utterly brilliant ! Just one bit of advice needed though. So if I have planning permission for 30 windows and I decide to as you say 'have bit more wall and a bit less glass' , is that something the planners are going to pull me up about if I just tweak the design myself to achieve that? I can fully understand it's a no-no to put in windows you haven't got planning permission for, but what about not putting in all of the windows you do have planning for ? What's the protocol, does anyone know ?

Seriously big thank you for such a great reply. Even the best solar glass I can find (St Gobain SKN 176) but at double glazing level still allows about 36% solar gain through (in still being reasonably transparent) and factoring in the cost of blinds on top, I might be heading up towards SageGlass prices, but without the convenience..............eeek ! Pretty obvious that i didn't think of the relationship between reducing solar gain and light transmission and hoping I could have one without the other !! D'oh !

No, pretty strict planning conditions on the barn mean I can't have overhangs / brise soleil type structures for shading unfortunately. I have to minimise the solar gain with glass / blinds etc. Sorry what's PHPP ?

As I say, totally confused with types of glass and going round in circles on this one ! Very, very grateful if someone could put me straight please !!! My project is just about to get underway after the lockdown, but I'm revisiting the type of glass we are thinking about putting in. It's a barn conversion, with the main elevation being south facing and needing approx 100m sq of glass, so yes, that's a lot ! And to prevent it becoming a greenhouse, controlling solar gain is a decision I do need to get right. Parking the relative cost of each product to one side for the moment, I probably just want to get a better understanding of what each type of glass does I guess. The main aim is of course, solar control and having a comfortable temperature inside the house, without it overheating I think I understand what SageGlass does. It is electrochromic, so with a small electric current, varies the tint within the glass to control the amount of solar gain / light that passes through. But it's hugely expensive ! So what is Planitherm 4S (4 Seasons) or Pilkington Activ Sunshade/Suncool, do they basically do exactly the same thing as SageGlass (except that they don't darken) so I would need to factor in the price of blinds on top if I went this cheaper route ? Or does SageGlass do far, far more thna these cheaper products that I perhaps haven't thought of ? As I say, very, confused, but glass companies seem unable to help as they have never heard of SageGlass unfortunately.

@JSHarris Again, that all makes perfect sense. Thank you. @Bitpipe I shall certainly have a look at those blinds, but agree, the internal venetians are not what I'm after i think.

And thank you. So much reading ahead and just as I thought I was starting to swim, I've just gone under water for the first time ! Thanks to everyone so far.

Just a huge thank you for taking the trouble to reply in such detail. Lots to think about. The last figures I spotted on here for sage glass were about £1k per m2 which would be way out of the ball park for me. But if I could find a reasonably priced supplier, then perhaps it could be back on the table. Again, thank you.

Yes and I have an electric car also ! But for 4kw +, it would be way bigger than the 9 sq m allowed for the permitted development install, so back to the planners ..........groan !

What a fantastic forum !

No, just a beautiful open view to the River Stour, so can't complain ! Won't be allowed brise soleil unfortunately, as anything that sticks out over the footprint of the barn is a no-no with the Planners I'm afraid. So, shutters it may have to be. Brilliant idea about the screening, but would hate the interior to become too dark.

@JSHarris I'm intrigued at your last comment and perhaps beginning to fully understand what you meant. May I ask you a quick question ? So in trying to keep things extremely simple so that I can understand them, are you suggesting this comes down to a simple choice between; 1. Hugely expensive Sage glass windows (to keep the solar gain to a minimum); versus 2. Admitting defeat on much of the solar gain and using cheaper standard solar reducing glass but with a PV system running alongside to provide active cooling almost 24/7 if needed ? Is that the nub of it ? My early thoughts are to go with the second option, but we have a very eco-concious planning dept and would hate to upset them with a PV / aircon system running almost day and night !

Thank you again Mr Dreamer !

Hadn't quite thought of it like that and contemplating the high levels of cooling I may actually need if I can't get these windows / glass right. Have had a look at the cost of the Sage glass you suggested and had to sit down ! There must be a cheaper (albeit not simpler) way of dealing with this gain or stopping it entering in the first place. PV may be a good plan indeed, but it can't be roof mounted, as feel sure the planners would not allow.........and it's a round rook also, so may look a bit odd ! Have enough land at the bottom of the garden to install there though and in the middle of what was going to be a conservation wild meadow, bees etc.

Seriously good advice, thank you. Re Solar PV, didn't honestly think the pay back numbers worked for us as we head to retirement in a few years, but will re-visit. Also, never seen such a hike in fees using an MCS installer compared to what a switched on heat engineer and a six month old ASHP would cost me ! Yes, have appointed a project manager who will arrange all of the works and building supplied as needed. Even though he's not VAT registered, if I order directly, that's 5% right ?

Well I know it's not zero rated because not a new build, so had assumed it was the next band up at 5%. Is that right ?

Yes, architect and planners didn't object ! No doubt he was after a design award or something but with little thought as to how someone would live there afterwards ! Yes, an entirely new steel frame being built over the same footprint, with new slab and/or deeper pads as needed. The old stanchions need to be retained apparently, but will be bolted to the new frame and hidden. They will not be load bearing.

There is no slab. Just a dirt floor with the current stanchions on shallow concrete pads.

Good straight advice. Thanks, I like that !

Don't know yet, designs still being finalised, so up for any advice whatsoever that will let me short cut months of mistakes or the dreaded "I wish I'd thought of that earlier" afterwards !

LOL ! All positives so far then ! ........and no, the very last thing I will ever be is upset. Just grateful for the help ! But we have a few months yet getting things and ideas straight before we need to start building, so the more ideas that can be thrown at me, the merrier !