Totally confused re SageGlass vs others

[Canoehq]

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.

Edited August 3, 2020 by Canoehq

[Dan F]

Before looking at glass options, have you:

1) Built in any overhangs and/or modelled the design in something like Sketchup that will allow you to design a south-facing elevation that avoids direct sun during the summer?

2) Done any modelling to understand how much a overheating problem you might have e.g. PHPP? (model can also be used to test different solutions)

 

14 minutes ago, Canoehq said:

so I would need to factor in the price of blinds on top if I went this cheaper route ? 

It all depends on how much you need to reduce solar gain, which will depend on orientation, tree shading and overhangs etc.  Solar glass itself with a low g-value might be enough, but it might not be.

[Canoehq]

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 ?  

[Dreadnaught]

4 minutes ago, Canoehq said:

Sorry what's PHPP ?

 

Its a spreadsheet used for Passive Houses. More details here: https://passivehouse.com/04_phpp/04_phpp.htm

 

And perhaps slightly more approachable here: https://passipedia.org/planning/calculating_energy_efficiency/phpp_-_the_passive_house_planning_package

Edited August 3, 2020 by Dreadnaught

[Mr Punter]

Can't you have a bit more wall and a bit less glass?  100m2 is a lot.  You will probably suffer glare, overheating and unpleasant acoustics, as well as the poor insulation values.

 

Bear in mind that if you are outside of conservation area and not listed, you may be able to have external shutters / shading after the development is completed as permitted development.

[Dan F]

 

4 minutes ago, Canoehq said:

pretty strict planning conditions on the barn mean I can't have overhangs / brise soleil type structures for shading unfortunately.

 

So you are right to be looking at solar glass, blinds and SageGlass!   My guess is that blinds or SageGlass would probably be sufficient on their own. Solar glass might not be, unless you went for a 0.23 g-value variant maybe, but that would impact light-transmittence fairly significantly which might not be ideal in winter.

 

Quick look at some of the spec sheets:

- Good blinds will reduce solar gain by 70%+ and can be raised/lowered/tilted.

- SageGlass will reduce solar gain by 25% all-year (which may be beneficial given amount of glass), and up to 95% when activated.  (25%, 70%, 80% or 95% by the look of it) https://www.sageglass.com/sites/default/files/sageglass_datasheet_climatop_42.1ec-12-4-12-4_classic_en.pdf

- Solar glass will reduce solar gain by  25%-55% depending which coating you get.  The more reduction in solar gain, the lower the light tranmission. Can't be adjusted.

 

(all vs. standard 0.5 g-value for triple-glazing)

 

On the forum there are people that have used/using both options: blinds (me and others) and  SageGlass too (@NSS)

 

[Canoehq]

11 minutes ago, Dan F said:

 

 

So you are right to be looking at solar glass, blinds and SageGlass!   My guess is that blinds or SageGlass would probably be sufficient on their own. Solar glass might not be, unless you went for a 0.23 g-value variant maybe, but that would impact light-transmittence fairly significantly which might not be ideal in winter.

 

Quick look at some of the spec sheets:

- Good blinds will reduce solar gain by 70%+ and can be raised/lowered/tilted.

- SageGlass will reduce solar gain by 25% all-year (which may be beneficial given amount of glass), and up to 95% when activated.  (25%, 70%, 80% or 95% by the look of it) https://www.sageglass.com/sites/default/files/sageglass_datasheet_climatop_42.1ec-12-4-12-4_classic_en.pdf

- Solar glass will reduce solar gain by  25%-55% depending which coating you get.  The more reduction in solar gain, the lower the light tranmission. Can't be adjusted.

 

(all vs. standard 0.5 g-value for triple-glazing)

 

On the forum there are people that have used/using both options: blinds (me and others) and  SageGlass too (@NSS)

 

 

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 !

Edited August 3, 2020 by Canoehq

[Dan F]

COOL-LITE SKN 144 II has 0.23 g-value (vs. typical 0.5 for no coating) but light transmittance is reduced to 41% (vs more normal 70% with no coating).  Given the amount of glazing though 0.23 g-value might not be enough to stop overheating, very hard to know without modelling it.

 

If I was in your position I would:

1) Look at overhangs and/or reducing glass as @Mr Punter pointed out.

2) If I couldn't do either of those, I'd probably want to model it to ensure whatever I did was going to work, as if it didn't it'd be a major discomfort (using PHPP probably).

3) I'd personally probably go down the blinds route (we are using roma.eu blinds), but given how much glass you have you might want to consider using some solar glass too...

 

SageGlass is conveient in a different way to blinds, I'm unsure on the relative prices though. If you do look at blinds, if possible try to order windows/blinds together to save headaches.

[Canoehq]

16 minutes ago, Mr Punter said:

Can't you have a bit more wall and a bit less glass?  100m2 is a lot.  You will probably suffer glare, overheating and unpleasant acoustics, as well as the poor insulation values.

 

Bear in mind that if you are outside of conservation area and not listed, you may be able to have external shutters / shading after the development is completed as permitted development.

 

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 ?

[Dan F]

Sorry, my numbers aren't quite right as the solar glass numbers I was looking at were double-glazed, not triple-glazed (sorry).  So would be bit lower than 25-55%.  I'd get the actual numbers but seems calumenlive.com isn't quite working...

[Canoehq]

Just now, Dan F said:

Sorry, my numbers aren't quite right as the solar glass numbers I was looking at were double-glazed, not triple-glazed (sorry).  So would be bit lower than 25-55%.  I'd get the actual numbers but seems calumenlive.com isn't quite working...

 

Thank you again.

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

[Dan F]

2 minutes ago, Canoehq said:

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 ?

 

I think it will come down to local planners and if you have any neighbours that might notice and or complain.  The advice our architect gave us was:

- Can't add windows (we didn't discuss removing windows, but I guess it depends if/how they impact overall look/street scene etc.)

- Can adjust windows size/position sightly within reason with no issue.

 

Others might have have different experiences though..

 

[Dan F]

2 minutes ago, Canoehq said:

Thank you again.

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

 

Added about 40% on top of our windows price I think, but we put blinds on 80% of windows. Problem with Roma is you can only buy them along with one window brand, they don't resell in UK.  The only two options I found with UK-reseller for windows/blinds packge was Internorm + Gaulhofer.  Warema blinds are also very good, and there are a couple of UK suppliers if you wanted to do windows/blinds separately.

[Canoehq]

23 minutes ago, Dan F said:

COOL-LITE SKN 144 II has 0.23 g-value (vs. typical 0.5 for no coating) but light transmittance is reduced to 41% (vs more normal 70% with no coating).  Given the amount of glazing though 0.23 g-value might not be enough to stop overheating, very hard to know without modelling it.

 

If I was in your position I would:

1) Look at overhangs and/or reducing glass as @Mr Punter pointed out.

2) If I couldn't do either of those, I'd probably want to model it to ensure whatever I did was going to work, as if it didn't it'd be a major discomfort (using PHPP probably).

3) I'd personally probably go down the blinds route (we are using roma.eu blinds), but given how much glass you have you might want to consider using some solar glass too...

 

SageGlass is conveient in a different way to blinds, I'm unsure on the relative prices though. If you do look at blinds, if possible try to order windows/blinds together to save headaches.

 

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

[Dan F]

9 minutes ago, Canoehq said:

 

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

 

 Yes, with so much glazing it's hard to know if it'll be enough to prevent over-heating though!!   0.36 g-value in 100m2 glazing is 10x 0.36 g-value in 10m2 glazing!

[NSS]

2 hours ago, Canoehq said:

As I say, very, confused,  but glass companies seem unable to help as they have never heard of SageGlass unfortunately.

 

Did you have a conversation with SageGlass after I put you in touch previously?

 

[Canoehq]

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 ?

[NSS]

9 minutes ago, Canoehq said:

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 ?

 

Okay, just wanted to check they'd actually got back to you ?

 

Can't really add much to what @Dan F has said, but don't lose sight (if you'll pardon the pun) that one of the main benefits of SageGlass is that you can still see out when fully tinted. Shame to ruin all those views with blinds imho, but it's your project and I as I said before, that's a heck of a lot of glass!

[Canoehq]

6 minutes ago, NSS said:

 

Okay, just wanted to check they'd actually got back to you ?

 

Can't really add much to what @Dan F has said, but don't lose sight (if you'll pardon the pun) that one of the main benefits of SageGlass is that you can still see out when fully tinted. Shame to ruin all those views with blinds imho, but it's your project and I as I said before, that's a heck of a lot of glass!

 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.

[Ferdinand]

On topic: I think this will make you very popular with Sageglass Inc ? .

 

Can I ask another totally .. er .. ontopic question of our tinted glazing expert (*)? (Berry picking exhibition in Derbyshire later this week).

 

Do blue tinted sunglasses make blackberries easier to see amongst the leaves?

 

Ferdinand

 

* This is the defined as the person who can answer my question.

Edited August 3, 2020 by Ferdinand

[A_L]

22 minutes ago, Ferdinand said:

Do blue tinted sunglasses make blackberries easier to see amongst the leaves?

 

I vote NO. Leaves are green because they absorb blue and red light and reflect green. The green is absorbed (along with any red) by the blue lenses so (relatively) no light (black) gets through making the leaves darker and more similar to the fruit

[Ferdinand]

1 minute ago, A_L said:

 

I vote NO. Leaves are green because they absorb blue and red light and reflect green. The green is absorbed (along with any red) by the blue lenses so (relatively) no light (black) gets through making the leaves darker and more similar to the fruit

 

I'll let you know at the weekend ?

[NSS]

1 hour ago, Canoehq said:

 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.

 

I'll take some pics tomorrow (too late now) of the view out at various degrees of tint so you can see for yourself. The other point, and I don't know whether it's relevant in your case, but when tinted you cannot see in during the daytime. It's like looking at a black mirror from outside, which gives daytime privacy if you're overlooked or have a footpath running past your house for example.

Edited August 3, 2020 by NSS

[NSS]

View out - SageGlass clear

 

[NSS]

View out - Level 1 tint