http://www.greenbuildingpress.co.uk/article.php?category_id=1&article_id=1126

(But not heated glass.)

Can't find the planning application details here...

http://publicaccess.melton.gov.uk/PALiveSystem77/tdc/DcApplication/application_searchresults.aspx

(It's in the parish of Sproxton.)

Trouble with this classic hopeful method of making beneficial use of solar gain, is that it works fine, prob too well, when you don't need the gain, but fails when you do need it.

In winter, when the sun comes out you can indeed feel the power of even midwinter sun, and you know it's being soaked up by the heavy floor/walls. But what happens when the sun goes in again, as it does in winter - or just when the sun goes down mid afternoon? That warmed floor immediately re-radiates just about all it's collected, back out thro the glass to the cold scenery and sky. It loses heat just as readily as it gains solar input. The only thing resisting that may be selective glass coatings (multiple panes is about conductive loss i.e. irrelevant to the radiant loss I'm mentioning). But sunless time far exceeds sun time in winter, so that's not much help.

SAP etc demonstrates the almost-uselessness of this method, hence the common conclusion that winter solar gain is 'too weak' to be relied upon, hence e.g. Passivhaus's emphasis instead on insulation and airtightness, with solar gain treated more as a summer overheating threat than a winter benefit.

That 'too weak' judgement is entirely to do with the classic, useless way of storing solar gain. That changes when you have a method of moving collected heat away to storage, where it can't immediately re-radiate as soon as collection stops. Passivhaus hasn't realised that - yet - and looks like it won't as it's become a religion.

qeipl... "If the glazed areas are modest"

Title of thread?

Posted By: Joinerqeipl... "If the glazed areas are modest"

Title of thread?

Big room + narrow floor to ceiling window = modest glazing?

FT appeared to be making a general point about winter solar gain.

(have I done enough wriggling yet?)

Posted By: fostertomThat warmed floor immediately re-radiates just about all it's collected, back out thro the glass to the cold scenery and sky. It loses heat just as readily as it gains solar input.

That's just not true. Even plain glass is better at transmitting short wavelength 'solar' infrared than it is at transmitting long wavelength 'thermal' infrared. And as you say, coated glasses improve this discrimination. I think it's highly unlikely that any window in this building won't use high-performance glazing.

Posted By: fostertomPassivhaus's emphasis instead on insulation and airtightness, with solar gain treated more as a summer overheating threat than a winter benefit.

And that's only half-true. You keep doing this with Passivhaus; you really should try using it to see what it actually does. Passivhaus does indeed emphsise insulation and airtightness because it is a standard for the fabric of a house, without bolt-on technology like renewables. But it most certainly does take solar gains into account when assessing the winter heating load. And it does, as you say, also consider the impact of solar gains on summer overheating.

Surely it is possible to have a Passivhaus and still make unbiased judgements!

Posted By: RobinB...........Surely it is possible to have a Passivhaus and still make unbiased judgements!

Maybe not , cognitive dissonance, conflicts with our belief that we always make good well thought out descisions and purchases, even if they prove otherwise.

I agree with djh on this one! A Passive House is a solar house that retains heat for longer!

Posted By: Joiner
Can't find the planning application details here...

http://publicaccess.melton.gov.uk/PALiveSystem77/tdc/DcApplication/application_searchresults.aspx" rel="nofollow" >http://publicaccess.melton.gov.uk/PALiveSystem77/tdc/DcApplication/application_searchresults.aspx

(It's in the parish of Sproxton.)

It's here:
http://publicaccess.melton.gov.uk/PALiveSystem77/tdc/DcApplication/application_detailview.aspx?caseno=LWAXQAKO04B00

Application ref: 11/00954/FUL

Hi Joiner, all coming up for me ok using Google Chrome web browser, they do open as PDFs in a new popup window, might be worth checking you don't have any popup blockers stopping them opening.