Replacing aluminium windows with timber sash windows

I’m pretty sure those are the original proportions, Graham. Our house is nowhere near as grand as the one you kindly posted a photo of (either Vesey or de Vesci something or other?). Peter Pearson describes our terrace as being “unremarkable” or “rather plain” (I can’t remember which) in one of his books! But there are quite a few terraces in Dun Laoghaire that are similarly plain – at least from the outside.

The windows on the first and second storeys are one-over-one, mostly with their original (and lovely) wavy glass. I know it is early for such large sheets of glass, but I think our terrace was very “modern” in its time. Perhaps the basement windows weren’t one-on-one, but those that I can see across the road are (in a slightly later terrace).

You say: the “latest methods in double-glazed sash construction are effective and generally very accurate and attractive” (and I take note of your provisos about conservationists). But where would one find such things?

@Graham Hickey wrote:

Hmmm – that sounds a bit suspect Echium. Openings with those proportions could have been formed when the aluminiums were installed in the 1970s, thought yes it is possible that they are original: basements often had rather squat windows. Either way though, they most certainly would not have been one-over-ones originally – 1838 is too early for such expansive glass sheets in Ireland, especially in basement windows!
Then again you could be referring to later window frames from c1900 that you wish to replicate – perhaps you could elaborate.

The latest methods in double-glazed sash construction are effective and generally very accurate and attractive, though may not appeal to the most finiky of conservationists :). For basement windows though, I’d deem them more than acceptable.

Though rather grand, here’s an 1840s Dun Laoghaire house with Georgian grids, incl the basement:

Morning, Graham!

Thanks for your interest. When I say that my house is modest, I mean in comparison to the one you depicted. It is relatively large, by today’s standards. 2 storeys over basement, double fronted, and about 2,500 – 3,000 square feet. Would have been a well-to-do draper’s house or a young doctor’s. That sort of thing. The date, 1838, comes from one of Peter Pearson’s books, can’t remember which one. Our terrace of 8 houses on Northumberland Avenue was originally called Mulgrave Mall (not to be confused with Mulgrave Terrace or Street, which run parallel).

I can’t vouch for the basement windows’ original format. But I think our other windows are original. In the 15 years since I’ve lived here, most of the windows on the terrace have been replaced, but all the timber-framed ones had that one-over-one format when I moved in (now only 2 of the eight houses retain timber windows). Of course, I could be wrong about all of this. And, as you say, it seems unlikely that the basement windows would have had that costly sheet glass. Do you think they might have been 2 over 2?

Regarding the little horn yokes on the window frames: yes we have those (except where they have were imperfectly reproduced by Ventrolla, 15 years ago… a company I would not be using again, for reasons that I can’t state on a public forum).

Thanks again for your help.

@Graham Hickey wrote:

Indeed – Advance Joinery as Devin says are very often mentioned as amongst the best in the Dublin area, as are Ventrolla who have a great reputation, though may be a bit pricey…

http://www.ventrolla.co.uk/offices/ireland

…otherwise I’m not much help!

Dun Laoghaire is a fecker of a place to date buildings such is the ‘progressive’ nature of window design there as you say. Whilst most places in the city never saw light of a plate/cylinder sheet until the late 1850s, Dun Laoghaire was very advanced for its time. It was largely the seaside location that spurred on the introduction of early sheet glass in the town in what seems to have been the 1840s. Peter Pearson rightly states the introduction of sheet glass as around this time, but often doesn’t mention in his publications that it was pretty much unheard of outside of his much-researched Dun Laoghaire!

I’d still find it very hard to believe though Echium that your house, especially a modest one, from 1838, in the basement, featured sheet glass windows! The fact that your upper windows are single pane sashes and not even early two-over-twos as was the only type available anywhere in Dun Laoghaire in the 1840s, suggests that not only were the basement single panes not original, but that the upper floor ones there today aren’t either! Such hugely expensive windows only came into widespread use in even the most prestigious housing developments c1858-1860.

Are there horns on your windows Echium? – little pointy, often curved features like this:

Golly, Graham. Such sleuthing!

We had only some of the windows replaced by Ventrolla.

I am attaching (I hope) a photo of one of the “original” windows, with the wavy glass. Maybe they are 1860s replacements. Fancy that! What do you think?

And what do you think we should do with the basement windows (which is where all this started)? Do you think we should go for a two over two profile?

@Graham Hickey wrote:

So did you get all your windows replaced in the past by Ventrolla then Echium, or just some of them?
The horns on the windows will tell all – in an instant in fact. If they are long and curved with a dent in the middle as above, then the window frames are at least 1850s, if not later. If they’re only little basic curves, they could well be the original frames but with later replacement glass. Either way it’s likely that you had two-over-twos originally, though I’d still say Georgian sashes are nearly gauranteed to have been there!
Even the rest of the whole street/terrace would not have had sheet glass to start off with – the fashionability of replacing Georgians with sheet in the 1860s cannot be underestimated, especially in Dun Laoghaire!

Thanks, Phil. House not listed, so no grant, as I understand it. I’m waiting to hear back from DLR Co Co on this.

@phil wrote:

Isn’t there various grants available to do this sort of thing? Is it a listed building? There was an exhibition in the County Hall in Dun Laoghaire about windows of the county a few years back aswell, so they might have some info left over from that. Might be worth contacting them.

Well, who would have thunk it! Thanks for your input, Graham. There is no evidence, incidentally, of there having been glazing bars which might have been removed from the frames. So that means that these are entire replacement windows, installed about 1860, going by your info.

If so, then that means that the same folks also replaced the only other windows on the terrace that we had also thought to be original – as these have identical horns and hooks.

Alas, there is no way of contacting the previous owner about the original format of basement windows, unless one is a medium – as he has left this life.

@Graham Hickey wrote:

Thanks for the pic Echium – yes almost without a doubt they are later frames, evidenced as much by the little hoopy hooks as by the fairly decorative horns, the former of which also tended to be later additions (though am not sure what they were used for, maybe suspending the sashes when decorating?).
Your horns are quite restrained all the same, typical of 1850s and early 1860s windows, crossing the line between the basic 1830s/40s style and later post-1860 building boom where they become very rounded and bulky.

To give you an idea of the basic nature of 1820s to 1850s horns, here’s one of the 1844 windows at Connolly Station:

Yes they do feature hoops too, but I imagine them to be later additions, or even the first of their kind, especially considering the Connolly windows are something of an imported style.

So to attempt to sum up your house :), it looks like what were originally Georgian sashes were replaced in the early/mid-1860s with sheet glass windows, going by a) the sheet glass, b) the relatively elaborate horns, and c) the hoops on the underside of the sashes which are so characteristic of post-1850 windows.
However it is just conceivable that the frames you have are still the original Georgian ones – it was very common to cut out the old gridded panes from the main frame and simply insert a clean single sheet of glass rather than going to the expense of fitting entirely new windows. Have a good scan of the sash frames and see if there’s any evidence of filled-in holes! The horns are just about basic enough to maybe scrape it into 1838, though I wouldn’t bank on it!
It’s also possible that the windows may date from much later, maybe even the 1920s when a host of horn styles were in fashion, but I doubt that was the case here: most people jumped at the chance to change out-dated 1830s/40s Georgian grids as soon as it became affordable, especially in scenic areas like Dun Laoghaire.

Are there any other examples of older windows on your street, or modern replacements that give a clue as to what was there before? As for what to do now, a tricky one. It’s very possible Georgian sashes were removed in order to install the aluminiums in the basement – but obviously also possible that Victorian sheets were taken out. If you can find out for certain about the 1838 windows, then personally I’d go with Georgian grid replacements. If you can contact the previous owners, even better!