Plastic sash windows

[plasticpigeon]

I would really like to design a very cheap plastic sash window as an alternative to the cheapest stomproof casements. I'm not saying I'm going to do anything about it, but I want to at least make some initial investigations.

I realise if sash windows are to make a comeback they need to be super cheap. I have been thinking how this could be achieved. These are my thoughts. Spiral balances are horrid as they have lots of friction and seem to break easily. I have never used a block and tackle spring balance but I imagine these might be better, however they will never have consistant force throughout the sash travel. Weights and pulleys give a really nice feel, and if weights can be made in steel need not be expensive. Only one sash needs to open, which would leave space for a large weight which could be made in steel to balance a double glazed window. Alternatively a pulley system could be used to allow a more normal sized weight to balance a double glazed sash which would allow for 2 moving sashes, but I think this is straying from the super cheap brief. I dislike welded mitres. I imagine a screwed joint could be designed that would allow the joint to mimick a mortice and tenon with rail and stile. This would mean it could be made without welding equipment. Glazing bars would need to be stuck on.

Some early sash windows are mounted flush or very close to the face of the brickwork of the building they are in. Often it doesn't look like there is a big enough box to house balance weights. Were these windows not balanced and held open with something (book, shoe, servants head or some specially made chock perhaps). If so these would need spiral balances as the frames are too thin to accomodate a weight.

Does anyone know if there are any cheap plastic sash windows on the market at present and if so what the price for an average sash (say 150mm x 100mm) would be. Also as I am loathe to get a double glazing firm round my house, does anyone know how much really cheap casements would cast for a similar size please?

I know that nobody here is in the market for cheap plastic sashes, but if anyone has any other thoughts, please let me know.

 

[MatthewC]

Glazing bars would need to be stuck on.

Presumably your ideas would include double glazing, so the glazing bar could be inside or outside. There are arguments against both...

what the price for an average sash (say 150mm x 100mm) would be

I'm just guessing but I think you mean cm not mm!

 

[plasticpigeon]

yep cm

 

[TheRoost]

I found a site a while back that compared prices of standard UPVC casement windows, UPVC sashes and timber sashes. I can't find it now but I think it said that UPVC sashes tend to cost around 30% more than UPVC casements. Plastic casements seem staggeringly cheap when I hear what others have paid to have the whole house done plus French doors, around £3k for a semi is fairly typical - this is a fully fitted price too!

I'm not sure the current cost of UPVC sashes is a barrier.

google 'Colinssashwindows' they sell UPVC sashes at any size up to 130cm x 240cm high, for £249+VAT :shock: and if you want it bigger than that, you'll have to stump up an extra 30 quid :shock: colours available at extra cost too.

There is a thread on here somewhere about my sightings of plastic sashes in my area - it's a fairly average suburb but every Victorian house that has sold recently has immediately had white plastic sashes fitted at the front - even £140k terraces. We are the odd ones out for not rushing to replace our casement windows with more plastic - but we'll stick with what we've got until we can afford timber sashes.

If you can come up with a design that looks more genuine than what is currently on offer, and is competitive pricewise, then go for it.

 

[plasticpigeon]

Thanks theRoost. I also found Colin's windows yesterday searching the web. £300/window is really cheap, I don't think it is easy to do better than that.

You obviously live in a nice area, where I live all windows are immediately replaced with the cheapest casements available, hence wanting to find/make an alternative. I do wander sometimes whether people actually like the ugly windows because the ugliness and clunky design makes it obvious that they are new. People do love new things. I'll try and find your thread, but any chance you could post a link to it please?

 

[TheRoost]

Found it -
http://www.periodproperty.co.uk/forum/viewtopic.php?f=1&t=15197

It's only nice in parts, there's plenty of 1930's houses that have had cheap bulky casements fitted too, I suppose Victorian ones tend to catch my eye more often, and probably only 10 of them have been sold in recent years.

You might be onto something there, they want their brand new windows to be instantly noticeable to the neighbours, and not just look like they've had a clean/repaint!

Just a thought, I sometimes see upvc sashes on ebay for very little money, even £30 (where they have been made to the wrong size/ordered incorrectly etc.) perhaps you could acquire one of these, then strip it down to see how its made then look at where it could be improved?

 

[Flyfisher]

These so-called 'plastic windows actually use aluminium extrusions for their structural elements don't they? Just thinking out loud, but would it be possible to replace the plastic covering with wood to give a better looking final result? I realise 'better looking' is subjective but I suspect I'm on safe ground saying it in these here parts of the interweb.

 

[plasticpigeon]

I think they are steel inside. I can't see the point of wrapping steel in wood though, may as well use wood. PVC is good for those who think they are maintenance free, which they are, until they break.

The idea of buying a plastic sash and deconstructing it is a great one, I think I'll do that.

 

[Me!]

What about having no balance weights at all, but having the two sashes linked via a rope over a pulley at the top so that as one goes down it makes the other go up to balance it?
Obviously this would mean that when the window is open, both sashes would actually be in the middle and there would be equal openings at the top and bottom.
Not original I know, but this way would require less bits to make it, and you said you wanted cheap!

 

[kreyszig]

I'm with FF in a way - I think the worst part of PVC windows is the appearance of the PVC. If that could be improved you'd be on your way. Painted/powder coated aluminium can look pretty good and is virtually maintenance free. Not sure on the price side of things though.

 

[plasticpigeon]

Aluminium is a terrible insulator.