Sliding Sash Window Design (Double Hung) History

By Andy the stuff doer

The Sliding Sash Window, or Double Hung Window as its called in America, is showing a massive upsurge in popularity. 

It’s an fantastically successful design. A 100 or 200 year  lifespan is proven.  Compared to around 20 years for uPVC windows, the timber sliding sash window is a winner. 

In these days of energy conservation the traditional Double Hung Sliding Sash is unsuitable as a replacement window.  Unfortunately the tradition design is unsuitable for fitting the double glazing units that regulations stipulate. 

Many companies now manufacture alternative designs, some good, some in my opinion, very bad.  It’s obviously a highly profitable market, with strong demand and high margins. 

A couple of years ago, I embarked on project to build my own double glazed sliding sash windows.  No suitable plans where available so (as a trained designer) I set about  researching the subject in great detail. 

This post relates to the my Synopsis of  sliding sash window history.  Read the article over on my website.  

Various window designs including Double Hung, Sliding Sash

An understanding of historical window designs to inform 21st century developments

I’ve analysed the construction details of the Box Sliding Sash. (Available soon.) This has allowed me to fully understand the tried and tested construction. It highlights where, in the light of modern developments, the design can be evolved.  I’ll be publishing construction details and plans for an evolved, traditional sash window shortly. 

The final part of project will be available as a set of plans, details and explanations for a 21st century fully evolved sliding sash windows.  Combining technology with craftsmanship, these windows can be built in a shed with a minimal investment in tooling. 

Any comments or thoughts or INTEREST ? Please give me you feedback below. 

Historial Influences on the Design of Sliding Sash Windows 

Prototype  Window Build Blog

80 Responses to “Sliding Sash Window Design (Double Hung) History”

  1. please let us know when your plans are ready we will be very interested as we have a lovely old house but need to replace a lot of 1700 windowns, thaks

  2. Will Do.

  3. Hello Andy,
    Please put me on your list for the sash plans. C’mon now, don’t let two years go by!

  4. Hi Andy
    Like you were, we’re too broke to pay (recent quote) 1k per window. I’m handy with wood, so I would love to see how far I get with your plans.

  5. Thanks A May-Zubel, The plans are on a slight hold at the moment whilst I’m checking if any design protection is worth sorting out first. I’ll post as soon as there is some progress.

  6. Niall Rhys Evans on April 9th, 2012 at 2:30 pm

    Hello Andy
    Saw you great vid in the PT 85. It has its downfalls but for the price and space saving looks like a good buy. Just one thing most of the reviews on this say the fence is poor and some people have made their own fences or made mods to it. As I am about to buy one i am sure that the fence will let me down but if a good mod is out there then i can make the changes myself. Any ideas. Thanks

  7. Hi Niall, Good to hear you found the review useful. The fence mod I use is about as simple as it gets. It s a length of squared up 2 x 4″ hardwood, that a clamp to the out feed table. For the odd occassion I need this facility it works fine. If I’m jointing boards I tend to use the table saw as I find it easier to get a staight and square edge.

  8. J. sent this comment in by email:

    I’ve now found your web page and I read your blog on making a sash window with interest. You certainly did a very thorough job which looks very good and it was very interesting to see how double glazed units can be squeezed in.

    I have just made a sash box frame too, but used the old sashes that were already there. The frame was in terrible shape which is why I rebuilt it. The back of the house has subsided so the frame had twisted and was very rotten, but it did give me template to copy construction details and dimensions. One thing that strikes me is how basic the box frame on my house is compared to the one that you’ve made. It really is bits of planed timber nailed together. Only the pulley stiles which have a groove for the parting beads, and sills had any machining as such. However I still ended up with a very sturdy frame.

    Also I don’t know if this is interesting to you but on my house the detail of the original box frames around the arch are slightly different to your window, and help to make the windows look a bit more “period”. Down the sides of the window there is a scotia bead nailed to the front linings to cover the gap between the window and the brickwork. There is also a horizontal scotia bead mitred to the two vertical ones and nailed to the top lining on the window head so that the top edge of the bead spans the brick arch. A wooden arch filler is then nailed to the top lining through to blocks behind so that is is flush with the scotia bead and therefore infront of the main window box. This then fits into rather than behind the brick arch at the front. It could be that the detailing of windows in your area is different, but round the midlands that is a pretty standard way of doing things. I’ve included a photo of a rather ropey but salvageable window from my house. (the one I’ve made doesn’t have the sashes in yet)

    Also If you haven’t already seen them (I guess you probably have) there is some very good info in period joinery books which in fact describe construction very similar to your very high quality construction. Haslucks “carpentry and joinery” and also “modern practical joinery” by George Ellis which is available new are very interesting.

    Also I have used a simple but I think effective way to deal with the pocket pieces which might be interesting to you. I just cut top and bottom of the pocket pieces on a 45 degree angle all the way through to the parting groove. Then took a rectangle of 3 – 4 mm hardwood maybe around 2″ by 1″ and cut a recess in the back of the pulley stile to glue and screw the hardwood piece into so that is overhangs the top of the pocket piece hole by about an inch. A corresponding 1″ recess in the back of the pocket piece means that the pocket piece sits in its cut out and is held in place by the hardwood plate at the top and is screwed with 1 screw at the bottom. To me it is a bit neater than trying to cut angles in the pocket piece. Of course the method I described is not so suited if the pocket piece is in the centre rather than the back of the pulley stile. What do you think?

    I am of to read some more of your page now.

  9. Good to hear from you J.
    I’ll have to look up the thread to remind myself when I get a moment, was it something about the gaps and tolerences?

    The frame design I eventually used is a combination of old designs with a few new/modified details that I decided would have some benefits. Particularly the stile to cill joint that is often the the first parts that shows signs of rot. Other details help to fix the dimensions that I needed to ensure a consitent gap for the seals to work in. So yes there is some added complexity. It great to see a good frame, like yours, can be built with just PSE.

    The scotia bead is like you say a way of covering gaps. It also adds a bit fancy detail, some I’ve seen really go to town with the beading and mouldings, I can imagine the the “window salesmen” of the day upselling all the add ons they could. I’ve seen the infill board used around hear as well it allows a standard fram to be used in an arched opening. I just choose to make make the outer lining tall enough to fit behind the arch so the extra piece wasn’t required.

    The pocket cutting is an interesting one, I’ve seen and heard about them being done many different ways, as far as I’m concerned as long as works it doesn’t matter how they are made. One thing I did come across in my research was a special pocket cutting chisel. I fashioned my own version and gave it a go. Pocket Cutting Chisel. With this chisel I can see why the “old time” design ended up as it did. (see the illustration on the page, not how it is on the video).

    It’s certainly all interesting stuff, trying to work out how and why things where made as they were.

  10. Hi,

    I recently came across your site, and have to say you are providing some great information, not commonly available otherwise. I have been looking for info on how to build sash windows for about a year now so I am hopeful that you will have plans available? Either way keep up the excellent work, it really is appreciated.

    Mike from York (now living in france)

  11. Hi Mike, Thanks for your comments . The Window Plan are “work in Progress” unfortunately the day job plus the whitby cottage renovation is knocking it back. I’ll let you know when Ive made progress.


  12. Hi Andy, Watched your 4 panel door with great appreciation , terrific!
    I too, like Mike from York, think It would be great see you do a sash window? If it turns out to be as good as the door it too will be terrific .

    pls keep me in the loop
    Alan (Australia originally Oldham)

  13. Thanks Alan, The windows write up and photos are in pipeline. It’s a long pipeline though with all the time I’m spending on the cottage. I could do without the day job for a few months. I’ll let you know when I’ve made any progress. In the meantime if you do “Facebook” we have a page where I post the links to anything that I have managed to cover.
    All the best

  14. well done excellent

  15. I’m really impressed with your videos. I made a box sash at college once and would love to see if i could create something of quality for home. I look forward to seeing your designs and having a go. Keep the motors running!
    Cheers, Patrick

  16. Thanks Patrick, As soon as my day job eases up a bit I’ll be on to it.

  17. I’m interested to see how your project turned out. Were you successful? I see some very old comments on this but I don’t see where you updated the blog to show your results. I’m interested to see how the windows turned out.

  18. They have turned out very well and having gone through a few winters now I can say with confidence they are performing and holding up well. I’m hoping my day job quietens down a bit so I’ve chance to update things and get working on the plans.

    Thanks for looking and commenting

  19. Hi Andy, I’m in a similar position in needing to make windows as purchase is just not an option at current prices!
    I hope you get the time to do the plans at some stage, you made such a lovely job if the picture is anything to go by. So please make a note of my email and let me know as soon as they are available.
    Best wishes, Dave

  20. Will do Dave. I’m planning on semiretirement from my day job soon, the plans are high up on the list of things to do in the extra time.

  21. Hello Andy, just found your site and found this blog most interesting. I didn’t realise there was so much interest in the sliding sash.
    I worked in a C & J Department in a FE College and had to make up some box sliding sash windows for the students to have a go at re hanging weights and minor repairs etc. I still have a setting out rod for the side boxes if you are interested, it’s on MDF but i can re set out on lining paper and forward to you if you are interested or of any use. It could be easily scaled either way and might be useful to anyone who is interested.

  22. Hi Garry,
    Apologies for the late response. Setting out rods are something I’ve thought about covering at some point. If you could send me a photo of yours I might be able to use them. Rods tend to be specific the stock sections either bought or “home made” and for others to print out to scale would be difficult so it’s probable best to show how folks can make their own. You can email me at

  23. Hi Andy,
    Many thanks for all your time and effort with this – assume it’s a labour of love.

    Completely agree with your response to L. Quatermas. While i can understand his point of view and his need/desire to protect his skillset and tradition (and i truely hope he does so), i find the whole traditional window industry protectionist (read over-inflated prices, often with little to justify it – actually, the best craftsmen can justify it, the rest just copy the prices and think the wealthy will be happy paying for it). The closest industry i can think of is Swiss Watches – everyone knows they are hugely inflated just to protect the industry. That said, i hope both industries remain and keep doing it the proper way.

    But for me, i’ve paid for two different window manufacturers and both were rubbish (glued on pieces here and their, staples, softwood (3 piece) cills etc) so i’m taking matters into my own hands and building my own – i have a window here to model from (not copy, because as far as i’m concerned, i’m not going to make their mistakes/shortcuts and will improve on some of their designs). As an ex-engineer I’ve CAD’ed up my design (happy to share it) based on readily available U/S Redwood sizes from my local timber yard. If it works out well, will consider re-doing it all in sapele or iroko. As for Douglas Fir, i’ve never seen or heard of any windows or even quotes in that (though may not be looking in that end of the market), let alone cedar (other than my parents’ house near the sea in Sydney which is all W/R cedar due to the harsh environment).

    On a side note, my understanding is that any window manufacturer must supply the overall U-values for their windows for building regs, but can you honestly tell me with all these ‘old-school’ trandional crafsmen that learnt it from their fathers, they are taking their windows to the testing labs to get accurate figures??? i’d be suprised, and have yet to get any formal certificate from the two manufacturers that have made windows for me so far.

    Back to the point, i found your site because i’m exploring designs for pockets…appreciate your method, but prefer my fancy tools over my hand-skills so will be doing something more akin to ‘J via email’ and artificially make the reverse angle cut with a backing piece.

    Great work, we need more people like you to share their time and experiences.


  24. Hi Andy, I find your Whitby Cottage restoration very interesting and inspiring. It’s good to see that practical skills and necessity combined lead to some brilliant solutions, clearly you’ve researched and thought through each challenge in depth.

    I am currently refurbishing our Victorian terraced home and trying to restore some of the features lost to modernisation and in the future wish to replace the current pvc windows with original sash windows as part of the long term plan.

    Long story made short, any progress on the windows plans?


  25. Hi,
    Firstly, compliments and many thanks for sharing.
    I am extremely interseted in your sash window design. This year I am making some windows for my property which I hope will be a confidence builder for a couple of sash windows I am going to attempt later.
    One question I have (possibly my most concerning one) is possibly more a decorating one but is something I would like to cover during manufacture. I live in the South West (UK) and am coastal. All windows suffer terribly from the environment and bleaching from the sun. I have considered soaking my timbers in a piece of guttering filled with some kind of preservative for a couple of days, is this silly?

  26. H Mike, The plans are still in a very long pipeline, life and work keep getting in the way. Preservative will only help with fungal and possibly insect damage. As it has taken me so long at least I’m gaining first hand knowledge of how linseed oil based paints performs over years. So far I’m really impressed, no cracking, blistering or flaking. Cosmetically the surface does degrade over a few years but the protection is holding up. Timber expands and contracts following ambient humidity levels and paint does the same with temperature changes. The linseed handles it, I am a convert.

  27. Thanks Ian, Really sorry I had not got back to sooner, I’ve got a massive spam problem that I’ve only just had a chance to plow through (one advantage of the snow, I’m in the office instead of on-site or in the workshop). Glad you found the cottage stuff interesting, having finished that I’ve had a full refurb to do in a victorian terrace and half way through another semi. I’ve got so much material to write up, I could do with break which I might get in about 6 months.

    Long story short, no progress on the window plans but at least I’ll be able report long term performance of the design. I post any progress.


  28. I read this article completely concerning the resemblance of newest and earlier technologies, it’s amazing article.

  29. Great website. Would love to know how you get on with your self build sash windows and would happily pay for any plans you produce.

    Thanks Donald.

  30. I have just refurbished curved Bay with 3 sashes, and the only way to get them out is externally, First take outer flat timber ,this is where the outer sash goes down the side of.Then take parting bead out ,it will probably snap.then the sash will pop out ,with a bit of multi tooling and easing.

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