Friday, 30 October 2009

Box Sliding Sash Window Plans and Construction details

The first of my box sliding sash windows has now been installed for 10 months. It's still looking good and functioning well. The seals are keeping it draught proofed, there are no signs of any joint movement or wear and the double glazed units are performing as they should.

The only slight problem has been a sash cord stretching so one of the weight touches the bottom of box. I just need to move the knot up a bit.

Details and Construction of DG Timber Box Sliding Sash Window plans to Download?

It's now on my list to build the rest. Before I do, I will review the construction details and amend the plans if I can think of any better ways to do things. I'll write up and draw all the construction details, including measurements and installation. I'll also detail the manufacturing using basic workshop tools.

I plan to make all the details available as an ebook, available for a small charge. If you are interested please leave a comment to give me the motivation to crack on.

The sums seem to add up if you have the knowledge, skills and time. A bespoke bought window would cost around £1000 each and a home made window around £300. I've justified equipping my workshop/garage with part of the savings I'll be making. If I could have bought the plans a year ago I would have.

Let me know what you think.


Enda said...


Love the blog! Can I ask a quick question - what type of timber have you been using? How do you ensure it won't warp after purchase? I'm hoping to make some new internal doors, and would appreciate any advice on timber choice/selection etc.



Andy said...

Hi Enda,

Glad you love the Blog. It's good to know it's appreciated.

Your question is a good one so I'm going to write up an answer in depth but in the mean time-

To answer your questions I can refer you to previous postings


seasoning timber


To flaten a board that had a twist in it - flatening-new-piece

On the subject of doors, you might want a quick look at cupboard door on my loft conversion blog I wish I'd covered in more detail.

I'll post a link here to the new article when it's up on blog

Good luck with doors

Enda said...


thanks for the reply - kep up the good work


arn said...

This is what I want to do. Great stuff.Would love to buy yr plans etc. Any chance you doing an e-book ?

Andy said...

Thanks Arn,

It's on my To Do List. The more encouragement I get the higher up the list it gets. So thanks to you're comment I'll get on to it sooner.


Ben said...

I have to say I think your blog is fantastic. What a great person you are for sharing all the pics and information! I would pay for the plans if you made them available. I've been searching the web for hours trying to find plans and all I can find is a million companies wanting to sell me windows. I'm trying to specify a "venetian" sash (which is one big sash in the middle, with another smaller sash either side - ie three sashes in a row). I can't figure out how wide the sash boxes should be as they will need to take two sets of weights rather than just one. Any ideas how wide (i'm Awesome blog.

Andy said...

Hi Ben,
Glad you like it, it's comment like your that make it seem worthwhile doing.
During my research I have come across old designs for what you are looking at.
Although I've not got the details, this could be something to consider. The Midle sash weights are at each end with pulleys routing the cord over the side sashes. This will give you wide (double) weight boxes at each side but keeping the box between the sections slim.
The width of the boxes depends on the section of the weights you're using + clearance + linings. e.g 50 + 15 + 18 (+ another 18 for your middle box).

Cheers Andy

Ben said...

Hi Andy

Thanks for the reply. Subsequently I've spoken with a sash window maker who suggested the same - ie all the weights are in the outer boxes. This effectively means the inner boxes can be whatever thickness (give or take). The hard part now is to decide the proportions between the three windows - I wish there was something like a golden ratio for them (there probably is but I can't find it). You could put a great book together on the history of english sash windows (there's an interesting but dry book on the history of english brickwork)...

Thanks for your time and continue the blog!

Andy said...

Cheers Ben,
Don't think I'm up to writing a book just yet. Could be good idea for content on my new website.
Thanks for the idea.

Andy said...

I've put together a beginners guide to buying and preparing timber. It covers your questions: What type of timber have you been using? How do you ensure it won't warp after purchase?


Enda said...


got that - many thanks!


Willie said...

I've enjoyed reading the posts Andy - would purchase ebook, let me know when its ready!

Be great to have good plans/sketchup model of pieces would good as well.

Andy said...

Hi Willie,

It's at the top of list now. In fact I was going to buy the timber to make the rest and perfect the design today. BUT I've been snowed in.
I'll be giving the timber some time to fully season before I start and use that time to learn Sketchup.

In the mean time I'll keep posting progress.


Sash Window said...

Think the blog is great. Glad to hear the windows are performing as they should.

philip said...

hi, great blog thanks, very impressive work, would be very interested in an e-book and willing to pay. Please can you tell me how you addressed building regs requirements for replacement windows (searched but couldnt see a reference to it in your blog, apologies if i missed it)
thanks again

Andy said...

Hi Philip,

Thanks for your feedback, It helps spur me on.
All the wood is sitting in garage, resting before being planed up. So I'm getting closer to proving the improved design and publishing the plans.
Building regs. Yes, they do need to comply and they will. Although I've not got piece of paper to prove it yet. One area I'm working on at moment is "ventilation". I would get away with it our naturally drafty house but I'm designing a "slick" hidden vent system to meet the 5000mm2 requirement. These should ensure the design will meet regs for all installations.
All the best

alimorg said...

Hi There love the blog, just what I was looking for some great tips there, I also found these whilst scouring the web for sash window stuff:

Hope they can be of use to someone

FourEd said...

Love the blog. Thanks for sharing. It is very important that you do use the correct timber to make you windows otherwise you will encounter problems within a few months of fitting.

Its nice to see someone wants to take the time and effort to make and fit their own windows, although experience is needed to ensure you don't have draughts/leaks through the joints.

julian said...

Any progress with the plans? I'm also joining the queue of people wanting to pay for your e-book.

Happy writing and drawing!


Anonymous said...

I too am awaiting the plans - very drafty georgian house with rotten 1980's windows means i wont lose interest!


Luay said...

Thanks for all your efforts and I too would pay for some plans. If you, or anyone else is interested I have found some traditional plans (no mention of double glazing or vents!) in an old book by Hayward -

Andy said...

Thanks Luay, I'm making some headway now, I'll keep up a progress report.
Cheers Andy

FourEd said...

Great post.

You certainly do notice it when you have new windows installed. The house feels more secure and less drafty.

Thanks for sharing.

commentor said...

Andy, thanks for the blog - fascinating stuff. I have existing sash windows, and your blog makes me think that replacing the sashes with DIY-made ones (while keeping the existing boxes) might just be doable. The frames would probably be narrower than one might design if one were to completely replace the entire window. I expect draught proofing might be more tricky with in-situ frames.

Kate said...

I love sash windows and am so grateful for your blog! I love learning all abuot them. I want some for my barn conversion, although my carpentry skills arent up to much so I am going to a supplier of sash windows Cornwall, but it will be good to know how they work and to be able to ask intelligent questions along the way.

Andy said...

Hi Kate, If you "love Sash Windows" then the supplier you have linked to will be very dissapointing. I can't see timber sliding sashes on their website, just ugly plastic versions.
Hope your comment wasn't just for the link?

Chris said...

I noticed on the picture you have installed draught seals into the sashes. Have you installed draught seals to the sides of the sashes or onto parting and staff beads?

Andy said...

Hi Chris,
Thanks for your comments. The brush strips are on the sides of sashes. It's different from how most modern sashes are now done but I didn't want the brushes or seals visable.

JD said...

I have just completed my second sliding sash window, having copied ones I have seen. I could not find plans/drawings anywhere, so would be interested in any you may have.
First one was daunting and I made it all a bit tight (I live on a windy hill), and had to readjust all the beads, but second one was more relaxed and came out much better.
Great blog. I know how you feel!
All the best, Jonathan.

Andy said...

Hi Jonathan, Sorry the plans are not available yet. The delay is now down to some of the details being unique and needing design protection. The process is on-going and I hope to be able to anounce some news soon. Great to here you've done well with your first two. Keep up the good work.
Cheers Andy

Andy said...

Hi Jonathan, Sorry the plans are not available yet. The delay is now down to some of the details being unique and needing design protection. The process is on-going and I hope to be able to anounce some news soon. Great to here you've done well with your first two. Keep up the good work.
Cheers Andy

Box Sash Windows said...

Hi Andy,

your blog have really good information and very helpful to choose the best box sash windows amongst the all available.

Certie said...

Hi Andy.
I am a time served Carpenter and Joiner, with over 40 years experience I think box sash windows are great, I have made quite a few over the years.
I will be teaching the construction of these windows over the weekends starting at the end of Jan 2013,
I am looking for learners who love these windows as much as I do. Keep up the good work, lets start a war against upvc replacement.

Anonymous said...

Hi, do you have the plans available yet? I'm hoping to start my window renovation soon.


BTW... Love the door artical

Henry Sears said...


I see this is a few years old, but I wonder if you ever produced your ebook of plans? I'm just buying a house needing a few new sash windows and would love a copy if it's available!

And thanks for the inspiration...

Andy Bell said...

Hi Henry,
It's still on my very long to do list. Sorry to have got hopes up. On the plus side when I do get round to doing the plans I'll have the confidence of knowing the how the windows have performed over a number of years.

All the best with your new house

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rich44 said...

Hi Andy, very interesting blog. Would be interested in plans etc.

Also interesting to see how prices have changed. I have 4x triple sashes and 4x bays to do. Quotes coming in at £50k.

1 triple sash is about £4500 fitted, I think materials is about £500-£600.

I'm thinking of getting a decent combination machine to make my own on.

Interesting method to use bead plates or facing beads, never seen that done before.

Also I see that you have very little notching on the cill for the pulley stiles to sit in. These are usually deep and tapered allowing use of a wedge. I guess modern glue and screws will cope?