Double glazing wooden windows

bearshare

In the past, I have seen quite a number of posts about options for insulating wooden windows in older houses. Many would rather not have PVCu for various reasons. I had this problem a few years back, and am very happy with the solution I used. Note this is NOT advertising, just one option that can be considered if you want to keep the original look of the house.

Mine is a 1920s double fronted house with 4 x bow windows. Each bow window has 6 x large windows, and 6 x stained glass leadlights. 3 of each are openers (3 x opening top-hung leadlights, 3 x opening casements). The problem with old widows are: draughts around the opening windows, condensation on single glazing, heat loss and difficulty opening.
PVCu was considered, but this has a number of drawbacks. Less obvious ones include: 
- frames are thicker, to hold multi point locking systems, and reduce the glass area and proportions of the windows. (This may be ok on some windows, but not for these bow windows)
-- they  cannot, at reasonable cost, replace the stained glass leadlights. Coloured films are nothing like the same. (This was a major issue for us. The stained glass is a big part of the character of the house
- the usual, 'storm-proof' windows look  very different externally. Alternative, flush windows are twice the price.

The solution we used was to have all the large windows replaced with new wood, and thin double glazed units, keeping the existing frames, sills, ledges etc. These were made offsite, and primed ready for painting. 
The leadlights were retained, but refurbed with new hinges, and made to fit better.
The openers of both types of window were routed to accept draught proofing strip. All hinges replaced with stainless steel versions.
The insulation/condensation issues of the small, leadlights were solved by using magnetically attached Perspex sheet. This is attached to the inside of the frame immediately surrounding the glass, does not affect opening and is almost invisible.

I am very happy with the end result. The windows (unless you look VERY closely) appear to be unchanged. But, draughts and condensation have gone. Rooms are much warmer. Openers can be opened easily.  They still need occasional  painting, but the inside can match your colour scheme, and the outside can use modern, flexible paints that are much easier to apply and last longer than old types.
Cost turned out to be little more than PVCu replacements.

Just an option.

TELLIT01

All fair comment, and you are clearly happy the result.  The thin double glazed units won't be as effective as thinner ones, but you have retained the look you wanted for the property.  A cousin of mine had the sash windows in her 18th century cottage refurbished and double glazing installed in those.  She also was very happy with the result.

bearshare

TELLIT01 said:

All fair comment, and you are clearly happy the result.  The thin double glazed units won't be as effective as thinner ones....

I assume you meant 'thicker.
There may be some difference, but as the thin double glazing uses krypton, with half the conductivity of the more usual argon,, the difference in practise is not noticeable (by me anyway). The manufacturers actually claim they are more effective than thick, argon filled, units.