Glazing
As a general rule you do not have to replace any existing glass that does not meet the standards.
Any new glazing though must comply with the current BCA glazing provisions, such as where an existing building is being extended whether it be one or more storeys.
However, this is complicated by the fact that the glazing provisions are determined on the basis of a whole storey. This mean s that the existing glazing also needs to be “considered” in order to determine compliance.
It may in some cases be unreasonable for new glazing in an extension to compensate for undespec’ed glazing. In this instance, it would be reasonable to determine compliance as if the new glazing were uniformly applied to the whole storey but to require the complying glazing to be installed only in the extension.
We used Energy Rating Consulting to assist us with glazing requirements (and other things) who have been excellent. A typical report will cost you about $400.
The Process
We have agreed with our licenced glazier that we remove all the old glass, clean out any old putty, small steel triangles or nails etc. We also have all the windows pre-painted (undercoat and 2 top coats) all ready to install.
Once installed we will be issued a Form 15 “Compliance certificate for building design or specification” certifying that the windows are “up to code”.
This is where you can save some serious money if you are willing to put in the effort to:
- find a glazier who will work with lots of old windows and doors that have glass in them
- remove any old glass that is not up to Code
- clean out old putty and glass and sand back each entire window/door
- paint the windows/doors (prime plus 2x top coats)
- build new frames
Yes, that’s a lot of effort and time, weeks and weeks. But if you can do it in chunks it can be satisfying while saving $10Ks.
The NCC
The relevant section in the NCC is H1D8 (page 98 of the NCC 2022 or Part 3.6 Glazing of the NCC 2019). Interestingly, the NCC states in Section H1 Part D8 (amongst many other things) that:
(2) Performance Requirement H1P1 is satisfied for glazing in glazed assemblies if it—
(b) is designed and constructed in accordance with AS 1288 for all glazed assemblies not covered by (1) and the following glazed assemblies:
(vii) Second-hand windows, re-used windows and recycled windows.
Decisions
We have decided to replace any glass in any of the “old” windows as opposed to using something like 3M films. The main reason for not using 3M films was that the films cannot be applied to glass that is less than 3mm thick. We have plenty of very old windows with 2mm glass which would have to be replaced anyway.
Putty
There is no such thing as white glazing putty for wooden windows. there really isn’t. Many suppliers sell it as white but it’s not white, at least not white white. Our Links have a few suppliers links, anyway, putty needs to be painted anyway to protected. Check the timing re painting as the putty can’t be too wet nor too dry.
