Buyers will often be persuaded by software vendors who tell them that running their
software is like child’s play. What software vendors should do however, is what
we do, and point out all the problems that can be encountered if proper planning
does not first take place. Only when this is done, can the easiest route to a successful
installation be achieved. Forgive me if I sound cynical when I say that some of
our competitors may have an ulterior motive in hiding potential pitfalls, so that
when the problems are later discovered, they can then charge the customer more to
try to put them right.
One of the most common deceptions experienced by sealed unit manufacturers is the
claim that the details for lead and Georgian units can easily be calculated with
modestly priced software add-ons. In our experience, what can often be omitted from
such bold claims, is the fact that these software add-ons are add-ons to a full blown
window design software package not always included in the quotation. These packages
require that all the possible variations of standard or ad-hoc window designs, profile
dimensions, and various lead and Georgian dimensions be entered, before these software
add-ons can work. The software vendor may offer to enter these figures for say half
a dozen profiles, but there can be many different variations such as heavy profile,
light profile, tilt and turn profile, patio door profile and sliding sash profile
with different spacer insets. Each of these may well be available in hardwood or
softwood timber, PVC, or aluminium. All these variations could result in hundreds
of different profile dimensions for each window manufacturer, a fact not fully realised
by many sealed unit manufacturers.
To prove that we speak with authority about all the possible complications mentioned
above, see the twelve examples of window designs illustrated below. These were output
from our TrimWindow program which was written for a very large window manufacturer
using only their standard profile dimensions in each material and using only standard
dimensions for lead and Georgian inserts. It also copes with swept heads, fire escape
vents and permavents for different materials and also many variations of cills, not
necessarily in the same material as the main window profile. Click on the text links
to see larger versions of each window then click BACK to return here. Only with
drawings of such aesthetic realism, can the impact of any lead or Georgian insert
design, properly be appreciated.
Coping with all these variations in any viable combinations is a quite daunting task
for each window manufacturer. For a sealed unit only company trying to cope with
all these variations for possibly over a hundred window manufacturing customers,
is quite literally a cosmic task. We do not know of any sealed unit company making
less than 5,000 sealed units per week who have successfully achieved this task and
we don’t think we ever will, because the task requires the full time input of a very
intelligent and very experienced window trade administrator. Quite apart from all
the variations mentioned above, there are also various possible options in the way
the lead or Georgian layouts are designed. Lead and Georgian operatives in sealed
unit companies often have very fixed ideas about design practices, but these are
points which should be discussed between the window manufacturer and his customers.
In short, the whole process being discussed here should be the responsibility of
the window manufacturers. If these manufacturers faced their responsibilities, they
would realise that it is often better to make slight adjustments to mullion or transom
positions rather than be forced to face compromises in the aesthetics of the lead
or Georgian layouts. Most window manufacturers who try to place the responsibility
onto their sealed unit manufacturers are usually ignorant of these issues because
their owners have probably never had to work out these details for themselves.
Managers in sealed unit companies often have little appreciation of the sometimes
daunting task faced by their lead and Georgian operatives. They need to know and
fully understand a wealth of detailed figures to be able to do their job properly.
It is therefore no wonder that they often take shortcuts to minimise the difficulty
of their task.
One typical example is the fact that when diamond lead is centralised on the largest
unit in a window, it is then much easier to let the lead in all the other units in
the window line up with this unit, horizontally, vertically and diagonally. Now
click on the Window 9 example below and you will see that the diamond lead lines
up horizontally and vertically, but not diagonally. This is harder to achieve but
the resulting aesthetics are much more pleasing to the eye and this is the way that
our Tudor ancestors did it.
Another example of different approaches can be seen if you click on the Window 5
example. The border Georgian must line up vertically, but it is arguable whether
the top horizontal piece should be inset the same as the vertical pieces in the same
unit, or the same as the horizontal piece in the bottom unit.
These two examples are typical of choices which the window manufacturer should be
discussing with HIS customers.