Issue 41 Spring web - Flipbook - Page 91
spacer bar thickness is 16mm so any decent triple glazed
unit is going to be almost 50% thicker than a double
glazed version. Now with a flush fitting profile being one
of the main requirements of a conservation rooflight, the
introduction of triple glazing makes that almost impossible
on some roof types. It is also important to consider that
triple glazing will add significant weight to the rooflight,
so consideration must be given to the load bearing
structure of the roof and how you will position the
rooflight for installation.
frame profiles or reduced viewable areas. While a white
internal frame can be sold as ‘clean’ or ‘neat’, these can
sometimes feel a little soulless and is a finish more often
associated with modern flat rooflights than traditional
conservation products.
High end conservation rooflight products will be finished
with hard wood, which gives a neat, warm appearance to
the internal element of your conservation rooflight. Some
rooflight manufacturers even offer a choice of your timber
preference, so that you can match other materials in your
home or simply create the exact look you are trying to
achieve.
Should conservation rooflights have glazing bars?
It is often a stipulation from the Conservation Officer that
a conservation rooflight should have a glazing bar to
replicate that original Victorian appearance. It is not always the case but it is definitely worth checking whether
you need them before purchasing any conservation
rooflight.
Single or double glazed?
Victorian rooflights would have been single glazed,
however, today’s modern building standards are much
higher and so single glazing does not meet the minimum
requirements for thermal efficiency (Part L). Double
glazing is now the most popular option for genuine
conservation rooflights because glazing technology is such
that a modern double glazed unit can provide a number
of benefits while remaining reasonably slender. While
offering much improved thermal performance, modern
glazing units can offer a variety of practical choices, such
as self-clean, solar control UV light protection.
If your conservation rooflight does require a glazing bar
then it should be a genuine one. This is an area that
separates those producing close replicas to the original
Victorian rooflights and those who are trying to pass off
modern skylights as something more traditional. A
genuine glazing bar should be something which not only
divides the glazing but also provides additional strength
to the casement. So many conservation rooflights have
something simply stuck or glued onto the outside of the
glass which neither looks good nor provides any benefit
to the rooflight. In addition, these stuck on bars (usually
Some conservation rooflight suppliers are keen to boast
about offering triple glazing in their products, however,
while this does offer a slightly improved thermal performance it comes at the expense of appearance. The optimal
Above, rooflight in bedroom
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