Issue 46 April 25 web - Flipbook - Page 60
Planning Officers Are Looking Closer
It’s worth noting that planning scrutiny of rooflight
specifications has evolved in recent years. Conservation
officers (quite rightly) no longer accept the simple
addition of a glazing bar as a ticket to approval. There is
greater awareness of construction methods, profiles, and
proportions.
Modern equivalents must meet today’s performance
standards for insulation, condensation control, and
weathering, but they should do so without sacrificing
material authenticity. High-grade stainless steel, for
instance, offers a corrosion-resistant, slim-profile alternative to traditional ferrous metals, maintaining visual
continuity while improving longevity.
A flush fit is now considered a minimum requirement.
Beyond that, officers may ask:
• Does the product replicate the fine, slim steel profiles
of a traditional Victorian rooflight?
Likewise, internal linings play a more significant role than
often appreciated. In many heritage projects timber is the
predominant internal material, whether exposed rafters or
timber-clad ceilings. A genuine conservation rooflight
should offer a hardwood liner that visually complements its
environment. Too often, architects discover too late that
the internal finish of a rooflight is plastic or bare aluminium
- jarring with the character of an exposed timber ceiling or
heritage plasterwork. By then, it’s too late to change.
• Is the glazing bar structural or merely cosmetic?
• Is the internal finish appropriate to the surrounding
building materials?
• Can the rooflight accommodate modern performance
standards without compromising on historical accuracy?
The Importance of Section and Profile
Historic rooflights were typically made with minimal
framing, set flush or nearly flush with the roofing material,
often with delicate, hand-fabricated profiles. Modern
products that seek to replicate these rooflights must pay
equal attention to proportion and section, especially as
viewed from the exterior.
Architects must be prepared to answer these questions
with confidence. That means understanding more than
just product codes, it means knowing how rooflights are
made, how they sit in the roof, and what makes them
genuinely compatible with heritage buildings.
Material Matters
A key differentiator between true conservation rooflights
and their lookalike counterparts lies in materiality.
Traditional rooflights were made from cast iron or steel,
set directly into the roof structure, often without an
internal lining.
Deep or bulky sections can appear alien on a slate or tile
roof. Capping details, edges, and visible hinges must all be
considered in terms of visual weight. True conservation
rooflights prioritise slenderness and shadow lines, creating
a light touch that respects the building’s roofscape.
Below, Stella country estate
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