Roof and façade windows
Preserve our shared building and cultural heritage with cast iron windows
Many listed or preservation-worthy buildings in Denmark have roof and façade windows or other cast iron windows. At GH Form, we produce and restore historic cast iron windows for our common building and cultural heritage.
With respect for original craftsmanship and aesthetics, we recreate beautiful, period windows that harmonise with the building's original architecture. At the same time, we make sure that the windows are insulated and meet modern-day energy-saving requirements. The roof windows are approved by the Danish Agency for Culture and Palaces for use in listed and preservation-worthy buildings.
Roof and façade windows
We stock roof windows in sizes and formats that match the most common types of tiles and roof coverings. If you need roof windows in other sizes and formats, we are happy to customise them for your project. All roof windows are presented as original in accordance with the cultural heritage regulations for listed and preservation-worthy buildings.
Cast iron windows for facades
Our cast iron facade windows are solid and durable. The windows are often cast for listed buildings and buildings worthy of preservation, with the aim of preserving the historical expression of the building. We customise cast iron facade windows in all sizes and shapes, including arched and round windows. We also offer renovation of existing cast iron façade windows. The renovation can take place onsite or at GH Form in Borup near Køge.
Standard roof windows
If you need roof windows in other sizes or formats, we are happy to offer customised solutions to match the requirements of your project.
Get the right advice
A window is not just a window - and especially when it comes to preserving the historic look of a building, it's important that you choose the right roof window. Our experts will help you find the right type of roof window to match your building's tiles and roof cladding for a look that harmonises with the architecture and history of your building.
Renovation of cast iron windows
At GH Form, we offer professional restoration of facade windows and other cast iron windows, where we carefully rebuild damaged areas and provide a durable surface treatment. The result is cast iron windows that not only retain their historic appearance, but also last for many years.
New production in original design
If the original roof windows or cast iron windows have not survived the test of time, we can recreate them with precision and high quality. Our experts recreate the original shape to create new cast iron windows that are true to the original design while meeting today's requirements for both functionality and energy efficiency.
Our dedication to craftsmanship and quality is unwavering. We uphold our craftsmanship traditions and the good workmanship that is part of our DNA.
Cast iron roof windows approved by the Danish Agency for Culture and Palaces
Before ordering new roof windows, it's important to consider the options we offer. Read the technical specifications we have for our cast iron roof windows.
Standard
The roof window is supplied as standard in SG iron, coated in RAL 7021 Light Pearl, with 3 mm float glass inserted, putty and painted with linseed oil paint. The window has a sliding bar and anchors.
Standard cast iron roof window with fully moulded frame and sash:
> Cast iron frame
> Cast iron frame
> Glass
> Glazier kit, painted with linseed oil
> Gas springs (on 9- and 12-pillar windows)
> Anchors and extension bar (both coloured in RAL7021)
The coupled roof window is also fitted with:
> Insulated inner frame
> Thermo window in removable aluminium frame
> Window automation (optional)
- If a motor is installed, the window can function as a smoke vent
Glass and glazing
Roof windows come standard with 3 mm float glass.
If you want different glass, we have the following types:
> Toughened glass
> Restover glass (machine made)
> Mouth-blown glass
> Tempered glass
> Fire glass
Thermal glass
The coupled frame roof window comes with a 4 + 12 + 4 mm thermo-low energy pane and insulated frame. The degree of insulation is between 1.6 -1.8W/m2K.
Engine
We offer motors. The control box can control 4 windows. We recommend 230 V. Remote control, wind and rain sensor sold separately.
Gas springs
Gas springs are recommended for 9-pane and 12-pane windows. They facilitate opening and closing of the large heavy frames and are not visually dominant.
Surface treatment
The roof windows are supplied as standard in the colour RAL 7021 Light Pearl in a weather-resistant paint C4 high. Available in other colours upon request.
Renovation
Some old cast iron roof windows do not require replacement but simply restoration. GH Form has the experience and expertise to offer this restoration work.
Uninsulated or insulated roof windows?
It may be a good idea to choose a coupled roof window despite having an unheated roof space if you eventually want to convert the roof space into living space. An uninsulated window cannot be retrofitted to become a coupled window later.
Other types of cast iron windows
It is possible to order other types of cast iron roof windows, such as oval or round roof windows or larger studio windows. If there is a demand for roof windows made to special dimensions, the cost of modelling must be expected.
See our projects with cast iron roof and façade windows
At GH Form, we have many years of experience in renovating and manufacturing roof windows and other cast iron windows.
Frequently asked questions
What does coupled frame mean?
The original roof window consists of an openable cast iron frame with a single pane of glass in the glazing bars, making the window appear original. Thermo glass is fitted inside the same cast iron frame.
The coupled roof window is cast like the original roof window and has an aluminium frame with insulation attached to prevent condensation.
Renovating old cast iron windows?
Some old cast iron windows do not require replacement, but simply renovation. We have a wealth of experience and expertise to offer restoration work on old cast iron windows.
What glass can I get in the roof windows?
Roof windows come standard with 3 mm float glass.
If you need different glass, we offer the following types:
Drawn glass, Restover glass (machine made), Mouth-blown glass, Tempered glass, Fire glass
Which tiles do your roof windows match?
As a starting point, we have standard windows for Old Danish wing tiles or JP hand-laid wing tiles from Monier, JP1, JP2, Randers tegl, Frederiksholm and natural slate - flat roof and thatch. The complete overview can be found in our catalogue "Historic Castings".
For other types of brick that are close in shape, these standard windows can be used, but allow time for customisation during installation.
What do I do when you don't have the roof window I'm looking for?
Non-stock windows can be project manufactured based on existing roof cladding.
Are your windows insulated?
Yes, all our roof windows can be delivered insulated or uninsulated. An uninsulated window cannot be retrofitted to become a coupled window later.
Why should I choose cast iron roof windows, do they not form condensation?
The cast iron material matches older houses from before 1950. They help to emphasise the well-proportioned overall impression of the architecture of a pre-1950 building. If you choose the coupled cast iron roof window, you also get an energy-optimised modern roof window that is tight and condensation-free. The roof window has been tested by the Danish Technological Institute and approved by the Danish Agency for Culture. There have never been any condensation problems: this is due to the interaction between the highly insulated frame and the aluminium frame.
Can you get a motor for the roof windows?
Yes, we offer motors for the roof windows. The control box can control 4 windows. We recommend 230 V. Remote control, wind and rain sensor sold separately.
What colour are the roof windows?
The roof windows come standard in the colour "light pearl". It has the RAL code 7021 and a graphite black colour with a pearl structure. A structure that breaks the surface and creates depth in the colour. Other standard colours are gloss black to match black glazed roof tiles. Brick red with RAL code 8004 - These colours are all supplied as standard and free of charge. The inner frame of the roof window is supplied in "light pearl" as standard, but can be ordered in white for an additional cost.
Other colours can be requested by stating which RAL colour you want. Additional costs and delivery time may apply for special colours.
Do the windows come with gas springs?
Yes, we have gas springs on 9-pillar and 12-pillar windows. The black gas springs are approved by the Danish Agency for Culture. They facilitate the opening and closing of the large heavy frames and do not appear visually dominant. However, they can easily be unhooked if the owner finds them detrimental to the appearance of the roof window.
How long is the delivery time for the windows?
As a general rule, delivery time will be 6-8 weeks for our standard windows. However, some window types may be in stock at the time of enquiry. This means shorter delivery times. Contact us on +45 59 44 09 90 for the delivery time for the desired window type.