The Glass and Glazing Federation (GGF) has acknowledged a significant rise in the number of manufacturers producing narrow cavity insulating glass units with an edge-seal sightline of 5-6mm, designed to meet the need of improved energy performance for windows, particularly in the heritage sector.
The increased demand for narrow cavity insulating glass units derives from guidance by local planning and conservation authorities who have called for units to be glazed into timber windows with through-glazing bars with lower than normal rebate depth.
The GGF states that all insulating glass units placed on the UK market must have passed EN 1279 Parts 2 and 3, whilst achieving EN 1279-4 component manufacturer confirmation.
At Sunsquare, we have always taken seriously our position as market leaders for the design and manufacture of energy efficient, contemporary flat roof skylights. Our glazed units feature an argon-filled cavity, along with thermal breaks between the inner and outer panes using polyamide insulating sections, to greatly reduce overall U-values.
A U-value is a measurement relating to the transfer of heat (in watts) through one square metre of glass, divided by the difference in temperature across the structure. The lower the U-value the more thermally efficient a living or working space i.e. a reduced chance of colder and warmer external temperatures affecting your interiors.
U-values are covered by Part L Building Regulations, which set out maximum U-values for new-build developments. The current legal limits under Part L are as follows:
- Roofs – 0.20 W/m2 K
- Walls – 0.30 W/m2 K
- Floor – 0.25 W/m2 K
- Party Wall: 0.20 W/m2 K
Note: Roof windows, curtain walls and pedestrian doors have a limit of 2.00 W/m2K.
As a consequence, we work closely with architects to provide architectural rooflights that enhance the energy efficiency of an overall project. Make sure you take a look at our portfolio of recent domestic and commercial projects to experience the impact of Sunsquare rooflights on various builds across the country.