img(height="1" width="1" style="display:none" src="https://www.facebook.com/tr?id=2939831959404383&ev=PageView&noscript=1")

The importance of thermal performance in rooflights

Know your Ug values from your Uw values and specify products custom designed with the glazing and frame working in harmony

In association with
Designing with daylight: Vario by Velux Rectangular and Long Slim rooflights in a kitchen extension.
Designing with daylight: Vario by Velux Rectangular and Long Slim rooflights in a kitchen extension.

With Vario by Velux, architects can have confidence in the thermal performance of the rooflights they specify.

The company provides both the bespoke glazing and a fully insulated frame (upstand) for optimal insulation, energy efficiency, reduced environmental impact and comfort for building occupants.

In order to design sustainably it is important to understand the distinction between Ug and Uw values when evaluating rooflight energy efficiency.

The Uw value represents the overall thermal transmittance of the entire rooflight, encompassing the glazing and the frame. The Ug value focuses solely on the thermal transmittance of the glass itself, excluding the frame.

A useful way to remember this is: Ug  = Glass only, Uw = Whole Window.

For architects seeking eco-friendly solutions, it is important to pay attention to both Ug and Uw values.

  • Vario by Velux Long Slim rooflight.
    Vario by Velux Long Slim rooflight.
  • Vario by Velux Rectangular rooflight.
    Vario by Velux Rectangular rooflight.
12

Why Ug and Uw values matter

Energy efficiency Rooflights that have low Ug and Uw values help prevent heat loss through the glass and frame, reducing the need for heating and cooling. This saves energy, reduces greenhouse gas emissions and strengthens sustainability.

Passive solar design Well designed rooflights with optimal Ug and Uw values harness natural daylight and solar heat gain, maximising renewable resources. 

Reduced environmental impact High-performance rooflights enhance a building's energy efficiency, resulting in a smaller environmental footprint. By consuming less energy, we preserve natural resources and minimise the harmful effects of energy production, such as air pollution and carbon emissions.

  • Ug = 0.5[W/(m2K)].
    Ug = 0.5[W/(m2K)].
  • Uw =1.1[W/(m2K)].
    Uw =1.1[W/(m2K)].
12

Specify glazing and upstand from one source

Some skylight suppliers provide the Ug value only, as they might only supply and produce the glazing alone without the upstand.

To make well informed decisions and choose rooflights that offer the best energy efficiency, thermal comfort, and align with sustainability goals, it's essential to ask for both the Ug and Uw values.

These values provide a comprehensive evaluation of the rooflight's thermal performance, considering the product as a whole.

Choosing Vario by Velux means opting for a company dedicated to a sustainable future.

Specify rooflights that are custom designed with both the glazing and frame working in harmony to ensure excellent thermal performance and energy efficiency.

For more information and technical support around specifying bespoke rooflights for your clients, visit vario.velux.com


Contact:
01592 778246
vario@velux.co.uk


 

Latest

Towers should be the built embodiment of Gulf cities' ambitions and values, both on the skyline and at street level, writes Kourosh Salehi, whose practice is designing the DIFC Living high-rise scheme in Dubai

Towers should be the built embodiment of Gulf cities' ambitions and values, says Dubai architect Kourosh Salehi

The RIBA president elect and founding partner of Weston Williamson reports from a recent visit to a boutique hotel he designed in Spain, which provides a variety of courses and cultural activities

The RIBA president elect reports from a recent visit to a boutique hotel he designed in Andalucia

A recent court case involving WhatsApp messages provides a wake-up call for architects to review their communications with clients

A recent court case involving WhatsApp messages provides a wake-up call for architects to review their communications with clients

Extend an historic subterranean venue, create a garden zone in a city square, lead two projects on a former Harland & Wolf industrial site - some of the latest architecture contracts and competitions from across the industry

Latest: Victorian subway extension

How will global environmental, economic, population and technological shifts affect future practice? Two experts in forecasting look at the likely impacts

How will global environmental, economic, population and technological shifts affect future practice?