frequently 
asked
questions

The U value, or heat transfer coefficient, indicates how good the thermal insulation of a window is.

The lower the U-value, the better the insulation. For every decimal reduction of U-value of the window, you get an annual energy savings of 10 kWh/m² window area. Try our energy calculator.

The spacer bar detail is a unique code used to identify products. For windows and glass doors, you’ll find the code on the glazing bar (the gap between the glass), typically on the sides or bottom of the pane. On HomeGuard doors, the information can be found on the door leaf. These codes contain all the necessary information for us to identify the unit and your original order.

No, we don’t manufacture to standard sizes. All our products are bespoke and made to measure, ensuring they are perfectly tailored to suit your project.

We offer a standard range of 16 colours, which you can view on our product pages. However, we can also manufacture products in a vast range of additional colours using the classic RAL, NCS charts and Interpon sable finishes.

If you’re looking for a custom colour outside our standard range, we can accommodate most requests for an additional charge, which will vary depending on the type of finish.

NorDan Hardware department aim to supply hardware orders within 48 hours to site within mainland UK, after the order being placed.

• All NorDan hardware
• HOPPE
• WInk Haus
• Assa Abloy
• Roto

Fogging may occur on the inside (room side) of the glass. Common causes are:

• Excessive indoor humidity and poor ventilation (especially in new buildings)
• Low temperature indoors
• Poorly insulated panel

Interior fogging is not a sign of a defect in the pane.

In cold periods, we (and most other window manufacturers) have received a number of enquiries regarding condensation that froze on the inside. We have therefore asked our glass suppliers to provide us with some information about this.

• Information about interior fogging.
• Information about fogging on the outside of the glass
• Information about condensation and icing on the cylinder sets for doors in winter.
• NorDan's new NTech products and installation suggestions for better, more proper installation of windows in walls

Fogging may occur on the outside of the glass. Common causes are:

• The relative humidity of the location. The higher the humidity, the greater the risk of condensation/fogging.
• The U-value or insulation level of the panel. The better the panel is insulated, the less heat is applied to the outer pane. The surface is then cooler, increasing the risk of fogging on the outside
• The temperature inside the room.
• Blockage, i.e. heat from the panel cannot radiate freely into the sky.

Exterior fogging is not a sign of a defect in the pane.

This may be due to cold drafts

Cold drafts occur when air is cooled by a window. The cooled air is heavier than air in the rest of the room, so it sinks or "races" downward. The air is pushed across the floor by its own weight, giving the impression of a draft. There are three factors that affect drafts: the height, size and surface temperature of the window. The colder and higher the window, the faster the air will sink and the greater the "draft". NOTE! Underfloor heating will not prevent cold drafts by the window.

For better comfort and warmth, use NTech Passive or NTech 1.0 which produces far less cold drafts.

NorDan supplied the UK’s first Passivhaus certified projects and recently have supplied the UK and Europe’s largest Passivhaus projects. The products achieve Passiv standard u-values and air tightness but the products are not certified. We can provide PHPP data to support consultants and we have case studies of previous Passivhaus projects. Contact your nearest technical specification advisor for more details.

Although double glazing is sufficient to insulate a home, but we often get asked if the move to triple glazing is worth it. In other materials, a move to triple glazed can increase cost by upwards of 20% but at NorDan, triple glazed is the ‘norm’ due to our Norwegian roots meaning there is a very low circa 5-7% cost increase to upgrade to triple glazing. With the better thermal efficiency (u-values as low as 0.7 in comparison to 1.2 in double glazed), we see it as a no brainer to select triple glazed! It can provide an increase in up to 40% heat retention which helps reduce fuel poverty.

We offer both EI30 and EI60 fixed windows as well as EI30 FireGuard (external) doors. Our doors have intumescent seals fitted so that in the event of a fire, the intumescent seals expand to 5-10 times their original size sealing the gaps around the door and providing an effective barrier to fire and smoke.

We have many glass options at NorDan such as laminated, toughened, sound reduction, low g-value and lots more. If you have specific targets to achieve, let us know and we can work to find a glass that will achieve these. Regarding privacy glass, we can offer matelux and Cotswold.

All our maximum/minimum sizes and weight limits can be found in our window & door brochure and these change depending on window/door type. If you are still unsure, please do get in touch.

Yes! Please get in touch with your local technical specification advisor and they will be able to provide them.