Frequently asked questions

What is the U-value for Strømmen’s windows and doors?

We offer doors and windows in timber, alu clad timber and aluminum. The U-values depend on the glass, configuration and size of the product. Detailed technical specifications can be found on the product pages.

How do I take measures?

Accurate measures are a must before ordering a door or window. We recommend taking measures of the wall opening and not old doors or windows. 

  1. Take measures from the outside.
  2. Take three width measures and three height measures from brick to brick.
  3. Deduct 20 mm from the narrowest width and shortest height.
  4. You are now left with the width x height of the new door or window.

How do I install doors and windows?

It is important to install the products correctly. You can find our installation guides here.

What is the delivery time for an order?

We normally ship products 4-6 weeks after receiving an order. We are flexible with delivery times and will always find a good solution together with our customers. The delivery times can vary depending on the production schedule and size of order.

What causes condensation on glass surfaces?

External condensation is caused by the high energy efficiency of new glass units that prevent heat loss. It is a sign of quality and not a defect in the glass unit. External condensation usually occurs when the seasons change from winter to spring and autumn to winter. The condensation disappears in the morning when the sun starts heating the air.

Internal condensation is caused by excess moisture in the room. Humidity indoors can lead to damp walls, patches of mildew, mould and deterioration of plaster. We recommend ventilating as often as possible

Can Strømmen’s doors and windows be manufactured to individual customer requests?

Yes, all our products are made-to-order. Our engineers will consult you and try to find the best solution for your project. There are some restrictions for maximum height and width, but this is different for each product. Please check the specifications of each product or contact us for more information.


Which surface finishes do you offer?

You can choose any RAL colour and six standard anodisation colours for our aluminium products. Timber and timber/alu products can be painted in any RAL colour and NCS colour, and several types of water-based lacquer. All our products can also be supplied with different colours on the inside and outside.



Where do you deliver?

All our products can be delivered all over Europe. Our experienced team will arrange the transport and take care of all shipping documents. The products are packed safely and placed on pallets to prevent damage during transport.