...from start to finish

We are committed to delivering excellent quality products with a superior lifespan. Our products are superbly engineered and finished to a high standard, reflecting a passion for precision, craftsmanship and technical expertise. Our windows and doors are built to last and to provide you with optimum performance for many years – we provide a 10 year warranty across all of our products. 

We work closely with our supply chain partners to ensure that quality is integral to the design and manufacturing processes of our products. Our chosen supply chain partners have been awarded ISO9001 accreditation. ISO9001 is an internationally recognised quality management system, with a focus on meeting customer expectations, delivering customer satisfaction and driving continuous improvement. Our products also carry the CE mark, which indicates that they conform with relevant EU standards. 

Our preferred installers have been carefully selected to ensure that they work inline with our own quality standards and expectations. Our Operations Team closely monitors the quality of the workmanship on each of our installations through site visits and customer feedback. 

We invite feedback from our clients and ensure that it is shared with all relevant parties, both internally and externally. We work hard to recognise lessons learned, and utilise these experiences to ensure that we continue to provide quality products and a quality service to our clients.

Performance - Thermal and Mechanical

A thermal conductivity image of a Norrsken triple glazed window

Using our high performance windows and doors as part of your new build or refurbishment project can significantly improve the energy efficiency of your home. When selecting new windows you should consider the durability and performance of the whole unit.  Frame materials, glazing features, gas fills and spacer bars all affect the performance of windows and doors. Improving the thermal resistance of a window frame will contribute considerably to the window’s overall energy efficiency (its U-value). The U-value is the rate at which a window or door conducts non-solar heat flow, the lower the value the more energy efficient the unit. 

Frame Material

The low thermal conductivity of wood means that our timber windows are excellent insulators. Although Aluminium cladding does not contribute to thermal performance in its own right, it can allow for the use of deeper glass units, which provide further performance benefits. In addition, because the cladding protects the external timber, the whole window is more durable than the all-timber option. 


Whilst all aluminium frames are strong and light, aluminium is a very poor insulating material. In fact, as a raw material, aluminium is over 1000 times better as a heat conductor than wood (or 1000 times worse as an insulator). Obviously aluminium windows are not typically made of solid metal, but even with multi-chambered extrusions and thermal break layers Aluminium is still a poor relation where thermal performance is concerned. 


The right type of glazing really matters. Key factors here are the glass types used, the spacer bars and the gas filling. 

Glass types

Our double and triple glazed units are produced with one or two panes of low-emissivity (low-E) glass respectively. This heat reflective glass reduces heat loss from the building. It allows the warming infra-red rays into your home but reflects back into the room heat that would otherwise be lost to outside. 

Gas Filling

All of our units are argon filled. This is an inert, non-toxic, clear, odour-less gas used in between each glass layer to minimise heat transfer between the interior and exterior of the window. Argon is 60% better as an insulator than air.

Spacer Bars

The spacer bars (the structural edges between the panes of glass in a unit) are a potential heat loss area. Our warm edge spacer bars are made from a low conductivity plastic and have superior insulation properties. They also keep the glass at the optimum distance apart, accommodate thermal expansion, and prevent moisture and gas leaks.


Both our inward and outward opening units have excellent seals and gaskets, giving low air leakage rates. These five factors – frame material, glass type, gas filling, warm edge spacer bars and the seal used all add up to provide high-performance, thermally-efficient windows and doors.

Your choice... Your style

We understand that the style of your windows and doors needs to be in keeping with the style of your house, and will work with you to ensure that you do not have to compromise on your preferred design.

Our high performance double and triple glazed timber products offer wonderful options for traditional builds all the way through to the most modern homes and Passivhaus projects. Superbly engineered, finished to a high standard and with a range of glazing and glazing bar options, our timber windows will really enhance the look of any property.


We are proud to be able to state that our products conform to PAS 24:2016 enhanced security performance requirements for doors and windows in the UK. This means that they are external doors and windows intended to offer a level of security suitable for dwellings and other buildings exposed to comparable risk. This is now required on all new build projects in the UK in line with the building regulations Part Q.

The very nature of the dense, Northern European pine we use in all of our timber and alu-clad products means that forced ingress is extremely difficult due to the solid and unyielding nature of the timber.

During testing our products are put through loading tests – 200kg of pressure on windows and 500kg of pressure on doors. Once these tests are passed, the products are put through manual attack. If the items withstand the attack for 15 minutes then the product is given the PAS-24 security certificate.

Key-operated, multi-point espagnolettes and multiple locking points to both windows and doors provide extra security and resistance to forced access. 

Laminated glass for external glazing to doors and glazing to side of doors is offered as standard to all Norrsken products that are fitted into a new build project. Security glazing is used where required and glass is glued firmly into place within the sash, unable to be removed even if trims or beads are removed. 

All of these features will substantially discourage attempts to gain access to your property.

Find Your Windows

Let us help you to find the right windows for your project