Whatever your project, we’re here to help make your vision a reality
At NK, we know every project is as unique as the person behind it, so we work directly with you to create the best solutions for you. From the initial design consultation through to manufacturing and installation, our friendly and expert team will be with you every step of the way.
Better by design: find out why our windows have the edge
NK’s high-performance windows are all built to exacting European standards for durability and to make homes warmer and more comfortable: choose from fixed, sliding, outward opening, or combinations that include our versatile Tilt & Turn design.
Create an outstanding welcome with our high-performance doors
From front doors, to bifolds, sliders and French doors, all our doors are expertly built, offer high levels of security and superior insulating properties that will reduce your home’s energy consumption to keep you cosy and safe all year round.
Your dream door awaits
Work with one of our design advisors to create an impressive entrance. Whatever your style, we can create the door for you.
The smart choice – find out why nobody regrets choosing uPVC
uPVC windows and doors provide superior insulation and security, boast greater durability, and require less maintenance, making them an energy-efficient and cost-effective choice for discerning homeowners worldwide.
0800 344 3126 | info@nkwindows.co.nz
17 Hammersmith Drive, Wigram, Christchurch 8042
04 384 9909 | info@nkwindows.co.nz
03 445 0172 | info@nkwindows.co.nz
Unit 1, 4A Ree Crescent, Cromwell 9310
Find your local NK
Talk directly with one of our team and get a closer look at the quality and structure of our windows and doors.
Our team is ready to answer your questions, provide a quote, share insights, and help you choose the right products for your project.
News from NK
Frequently asked questions
Technical terms explained
See our Glossary for any terms you want to clarify
Where are NK Windows products made?
The uPVC profile undergoes precision cutting and welding, with steel insertion and the fitting, testing, and glazing of opening and locking hardware all taking place in our Christchurch factory. Our glass is custom processed and cut by Viridian Glass.
What is uPVC?
PVC is short for polyvinyl chloride, a type of plastic widely used in construction and various industries since the 1950s. uPVC, or unplasticised PVC, is a specific form of PVC that is highly suitable as a material for window frames.
Its versatility allows it to be used in diverse applications, ranging from window frames and pipes to medical products.
Are uPVC windows tried and proven?
Absolutely. The roots of uPVC windows trace back to 1959 when the first commercially available windows graced homes in Germany. Over the years, technology has advanced, and yet, some of those initial uPVC windows are still standing strong. In fact, more than 60% of European homes now boast the reliability of uPVC windows and doors.
Are uPVC windows environmentally friendly or recyclable?
Yes. Viewed across its lifecycle, uPVC is highly competitive in terms of environmental impact. Several recent eco-efficiency and Life Cycle Assessment (LCA) studies on the most common applications show that, in terms of energy requirements and GWP (Global Warming Potential), uPVC is at least equal to alternative products. In many cases, it shows advantages both in terms of total energy consumption and lower CO2 emissions.
The core materials for uPVC production – chlorine and ethylene – are both by-products of other manufacturing processes. Chlorine is a by-product of caustic soda production with source raw materials of seawater and rock salt. Ethylene is a by-product of the petroleum refining industry i.e. PVC is not directly dependent on crude oil.
Our frames are also highly recyclable.
Can uPVC windows handle the harsh New Zealand sun?
Absolutely. Our PVC profiles specifically engineered with New Zealand’s climate in mind, including those intense UV rays. The same robust formula stands resilient in other high UV environments such around the world, such as the Middle East, Australia and Latin America.
Are uPVC windows and doors suitable for renovations?
Definitely. Many of our customer projects involve renovations. We understand the importance of preserving character, and our robust uPVC frames are perfect for bungalows and villas.
Do you have outward opening windows?
Yes! We offer a full range of outward-opening windows, with traditional or contemporary styling. Find out more here
Do uPVC windows require special glass?
No. “uPVC windows” refers only to the frame material. We have access to the same glass options as any window supplier through our partnership with Viridian Glass based in Christchurch. Most common options include:
Why choose uPVC over aluminium or wood?
Aluminium – there are several reasons to choose uPVC instead:
- Thermal performance – aluminium is highly heat conductive so they are not well suited to temperate climates and houses fitted with them require additional energy consumption for heating and cooling and often suffer condensation problems. See here for more detailed information.
- Health – condensation breeds mould and with mould come dangerous spores. Such environments have been proven to be associated with respiratory illnesses: nose and throat symptoms, cough, wheeze, and asthma symptoms. There is also evidence that these environments can be associated with shortness of breath, the development of asthma in people who did not previously suffer from it, and lower respiratory symptoms (coughing, wheezing, chest tightness, and shortness of breath).
- Environmentally responsible – aluminium is produced from the non-renewable ore, bauxite. Aluminium production requires a great deal of energy (225MJ/kg) and it generates huge amounts of environmentally dangerous pollutants like carbon dioxide, acidic sulphur dioxide, along with polyaromatic hydrocarbons (PAHs) fluorine and dust. Although New Zealand does produce aluminium, all raw materials are imported: bauxite/alumina from Australia, crude oil from Alaska USA, and coal from China and Korea – again adding to the environmental impact of aluminium windows. See here for more information.
Wood – there are equally strong arguments for choosing uPVC over wood:
- Environmentally responsible – most people believe using wood is the most environmentally sensible option for window frames because of the “natural is better than synthetic” assumption. But if wooden frames are to maintain their technical and thermal properties, they require regular treatment with chemicals that are often very environmentally unfriendly.
- Lifecycle – DEFRA (Department for Environment Food & Rural Affairs – UK government) commissioned a study into the lifecycles of PVC and timber in window profiles. In analysing the various impacts across the lifecycle, it was found that there are only marginal differences in the environmental performance between the two. Although trees are not a scarce resource, the facts around de-forestation, particularly logging of ancient or old-growth forests, warrant further understanding. The logging of these forests can lead to a decrease in biodiversity, as habitats are destroyed in the logging process. Tree plantations are grown, in their place, for the intense farming of timber and wood products. This itself can lead to soil erosion and nutrient degradation, vulnerability to pest attack, reduction in water supply, over use of fertilisers and social impacts.
- Sustainability – Caution needs to be taken in accepting claims of an increase in forested areas. Scandinavia presents an interesting example relating to the misconceptions surrounding so-called ‘sustainable forestry’. Eco watchdog, Friends of the Earth comment: “More trees are not a good thing when they are replacing valuable wildlife habitats. Scandinavia has now just 5% of its original old-growth forest remaining, yet this is still being logged. Also almost 50% of Finland’s peat bogs have been drained, mostly for planting managed forests.”
- Quality – like most items of organic origin, not all wooden windows are the same. There are good quality and poor quality wooden windows available in NZ. Poor quality wooden windows can warp and delaminate. uPVC gives you a quality finish, every time.
How do I take care of my uPVC?
Regular cleaning and maintenance are essential for all windows, as they can accumulate stains and damage over time due to pollution, weather, and various other factors. By adhering to proper cleaning and maintenance guidelines, you can optimize the appearance, functionality, and longevity of your windows.
See our After-care section to assist you in caring for your windows.
Do I need planning permission or a builder?
Navigating the regulations for planning permission can be intricate and perplexing. Permitted Development offers the opportunity to undertake specific home development projects without planning permission. However, it is crucial to adhere to planning guidelines to prevent any costly errors. Contact our team to find out more.
Under normal circumstances you will not need a builder if replacing windows and doors, we will do the work required. However, we do not carry out structural work, so in that case, the services of a builder would be required.