The Tatra Sliding Sash Window

The window and door industry have many ways of comparing performance and some elements of the market do not have a good record of providing easy to understand comparisons and information (think “White Gold”). This is very important because typically the glazing elements of a window or door perform much better than the frame material for energy efficiency, so if you are comparing a very large direct glazed window with a small, heavily casemented window, the performance will seem very different; however, in reality the materials themselves might be identical. To ensure a coherent point of comparison in the performance of products, a standard has been set under British Standards for size and design of items. If you are comparing our products to others in the market, please ensure that these products are also quoting performance figures for an industry standard sized product.

The air permeability of a product is defined through a testing process outlined in BS EN 1026:2000 standard. This test involves placing a product in a formal test rig and pressure testing it to understand the level of air flow through the product at increasing air pressures. This testing delivers an overall performance class of between 1 and 4, where Class 1 is the poorest pass criteria and Class 4 is considered exceptional. There is a range of performance levels within these classes, but the test performance is not defined any further than the four class distinctions. The performance of products in the marketplace can be surprisingly different, so if draught-proofing performance is important to you, then ensure you get a testing certificate from your chosen suppliers to enable you to make an informed decision.

Read more here: Gowercroft windows pass rigorous weather performace tests

Resistance to Wind Load

The wind loading standard of a product is defined through a testing process outlined in BS EN 12211 standard. This test involves placing a product in a formal test rig and pressure testing it to 1200Pa and -1200Pa to understand the deflection of the product and the ability of it to withstand heavy wind loading. This testing delivers an overall performance class of between 1 and 3, where Class 1 is the poorest pass level and Class 3 is considered exceptional. There is a range of performance levels within these classes, but the test performance is not defined any further than the three class distinctions. The performance of products in the marketplace can be surprisingly different, so if resistance to wind loading performance is important to you, then ensure you get a testing certificate from your chosen suppliers to enable you to make an informed decision.

Water Tightness

The water tightness standard of a product is defined through a testing process outlined in BS EN 1027 standard. This test involves placing a product in a formal test rig and spraying water at the product while gradually increasing the pressure in incremental stages. At each stage, the pressure and water jets are continual for at least 5 minutes. This testing delivers an overall performance of Class 1 to Class 9, where Class 1 shows no passage of water through the product at zero pressure and Class 9 still allows no water through at 600Pa of pressure and is considered exceptional. The performance of products in the marketplace can be surprisingly different, so if water tightness performance is important to you, then ensure you get a testing certificate from your chosen suppliers to enable you to make an informed decision.

Read more here: Gowercroft windows pass rigorous weather performace tests

Part Q of the Building Regulations was introduced in 2016 in an effort to improve the security of new housing stock. For a product to achieve Part Q standards, it either needs to have been formally tested by the manufacturer through a stringent security test, or it needs to have been manufactured to prescribed standards and sections. If formal testing is undertaken, it is carried out to UKAS PAS24-2016 criteria at a registered test house. This test involves a series of manual and mechanical attacks which assess the ability of the product to stand up to a potential home invasion. The performance of products in the marketplace varies considerably, so if security is important to you, then ensure you get a testing certificate from your chosen suppliers to enable you to make an informed decision.

Read more here: Gowercroft windows pass strict security tests

Warranties vary in many ways between suppliers. A good warranty should be easy to understand and extensive. Watch out for small print, maintenance requirements, long warranties from new or phoenixed companies, materials-only warranties and anything too good to be true. A warranty should be a relationship and it should be open and honest from the start.

Read more here: Gowercroft AfterCare

An estimated lifespan should give you a good indication of how long a product will last when looked after and maintained correctly. There are many examples of timber products which are still operational after hundreds of years and the actual lifespan will depend on a number of factors including the exposure, maintenance regime, base timber and levels of usage. The figures quoted on this page are taken from a Heriott-Watt study which gives approximate lifespans of windows manufactured from different materials.

This is intended to give a point of comparison between our different product ranges only and not an overall idea of where they stand in the market. Our products are all manufactured to a standard which far exceeds the industry norm and although they are not cheap, they do represent excellent value. If you have other quotations and would like to understand where the differences are, we are always happy to sit down with you and go through the quotations. We believe that when you understand the value proposition for our products you will choose Gowercroft, but we aren’t right for every project and we are happy to walk away if it’s not the right fit.