British Standards Testing
All Costello Windows products are tested to British standards. This helps us achieve low U-Value windows that are A-Rated. All our windows and doors are rigorously and independently tested for weathering by Build Check. Official signed certification available on request.
Costello Windows fitting crews are the best of the best. Our fitters have a wealth of experience and have been with us for many years. They always finish jobs to the highest standards and will only leave once the customer is 100% satisfied. With experience comes knowledge and with very few jobs being the same it is so important to have a fitting crew that knows what they are doing. The first part of any project is to make a high-quality product, next they must be fitted correctly. Sometimes unforeseen problems will arise when fitting, this is where experienced fitters come into their own. Fitters with experience can problem-solve on the go and take such situations in their stride. Costello Windows fitters are always courteous and patient and listen to what our customer’s requirements are.
To ensure that our customer gets the highest quality we have employed, trained quality control personnel, who will not allow a product out of our factory unless it is of superb quality. Every product is checked along the production line to ensure that it is perfect. Finally, when the product is complete it is put aside for a final quality control inspection. If any defects are found they are corrected. When the product has been passed, it is stamped and only then can it leave the factory.