GHW Windows are members of CERTASS, CERTASS is a Competent Person Scheme gives installers the chance to self-certify their work and ensure it complies with all the local Building Regulations. This means they can work on your home without the need for an inspection from local authorities, saving both time and money.

These schemes help tradespeople prove their ability to do work, and consequently drive up the standards of the building industry as a whole.


As a member of the Glass and Glazing Federation (GGF), as a business we have been recognised for our commitment to providing high quality installations within the glass and glazing sector.

GGF are the major authority, promoting best practice and sets the highest technical and health and safety standards across the industry. The GGF is a government recognised authority and is influential in the new standards and regulations such as the  Building Regulations 2022. This ensures homeowners across the UK are protected and up to date with the latest home renovation techniques.


The Glazing Arbitration Scheme (TGAS) is an independent ADR (alternative dispute resolution) scheme and the primary ADR for the Glass & glazing industry. As a member of TGAS in the unlikely event that you the consumer are unsatisfied with the service provided, TGAS will step in as a fair and impartial arbitrator to evaluate the case without the need for lawyers or face to face meetings. This allows for a cost and time effective solution for all parties involved.


Great Harwood Windows is a business with a Quality Assured National Warranties (QANW) backing. A fully regulated insurance provider, ensuring that insurance products are delivered every time to provide homeowners across the UK with peace of mind when considering their home renovation projects including, double glazing, conservatories, windows, doors and roofline products.

Trustmark registered

Being registered members of Trustmark, we have demonstrated our continuous commitment to delivering the highest standards of customer service, trading practise and technical ability.
Being the only Government Endorsed Quality Scheme in the UK, you can rest assured you’re in competent hands with a Trustmark registered business. Any business given Trustmark approval has been thoroughly vetted and monitored to ensure they maintain the necessary standards in technical competence, trading practise and customer service so that homeowners can make informed decisions without bias.

external view of a house with a garage and black composite front door

Find out more about our fully accredited glazing products

Accreditations help to give homeowners peace of mind that they are working with a professional and reputable company. Click on the links below to find out more about our range of fully accredited glazing products.

Composite door vs aluminium doors

Spitfire aluminium doors

Conservatory roof replacements

Full house installation with flush sash windows

“Very happy with the installation and service provided by Great Harwood Windows. The work was completed on time by very friendly and professional staff. Any issues we had were quickly resolved and replied promptly when we called or emailed.”

Mr Diwan - Blackburn

May 31, 2024

“Fab! Brilliant job, great lads, looks amazing – thanks. Also appreciate how clean and tidy you’ve left everything!”

Mrs Dawson - Burnley

May 1, 2024

“Just wanted to say a big thank you to the team for all their hard work in ensuring that the product and installation was perfect. We are really happy with the windows and it was a pleasure working with you all. “

Mrs Taylor - Manchester

April 25, 2024

“I just wanted to feedback from today’s installation. From start to finish, we only have compliments. Every contact has been profressional and straight forward, all company employees I’ve met when they measured up, and when installed, have all been an asset to your company. The standard of the fitting of the windows is perfect, and the courtesy of each person has been exemplary. I don’t usually send reviews or emails like this, but I feel that I should on this occasion due to such an amazing positive experience. I’d highly recommend your company to others. Thank you very much.”

Mrs Lunn - Ambleside

April 9, 2024

“the lads came this morning and fitted my new composite door and replaced all my front window glasses a really nice and professional job done two really nice lads thank you very much”

Mr Matthews

March 19, 2024

“Absolutely brilliant service from start to end. GHW are very professional and the products they supply are excellent quality. Can’t recommend this company enough.”

Mrs Morley

March 1, 2024

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Based in the heart of Lancashire

Situated in the very heart of Blackburn, we are readily capable of providing the people of East Lancashire and surrounding areas with a range of UPVC, composite and aluminium products. Whether for personal or trade purposes, realising your aspirations are only one step away with Great Harwood Windows team.