• Showroom & Head Office

    01923 231 111


  • Premium window range manufactured in the UK by market leaders Origin Global
  • Internal and external flush casement
  • Combines traditional design, advanced manufacturing and versatile premium grade aluminium
  • Uncompromising security features – PAS 24:2016 certified
  • Extremely low maintenance and energy efficient
  • Available in over 150 RAL colours
  • Unmatched 20 year manufacturer’s guarantee

By combining the finest grade aluminium with precision engineering and exceptional craftsmanship, Origin Global has a proven track record in delivering high quality, functional yet sophisticated products that are built to last. See also our ORIGIN DOORS page >>

The OW-70 Slimline Casement Window

The Slimline casement offers ultra-slim sightlines of just 65mm from sash to frame with external flush fitting. High security Nemesis locking system which is PAS 24:2016 certified.

The OW-70 Slimline Window

The OW-80 Premium Casement Window

The Premium casement offers slim sightlines of 91mm from sash to frame with both internal and external flush fitting. High security Yale Encloser Locking system which is PAS 24:2016 certified.

The OW-80 Premium Casement Window

Thermal Efficiency

Able to accommodate both double and triple glazing, Origin windows include a sophisticated polyamide thermal break that’s built into the frame and prevents heat transfer from the inside to outside and vice versa. OW-80 windows can even go the extra mile to achieve a U-Value as low as 0.9 when using Aerogel technology – the same material that’s used in space suits and space shuttles. You can view our Aluminium Installations gallery to see examples of our Origin installations.

The OW-80 French Window

Flawless Colour Spectrum

With over 150 RAL colours available to choose from, you are simply spoilt for choice! In addition, both systems offer a dual colour option, so the exterior frames can match the building style, whilst the internal colour can complement or contrast your interior decor. For an immaculate finish, the highest grade powder coating is applied, creating a durable yet smooth surface that is superbly resistant to the elements.

For further information on all our Origin products, please check out our Origin brochure collection:


      An industry-unique fully flush casement, the Origin Window offers top aesthetics, high levels of security and thermal efficiency.


      Our stunning sliding door range from Origin. Our vision is to transform the way families enjoy their home – from inside to out..


      Unlock your home’s potential with the Origin Aluminium Residential Door, where security and aesthetics are superbly combined.


      Discover more about our premium range of stunning Origin aluminium bifolding doors, French doors and single doors.


      The new collection of ultra modern industrial style steel-look bifolding and French doors.


      A steel-look glazed wall and door system, allowing light, air and space to transform your living area.

See also our ORIGIN DOORS page for our full range of bifolds, sliding and residential doors.

Endorsements & Reviews

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Window unit replacement to a sash

10 Verified Review

Fantastic service from beginning to end. Local showroom in Watford with a super variety of windows and doors The fitment of the sash for my son's bedroom, best decision. Quality window and beautiful finish Paul and Miles are polite and friendly. Paul is a master at his job and Miles is super when finishing and completion. Thanks guys and thank you Harp Windows

Location: WD25September 2023

Replacement front door

10 Verified Review

All appointments on time. Advice useful when choosing design. Fitted in less time than expected.

Location: WD23August 2023

Bay Window Replacement

10 Verified Review

I have to say I have been impressed with HARP from start to finish. I was guaranteed the best price from John at the beginning, There was no hard sell or tricks, Just simple and honest. I ordered 1 window to replace my old bay which I was advised would take 6 weeks from ordering. My window arrived slightly earlier than anticipated and was fitted without delay. The fitting team worked in a clean and tidy manner, were punctual and had a great attention to detail.

Location: WD24July 2023

Supply rear door.

10 Verified Review

Excellent service, most helpful and friendly. Highly recommend.

Location: BH10May 2023

2 x casement windows

10 Verified Review

Very pleased with product and workmanship. All done with no fuss and no mess. Brilliant job. Billy even hoovered up afterwards !

Location: WD18May 2023

New windows and doors

10 Verified Review

Excellent service from both the showroom staff and the fitting team . Quality of the windows and doors is very good , and would highly recommend this company

Location: WD24April 2023

Read all 250 reviews

  • Harp Windows (Watford) Ltd
  • 91-93 St Albans Road
  • Watford
  • Hertfordshire
  • WD17 1UL



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