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To be known as the trusted go-to brand when creating healthy, comfortable and energy efficient homes.


To close the industry knowledge gap through a design-led supply chain of products and services to help architects, specifiers and contractors achieve the necessary building performance.


At 21°, we believe you thrive in the places where you experience comfort.Delivering a low energy or Passivhaus building is complex, and you need a solution rather than a single product. At 21°, we are committed to using a whole house approach to provide better performing buildings from a comfort, cost, and carbon perspective. We supply a range of specialist products and services, including triple glazed timber windows and doors, MVHR heat recovery ventilation, insulation, and airtightness products. We’ve worked hard to build a reputation for customer service, integrity, and responsibility. We are committed to ensuring that our products are of the highest quality, backed by industry accreditations, and specified by companies at the forefront of energy-efficient construction. By choosing us you can rely on expert consultation at every step of your project. 


Founded in 1995 by three experienced building professionals and formerly Green Building Store, 21° continues to be involved in energy-efficient building projects throughout Yorkshire and the north-west.

From those small beginnings, 21° has expanded to offer a wide range of products and services, including triple glazed timber and alu-clad windows and doors, advanced MVHR heat recovery ventilation, specialist airtightness and insulation products, as well as in house consultancy. 

21°has been a passionate proponent of Passivhaus design and continues to offer a comprehensive range of Passivhaus products and services for the UK. Their ground-breaking work has facilitated the construction of Passivhaus buildings in the UK and the promotion of ‘best practice’ in low carbon construction. Its former in-house building team built the pioneering Denby Dale Passivhaus and Golcar Passivhaus Stirley Farm EnerPHit projects. 

21° head office is situated in Huddersfield. 



Timber Frame Triple Glazing Windows and Doors

Airtightness Products

Passivhaus Building Services

Advisory and Consultancy Services


Offering nationwide service from showrooms in

Huddersfield and the NSBRC in Swindon.


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