Who We Are

Combining contracting services with knowledge and resources to provide the best assistance available in Natural Materials and Sustainability in building.

Everything revolves around creating a new normal.

A normal where we create high-performance structures using natural materials and deliver them efficiently and practically, blending heritage techniques with new technologies. The best of both worlds.

Helping Industry professionals to understand and use materials and techniques which are more accessible and less harmful to the planet.

Creating skilled natural builders who have a knowledge, understanding and preference for materials and techniques which are more accessible and less harmful to the planet.

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What We Do


Providing specific contractor services for new build or retrofit. Filling the principal contractor role for you or your clients, we gain a deep understanding of your design, unify the vision, and translate it practically and sustainably.

Consult and Specify

Taking the risk out of using these materials and save you the time it takes to master them. Defining the supply chain and providing critical overall materials support and Whole Life Carbon analysis for your project. 

CPDs and Education

Providing online courses for professionals. Subjects include; natural materials, passivhaus basics and building science. Digital resources include clinics and virtual Q&A sessions plus a supportive online community

The Process

Ready to help you at all stages of the process. Think of it as a menu. Choose the things that apply. Download PDF here

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Why Consider Natural Materials for your Projects?

Let Hartwyn take the risk out of specifying unconventional or specialist materials for yourselves, the client, or the principal contractor by providing specific knowledge and backup for installation and maximum sustainability.

Natural insulations not only keep the building warm in winter but cool in summer. They help balance the temperature; storing heat and releasing it later, creating a consistent and gentle temperature gradient.


Natural materials and heritage techniques make the most of gentle curves and soft shapes, as well as the natural grains of wood. They are however, versatile and lend themselves well to contemporary architecture, integrating seamlessly with bold new designs and traditional or alternative buildings should that be required.


Natural finishes are vapour permeable, allowing a building to move moisture from interior to exterior so the building will not suffer from damp, mold, and rot. People are a huge source of moisture; showers, boiling kettles and breathing all release millions of tiny droplets of water. Natural plasters like clay and lime actively take moisture out of the building.

Health Benefits

Natural materials do not contain VOCs and other chemicals which off-gas during their lifetime. We spend a lot of time in our homes and buildings and it makes sense to us not to pollute the air our clients breathe. Clay plasters (for example) actively filter the air, preventing mould spores which are also bad for your health.

Sound Deadening

Natural materials are excellent acoustic insulators, helping to create quiet, calm spaces that can be easily isolated from each other. Whether it’s a room within or an adjoining property. 

How can we help you use them?

Natural materials remain on the fringes of the mainstream. That’s not because of performance, so what are the barriers to adoption and how to we overcome them?

A lack of certification and familiarity leads to concerns over correct use, and therefore liabilities. We provide technical guidance, specifications, and case studies to mitigate that risk. Government legislation is also fast paced and usually short sighted and impenetrable. We help you to keep up to date with the recent policy and the guidance it is based on.

Passivhaus and Performance

Passivhaus is a well-understood but under-utilised standard and integrating natural materials into it and other standards is much easier than people think. Hartwyn can help select the materials to achieve seriously low carbon, high performance designs.

Skill Shortages

Hartwyn are providing CPDs and education resources to the industry. But we also understand that time is our most precious resource. When ongoing commitments to these on top of a normal workload are too much, we know, so you don’t have to.

Procurement and Specification

What is the best option? Is it available? Where from? Who will supply and install it? Simply not knowing what is out there is a huge problem. The range of new technologies and materials changes constantly. We are constantly building a library of detailed specifications, in-use examples, and case studies.

What do you want to do?