Sustainability policy

Hartwyn flies the flag of sustainability front and centre of everything we do.  It is in the air we breathe.

Our mission is to take everything we have learned as an industry and cherry pick the bits that work the best.  Objectively. Data lead.

We take our lead from the heritage sector where the custodianship of traditional buildings, methods, and materials continually reminds us of what is possible with truly low carbon, low tech solutions. 

Contemporary innovation and building science has increased our understanding of these materials and provided an expanded palette from which to draw.

True sustainability folds in our history, our heritage, and our present, and builds towards a future that is inclusive, ecologically balanced, fair, and enriching for all.

Permaculture provides the simplest way to visualise the shape this takes:

We care for the Earth by building low impact, low carbon, high efficiency buildings.


We care for people by creating inclusive, fair, and open work environments. By building healthy structures that will benefit generations to come whilst looking after the wellbeing of those around us and the planet we live upon.


We share fairly by adopting a consistent ethical standpoint in all elements of our business and interactions. Integrity is at the core of all of our actions. 


Once we move passed our core sustainable values it gets pretty technical, pretty quickly. We are signatories to:

  • Construction Declares – working from within the construction industry to mitigate climate change
  • The Architects Climate Action Network’s campaign to legislate carbon

We are founder members of SBUK and NBUK, members of the AECB, ASBP, The Green Register, The Low Impact Living Initiative and The Passivhaus trust.

We are accredited Passivhaus contractors, experts in natural material specification and installation, and educators to self builders and the industry. 


For more technical information on how we build sustainably, please see our circular economy policy.