Our website uses cookies to improve your experience. By browsing this site, we will assume you are ok with this. You can read more on our Privacy Policy page.


Fourwalls is an independent building performance company. Ian set up the company in 2005 having spent the previous 17 years working as a multi-disciplined building services engineer. Initially set up to respond to concerns about the drive for more energy-efficient buildings and the potential impact on the indoor environment, we have evolved to use our knowledge to help the governments of England and Wales develop their Building Regulations for Part F – ventilation, and Part L – energy efficiency standards.

We are based in Bristol and operate across the southwest and south Wales*. We work on individual self-build/retrofit projects all the way through to large and complex non-domestic. Fourwalls has the expertise to help you to operate your buildings most efficiently, and for the well-being and comfort of the occupants. We can help you to:

  • Save energy
  • Target long-term improvements
  • Improve occupant comfort
  • Reduce operating costs

Ian Mawditt – Director

Ian is a building researcher, specialising in the field of building performance in relation to energy efficiency, occupant comfort and indoor air quality. For the last 15 years, he has been part of the AECOM-led technical team that supports the governments of England (DLUHC) and Wales in developing their respective Building Regulations. Ian is the technical lead for Part F (ventilation) and for the building fabric specifications for Part L (conservation of fuel and power), including airtightness. In the latest revisions (Part L 2021), he developed new guidance to help reduce the performance gap and improve compliance levels.

We are pleased to be members of the following associations

*or further afield for larger/research projects