The Team

Based in the UK and with over 30 years of experience the practice has an extensive track record of completed ecological buildings for a range of individuals, NGO’s, councils, schools and charities:  Clients have included: Garway Village Hall Trust, Helena Housing Association, Marches Housing Association, Melin Housing Association, Disability Essex, National Centre for Alternative Technology, National Trust, County Naturalists’ Trusts, Six Bells Trust, Shropshire County Council, Caerphilly County Council, E.Sussex CC, Weald & Downland Open Air Museum, Keyhole Trust, Green Wood Trust, Severn Gorge Countryside Trust, also various Primary and Secondary schools.

Core Staff:

Architectural design and technology: Andy Simmonds, Adele Mills . Other staff as projects require.

Specialist consultants:

Energy and Services: Gervase Mangwana of Waxwing Energy, David Olivier (Energy Advisory Associates) and / or Alan Clarke.

When a PHPP (passivhaus planning package) model of the design is required, we work with either Waxwing or Tim Martel.


We prefer to work with engineers we’ve built up experience with ; either Build Collective, Bristol or BJSE, Shrewsbury.

Adele Mills

Adele has been a registered architect since 1989. Before setting up the partnership with Andy Simmonds in 1992, she worked as an architect for Leeds Federated Housing Association, and for private practices in Bristol and Liverpool. This was a great springboard of experience in architectural practice; contract management, low-cost housing, community projects, public participation, before deciding to set up Simmonds.Mills with Andy Simmonds.

In the early years of Simmonds.Mills, Adele worked on site developing her building and site management skills, particularly in the more specialist ecological techniques – earthen construction, pole and other carpentry techniques. Using these skills, she carried out many hands-on building training courses for women and young people. She has been a design tutor at Cardiff University School of Architecture, and at the Centre for Alternative Technology. This hands-on practical experience has been invaluable for design skills.

Current specialisms in the practice are in the fields of design aesthetics; client and community participation; planning negotiations; contract administration.

She has recently completed the AECB’s Carbonlite Retrofit course and is a qualified Retrofit Designer.

Andrew Simmonds

is an architectural designer & partner in Simmonds.Mills Architects as well as part-time Chief Executive of AECB – the Association for Environment Conscious Building. His architectural & building experience covers historic & contemporary buildings, innovative/traditional materials & the development of built environment energy efficiency solutions. Simmonds.Mills Architects designs sustainable low-energy domestic & non-domestic projects to the AECB Silver, Passivhaus & EnerPHit energy standards. Simmonds.Mills have completed several certified Passivhaus Buildings & Andy’s family home in Hereford is an exemplar near-Passivhaus (EnerPHit) ‘whole house’ low energy refurbishment.

Andrew led the development of the AECB energy standards & initiated the AECB CarbonLite programme – including the AECB/TSB low energy buildings database & the CarbonLite Silver/Passivhaus/Gold detail design guidance. He also led the AECB team supporting the Technology Strategy Board’s ‘Retrofit for the Future’ competition, including developing the low energy buildings database, & worked with AECB colleagues, setting up the Passivhaus Trust to bring to the mainstream the work of AECB CarbonLite. He worked with David Olivier on the AECB commissioned report ‘Less is More – Energy Security after Oil’.

He talks widely on effective low energy building design and construction – & has become expert on best practice in moisture-robust energy efficiency retrofitting of different types of UK buildings – in the context of UK wide need for cost effective and practicable decarbonisation of heat and power.

We have all been involved in facilitating design workshops with both children and adults, and are committed to making the design and production of ecological buildings inclusive, empowering and fun! We are used to working with people with little experience of visualising designs from technical drawings, or of the pragmatics of buildings.

We have run training courses and seminars in earth building and timber use, and ecological and energy efficient building generally.