sustain by design is a multi-disciplinary architectural practice with its roots going back to the 80's,

but its eye very much on 2050 and beyond - and the need to address climate change.

what we do is design buildings and places... for people.

why sustain by design ?

the power of design... to sustain... life, soul, activity, by... quality, integrity, beauty

the power to sustain... the eco-system of which we are part... by conserving energy, water, CO2... using local + beneficial materials

sustainable development - an oxymoron ?

“Ensure that it meets the needs of the present without compromising the ability of future generations to meet their own needs.” Brundtland report, 1987

current + recent work

major new multi-use development, coleford, glos - in design development


new eco-house, carmarthenshire - submitted for planning


new houses, newport - in design development


2 new eco-houses, abergavenny - nearing completion on site

enerPHit barn conversion, crickhowell - completed 2016


low energy barn conversion, monmouth - completed 2016


replacement dwelling, monmouth - completed 2015


grade II* listed house alterations, herefordshire - ongoing

listed extension, monmouth - completed 2014


multi-barn complex, hartpury, glos - first stage completed 2014


solar pv parks, south wales -completed 2013


self-build code 3 houses, hereford - completed 2012

eco-barn conversion, ross-on-wye


eco-studio new-build, ross-on-wye


listed mill conversion, monmouthshire


low energy business park, coleford

enerPHit barn conversion, crickhowell >

We converted the grade 11 listed Long Barn, Gilwern, to a two-family four-generation family home... for ourselves.

The project, completed in 2016, features:

  • design to passivhaus enerPHit standard, currently under performance monitoring

  • highly insulated + airtight timber-frame house built within thick stone walls

  • MVHR system for comfort ventilation and heat recovery

  • triple-glazed doors and windows

  • 2 atria spaces  

We are proud of the project, and happy to provide 'warts-and-all' guided tours.

key words




eco architects

eco design




passive house


barn conversions

new build

self build

listed buildings



monmouth architect

monmouth eco architect


monmouthshire architect

monmouthshire eco architect


hereford architect

hereford eco architect


herefordshire architect

herefordshire eco architect


ross architect

ross eco architect


gloucestershire architect

gloucestershire eco architect

forest of dean

forest of dean architect

forest of dean eco architect

brecon beacons

brecon beacons architect 

brecon beacons eco architect


powys architect

powys eco architect

south wales

south wales architect

south wales eco architect

listed extension, nr. monmouth | 2014

the modern extension design has been carefully considered to complement the listed victorian coach house

barn conversions, hartpury, glos | 2014


we have been working for a while on this project to convert a

group of barns near hartpury, glos, to low energy dwellings.

the design is underlaid by a planning approval from 1998.

the first barn dwelling conversion was approved in late 2011. 

the building regs. approval was very rapid. 


thermal modelling predicts space-and water-heating costs of 

£200-300 using a new wood pellet boiler and underfloor heating

designing super-insulation for such buildings is a particular

challenge, but perfectly possible

kitchen extension, builth wells | 2013

a recently designed kitchen extension for an isolated

mid-wales cottage with 16th or 17th century origins.

the design needed to respond to the existing building

while providing 21st century facilities for the owners

it maximises the stunning views and  passive solar gain

to the south whilst providing high levels of insulation

to the north, along with a new bio-mass + solar heating system

the building control approval took one working day

surely a record ?


listed mill conversion | 2012

showing the diversity of our work, this collection of listed buildings has been

converted for residential and teaching use.

the 19th century water mill with its own [now defunct] 2km long mill-race,

has been turned into visitor accommodation, whilst the associated studio

and cottage buildings have been sensitively improved


the listed status required detailed negotiation with the LPA conservation

officers - not always a speedy or easy process - resulting in a commendable

adaptation of worthy historic buildings


our experience of housing work covers the full range of provision - from

domestic extensions and refurbishments to multi-million pound schemes,




swansea student housing [with Architype] 2006 | 5.4m

276 units of en-suite accommodation for swansea university.

smaller housing developments 

including pioneers self-build, gloucestershire, an innovative low-energy

post-and-beam timber-framed scheme of 8 houses - originated by dean

design, and project managed for gloucestershire housing association in 1994 


private houses 

individual and small housing groups, barn conversions, extensions + renovations

- hundreds of completed schemes over 35 years.


guardian courtyard, coleford, glos | 2006

10 houses and apartments for older people designed to

use a brown-field site on the edge of a historic town centre

Including the proposed conversion and extension of a grade

II listed building, required archaeological explorations, and

carefully designed suds scheme | not yet built


pioneers self-build, gloucestershire | 1994

an innovative low-energy post-and-beam timber-framed

scheme of 8 houses, this was originated by dean design,

and project managed for a local housing association.

code 3 houses, hereford | 2010

2 spec. houses designed for a select site on the edge of

hereford city, with southern views over the wye valley.

self-built by individual families | c.2010

private houses

nissel house, st briavels, glos | 1990,1995,2014

a highly insulated replacement 3 bedroom dwelling,

with slate + stone + oak, open-plan,

built 1990, extended in 1995 + again in 2014  







barn conversion, tibberton, glos | 1990

conversion of victorian timber-framed

barn to a luxury 500m2 house

extension + renovation, soudley, glos | 1985

compact two-storey lean-to  extension to

forest of dean cottage. highly insulated for the time.

swansea student housing | 2004 | 5.4m

276 units of en-suite accommodation for swansea university completed while with architype.

simon managed the planning, and design development of this innovative 7/8 storey timber-framed build. 

the site layout required careful planning around:

- existing protected trees

- a neighbouring listed park +

- existing 10-storey 60‘s tower blocks

the layout of each block was simple + elegant, allowing single stair + lift access, whilst ensuring clear visibility of all flats, and natural daylighting of each short corridor 

the scheme  featured high levels  of insulation + daylighting


miners welfare hall, cinderford, glos. | 1998

feasibility work for a £1m refurbishment for a valued local asset, funded by miners’ penny-a-week subscriptions 


belle vue centre, cinderford, glos | 1992 | 750k

detailed feasibility, project management + design of innovative community business centre for town council

brunston surgery, coleford, glos | 1993 | 150k

innovative circular surgery featuring low-energy design, high natural daylighting, recycled stone facing 








united reform church, broadway, worcs |2008

feasibility work for a major expansion of facilities 



interpretation centre, worcester | 2001 | 3m

feasibility study for landmark visitor centre to revive existing country park. with architype 


belle vue centre, cinderford, glos | 2003

this 'community business centre' has now paid back its loan finance, and is contributing to the revenue finances  of its town council owners.













waste wood-powered heat + power plant, monmouth

this scheme was planned to provide 6MW of electricity, heat + other facilities for monmouth

value ± £15m 




stepbridge enterprise park, coleford, gloucestershire 

high quality private business park