Passivhaus Affiliate

Standard Members

Cambridge Architectural Research


CaSA Architects Ltd


CaSA Architects is an award-winning RIBA chartered design practice with a passion for original contemporary architecture using proven sustainable principles. We deliver carefully considered, bespoke solutions derived from a thorough understanding of our clients and tailored very specifically to them and the site. Quality is at the centre of our approach, inspiring and informing everything we do. Our work is principally in the private housing sector, but also includes education and community. We have experience applying Passivhaus principles to a range of building types, incorporating a fabric first approach. We have recently completed a pair of RIBA award winning community buildings in Hampshire built to Passivhaus standards. See our website for details


Cayford Design


Cayford Design. Certified Passivhaus Designers, creating inspiring environments and buildings for well-being, creativity and productivity. RIBA Chartered Practice


CBG Consultants



CLC International (CASFAS Ltd)


With interests in both the Caribbean and London, CLC International offer construction, property development and management services. Our interest in eco building stemmed from working on a new Passivhaus home designed by a renowned, London architect, with a special interest in Passivhaus design. As a company, we have now re-aligned our goals towards the Passivhaus standard, and hope to use our influence and experience to work with progressive architects to deliver exciting and ground-breaking projects around the UK and beyond. We believe it is our responsibility as representatives of the building community, to ensure that we promote Passivhaus technology to all as the standard for building in the 21st century.


Cocreate Consulting


Cocreate are an accredited Passivhaus Certifier. We can help you achieve the Passivhaus standard and provide design advice to help architects, developers, and engineers improve the comfort and reduce the environmental impact of buildings over the long term - saving on operating and asset costs in the process. We help clients set the right specification, help contractors achieve the required standards, and offer training to professional teams to build understanding and improve decision making.




ColdProof is run by Eric Fewster, a Chartered Environmentalist and Certified Passive House Consultant. He specializes in using Passive House methodology and thermal bridge modelling to analyse and plan whole house retrofit projects for existing houses – this includes not only the energy analysis that enables homeowners to reach specific space heating demand or carbon emissions reduction targets, but also a practical plan of action which includes MVHR design, material specification, bill of quantities, economic analysis and work sequencing. This is all arrived at through several trial runs in which scenarios for improvements are honed according to the available budget - all done in consultation with the homeowner. He also can act as retrofit coordinator in certain cases.


Comfort Being Ltd


Conker Conservation Ltd


Chartered building surveyors specialising in sustainable design, new-build, conversions, refurbishment and historic building conservation. A family business established in 1999 with experience in using modern and traditional methods of construction including rammed chalk, rammed earth, straw bales, timbrel vaulting (creating large span domes without formwork using clay tiles), super-insulated masonry and timber frame. Working with Passivhaus standard since 2005. We work mainly in the south east on residential, commercial and education projects. We are nuts about sustainability.


Constructive Individuals


Constructive Individuals is a York-based practice run by architect and Certified Passivhaus Designer Phil Bixby. The practice brings to projects over 25 years of experience in working with communities and individuals to enable them to decide, design and build. Past projects have included community self-build and self-help projects, sustainable social and individual housing, and extensive work with children and young people. We have worked as architects, project managers and training consultants, and aim to work WITH clients, rather than simply FOR them.


Cowan Architects

East Grinstead

Cowan Eco Design, part of Cowan Architects, is led by Mark Elton who has been responsible for numerous exemplary new-build and refurbishment, low-carbon projects over the last 20 years. Cowan Architects has established itself over 33 years with a reputation in residential care homes and housing, including a particular expertise in inclusive design. This brings a good correlation between these sectors and the health and well-being benefits of the Passivhaus approach. With London and Sussex offices, Cowan Eco Design covers the south of the UK with particular interests in residential and community projects, including retrofit to the EnerPHit standard.



Julian is a chartered building services engineer and Fellow of CIBSE with a specialism in sustainable/environmental building design, client design advice and low carbon master planning. He has 27 years of experience. Projects include the Royal Ontario Museum in Toronto, Tower Place in London, the Parkview Battersea Power Station scheme. He has recently completed his own certified Passivhaus in Hampshire and is a regular judge for the Construction News Awards and the RIBA sustainable building award. In 2016 he chaired the UKGBC task group – delivering Building Performance.


CVC Direct


CVC Direct Ltd are distributors for Brink Climate Systems, the leading manufacturer in Europe of Passivhaus certified MVHR units with constant flow motors. This series of low energy MVHR units, several of which are available with an A+ ErP energy rating, offer a range of solutions including demand controlled ventilation. The Brink units are noted for the sophisticated design with a large range of operating parameters yet simple to install and commission as the air flows can be programmed with the digital controls. Years of experience means our designers can offer informed advice and innovative solutions for domestic ventilation installations. Brink MVHR units, when used in combination with our easy-to-install radial ducting, can ensure low energy, low noise, and no leak heat recovery ventilation systems. CVC Direct carry stock of both the Brink MVHR units and complete radial ducting systems for next day delivery.

Cygnum Timber Frame Ltd


Established in 1996, Cygnum is a leading supplier of timber frame structures in the UK and Ireland. Cygnum’s Passive 350 building system received Passive House certification in December 2013. Some of our key technical staff are qualified Passive House designers and we have been the selected timber frame supplier on many Certified Passive House and near Passive House buildings including the award winning Oakmeadow school in Wolverhampton. More recently Cygnum have been awarded the contract to design supply and install the timber frame structure, glulam frame, cellulose insulation and airtightness layer for the high profile University of East Anglia Exemplary Low Carbon Building Project at Norwich Research Park.