SUSTAINABLE STRUCTURAL MATERIALS AND FORMS

The appropriate use of renewable and sustainable building materials is central to Corbett and Tasker's practice. David Tasker has been a visiting lecturer and consultant to the Centre for Alternative Technology (CAT) over many years, gaining experience of a wide range of green structural materials and Peter has worked with major international retailers advising them how to reduce the carbon embodied in their buildings. Many of our projects have gone on to win major awards them how to reduce the carbon embodied in their buildings. Many of our projects have gone on to win major awards for Sustainability, including the Sustainable Building of the Year from the UK Green Building Council.

We have a sufficient grounding in many sustainable materials and construction techniques to be able to assess their relative merits and to be develop viable, efficient structural designs for selected materials and forms, and have written numerous papers on their application within our projects.

Timber

Timber is probably our most often used structural material; besides the usual softwood and laminated beams we have engineered structures using timber in the round, green oak, and thinnings used as gridshells. We have a particular expertise in the use of Cross Laminated Timber (CLT) as floors and walls and have recently designed a highly efficient folded plate roofs in this material. As well as CLT we have extensive experience in the structural use of Structural Insulated Panels (SIPs) for thermally efficient building envelopes and minimal material usage.

Lime
As a more sustainable alternative to Portland cement, we have used lime as a mortar for masonry and as the active constituent with sand and aggregates for limecrete. We have recently completed a series of lightweight timber structures constructed in woodland using limecrete footings located to avoid tree roots.

Straw Bale
David has worked with Barbara Jones, experiencing straw bale construction first hand on a farm building store in Yorkshire; with Christopher Day, he engineered a series of straw bale buildings in Fresno California.

Rammed Earth
Working with Rowland Keable, David has undertaken the design development of a number of rammed earth walls and has reviewed and monitored the extensive rammed earth walls at the Centre for Alternative Technology. 

Hempcrete
We have been researching this material for many years and have reviewed the test sample panels at CAT where it is used as an infill material within a timber stud frame. We have been particularly interested in the use of Hempcrete as a roof vaulting material and have reviewed David Lea’s experimental Hempcrete structures at the Welsh School of Architecture.

Masonry Vaulting
We have been carefully monitoring and keeping abreast of recent developments in the field of tile vaulting using engineering construction techniques developed from Guastavino. Of particular interest is the work of Block in Switzerland and Peter Rich in South Africa. 

Cardboard
David has designed and constructed a number of geodesic and polyhedral structures using surface protected tri-wall cardboard; a building system was devised for Oxfam to be used for emergency housing.

Recycled Materials
We always seek to maximise the use of recycled and responsibly sourced materials in our buildings where appropriate, including the use of GGBS and PFA cement replacement for concrete elements, recycled aggregate blockwork unfired clay bricks and recycled glass and desulpherised gypsum used as binders in screeds. Many of these materials are by-products from industrial processes which may otherwise go to waste.