Posts Tagged ‘Thermal mass’

Set in stone: time travel at BGS Keyworth

04/07/2012

The recently opened Geological Walk at British Geological Survey’s headquarters in Keyworth near Nottingham crams three billion years of the Earth’s history into a beautiful, 130m long stone concourse. Stephen Parry (Mineralogist and Petrologist at the BGS) and Michael Heap (Managing Director of expert natural stone suppliers CED Ltd) did the time-walk with me.

An ammonite-bearing block of Portland limestone

Each step on the Geological Walk takes you 25 million years closer to the present day. What can we learn from this ambitious project? (more…)

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Shadows through sand: translucent concrete

17/02/2012

Concrete may have started out as a heavy, low-tech material, associated with architectural brutalism and 1960s high-rises. How times have changed… Already on the market, or half-way towards becoming commercially available, are concrete formulations with any number of surprising qualities.

Silhouette & sand dunes, by Daniel Oines on Flickr

These days, concrete can be lightweight, waterproof, recyclable, bendable, self-healing, and even (arguably) environmentally sound. And now, concrete – that most solid-sounding of building materials – can be translucent, too.

Here is how light-transmitting concrete is made: layer upon layer, ultrafine optical fibres are paralellised and distributed through a fine-grained concrete mix. When set, the concrete is cut and shaped into panels or tiles, which are then polished to the desired texture.

With structural performance indicators including a compressive strength of 49N/mm2 (MPa) and bending strength of 7.7N/mm2 (MPa), translucent concrete may be used as a load-bearing material.

Luccon concrete, supplied by NY Stone Manhattan (on interiordesign.net)

When used as part of an external wall or placed in front of a window, these concrete panels need no light source other than the natural daylight that is diffused through the solid surface. If the concrete is mounted internally in the shape of wall, floor or ceiling panels, artificial light sources can be used to create special effects.

As you can imagine, designers have started playing around with this concept and its various applications:

  • The optical fibres, backlit with coloured LEDs, create concrete walls that shimmer in different shades according to where you stand in a room.
  • Points of optical fibres in different diameters, distributed unevenly through a dark concrete panel, create the illusion of a starry night sky.
  • The light-transmitting fibres can be arranged into the shapes of logos, company names, symbols and signage.

Two companies involved in the development, manufacture and supply of translucent concrete:

LUCEM Lichtbeton

LUCEM LABEL tiles with custom logos, names and icons

LUCEM bar counter with coloured background lighting

LiTraCon™

Main entrance of Museum Cella Septichora, Hungary

Iberville Parish Veterans Memorial, Baton Rouge

More information can be found in this Gizmag article on light-transmitting concrete. And finally, here’s one that DIY’er Calvin Drews made earlier: a video on how to make your own light-transmitting concrete.

300 years of brick-making: the Chailey kiln

17/02/2012

In a world of mass-production and building products whose inherent sustainability is lost in the amount of air, sea or road-miles it takes to get them to site, it is (at the risk of sounding a little bit Luddite) comforting to know that some products have been made in the same way, in the same place, for centuries.

In 2011, the Chailey brick factory in the middle of the Sussex Weald (owned by Ibstock since 1996) celebrated 300 years of continuous, traditional brick-making.

The Chailey clamp in operation at night

Bricks from the Chailey kiln are still produced to an original recipe, which includes a blend of local Wealden clays from Ibstock’s own quarry. The stock bricks are fired in a traditional clamp (one of only three still in use in the UK), giving them distinctive textures and warm colours. All Chailey bricks are then sorted and packed by hand – although the craftsmen and stackers do not, presumably, wear this traditional garb every day:

Ibstock stackers at the Chailey site

Clay pipes, tiles, pottery and bricks have been made in and around South Chailey since 1711. Since 1792, successive generations of the Norman family owned and operated the factory until it was finally sold to Redland in 1959.

The Chailey factory has the capacity to manufacture approximately 14 million bricks per year using a soft mud moulding process. It also manufactures pavers and brick specials. This video on Ibstock’s website details the history of the Chailey site and shows the traditional, clamp-fired production process.

The fire hole at Chailey

The Bulmer Brick & Tile Co – specialists in purpose-made bricks for restoration and conservation projects – also make their bricks in accordance with time-honoured methods. Fired in a coal-burning down-draught kiln, their facings, rubbers and specials are made from London clays that have been dug from these Suffolk seams in a near-continuous line since Tudor times.

The Minter family: skills handed down through generations

Another building product largely unchanged through time is the traditional plain roofing tile, which has been made to a standard size since 1666 (when the Great Fire of London gave rise to product standards and building regulations). Historically – and for obvious reasons – factories for making bricks and tiles were sited right where the clay source occurred, and that’s where they remain.

Image by Hotblack on MorgueFile

The relative sustainability of building materials – guides and sources

06/12/2011

The trade associations, enthusiasts and lobbyists for different building materials are busy telling us how sustainable their material of choice is, and how it out-performs all others. Amongst the myriad claims, facts and figures, how can we establish which material is the most environmentally friendly?  And is that even the right question to ask?

Timber is a natural material and absorbs CO2 while it grows, steel is eminently recyclable, concrete is ideal for thermal mass construction, whereas bricks are durable and can be reclaimed.

Even if we discover which has the lowest embodied carbon, for example, we may not agree on what sustainability actually means. Are we talking about cradle-to-grave lifespans, economic viability, wildlife considerations, energy performance, aesthetic impact, recyclability – or even taking a holistic view of the building’s use and social sustainability within a local community?

In the absence of a unified framework of assessment and an agreement on relevant metrics, the debate will continue.

At the end of the day, each project needs its own, tailored assessment. A good designer will select from all options and choose what is fit for purpose, rather than become too attached – by habit or preference – to one material or another.

But in order to make that choice, we need a level-headed view of the facts available for each material, accompanied by real-life case studies. We also need to consult with people who are in the know about the different accreditations and codes, and can give an unbiased overview. Below are some sources that make a good start.

Codes and certifications: consultancy

  • Mel Starrs, Associate Director at PRP Architects, specialises in sustainability and green buildings. Her Elemental blog is full of useful information.
  • The CodeStore.co.uk has a directory of CSH consultants and assessors. Materials is number 3 on the Code’s list of 9 sustainable design criteria.
  • Jennifer Hardi works for the BRE’s Low Carbon Future team and is also part of the technical support team for the Energy Saving Trust’s Best Practice Helpline.
  • Bruno Miglio is a Leader of Global Materials Science at Arup. The team offers advice on the use of materials in engineering and architecture – from design to reuse or demolition.
  • The BRE’s Green Guide to Specification assesses building materials and components in terms of their environmental impact across their entire life cycle.

Concrete

This is Concrete showcases sustainable construction projects and encourages project-based feedback, presenting case study evidence to support the sustainability credentials of concrete.

Sustainable Concrete has information on concrete production, performance and end-use, and provides indicators on materials efficiency.

MPA (Mineral Products Association) runs the Concrete Centre, which contains news, publications, webcasts, online services, advice and design tools.

Steel

The BCSA is the national organisation for the steel construction industry. Its website, SteelConstruction.org, has a section dedicated to sustainability. The BCSA’s Target Zero project “will generate costed solutions for structural steel framed construction that achieves highest BREEAM ratings and changes to Part L of the Building Regulations, meeting emissions reduction targets towards zero carbon by 2019.”

Timber

TRADA has a library of downloads that detail the sustainability of timber. The Association’s Technology Assessed scheme also helps establish whether a company’s literature gives a fair representation of the benefits and characteristics of a product or service – a useful tool against greenwash.

The Forestry Commission also provides comprehensive facts and figures on the timber trade.

Stone

All members of the Stone Federation of Great Britain have to comply with this Sustainability Statement. The Federation provides a Technical Advice Service for the commercial and domestic use of natural stone.

Stephen Critchley – a Master Stonemason in Central London – is a font of knowledge on ancient and modern uses of natural stone, giving talks, workshops and demonstrations.

The simplest view of the sustainability of natural stone – there is tonnes of it about and it lasts for a very long time – is outlined here by CED.

Bricks and blocks

Bricks, in the words of the Brick Development Association, are “a versatile and durable building material, with excellent life cycle performance, energy efficiency, high thermal mass and responsible manufacturing.” Its publications on the sustainability issues of bricks and brickwork are listed here.

Sustainable Build details the manufacture and use of bricks as a sustainable building material in this article, and also comments on stone vs brick.

What other sources have you found useful for determining the sustainability of specific building materials? Please leave a comment and let me know!

This post was inspired by an interesting conversation on Twitter with structural engineers David Sharpe and James Thomson.

Compare and select building materials on ESI.info

Breton architecture – a sense of place

06/08/2010

Paul Gauguin painted in Pont-Aven, moving from Impressionism to "synthetism"

Staring at the dreich, Scottish rain outside my office window, it is hard to believe that I have just come back from two sun-drenched weeks in Brittany.

I am trying to recall the sights, sounds and smells of Nevez, Raguenéz, Pont-Aven and Bénodet: the rough granite coastline and shimmering sea, the super-salty surf that the kids were gleefully dodging, the sudden and short-lived rainfalls drumming onto the roof of our tent. (Not to mention the local cider and caramel au beurre salée…)

A windy walk along the beach in Bénodet

Houses on the hill in Pont-Aven

I was struck by how closely the area’s many new-build houses resemble centuries-old Breton homes. While introducing some new features (maritime-style, circular windows were popular), the designs stayed close to the regional vernacular.

The buildings were  tall, wide and shallow structures, with thick masonry walls in white or cream render – good thermal mass for keeping warm in stormy winters and cool in blistering summers.

Windows were often small and placed mainly on south-facing facades, and roofs were steeply pitched slate or thatch with elaborate dormer window detailing. Gardens had sparse planting, clusters of pine, and the ubiquitous pink-and-blue hydrangea.

From Dol-de-Bretagne (Wikimedia Commons)

I assumed this uniformity to be a result of tight planning regulations – or is it self-enforced by Breton clients, architects and builders? Either way, the distinct architectural style helps preserve and reinforce the region’s identity.

Nevez cottages (Breizh33 on Flickr)

As much as I hate seeing innovative, brave design being stifled by overly conservative planning control (and royal interference…), I do enjoy spending time in places where new-builds retain a sense of history and local context. A difficult balance to strike, perhaps. Do you have any examples of places where they have got it right?

Maria (11) setting up 'home' in a big Breton pine

Darwin cocoon wins Concrete Society award

18/11/2009

The world's largest curved, sprayed concrete structure

The Darwin Centre Phase 2 forms part of the western extension of the Natural History Museum.

It provides a climate-controlled home for 20 million plant and insect specimens.

It also creates a working space for research scientists, as well as an exciting visitor destination.

Designed by Danish architects C F Møller, the cocoon was declared Overall Winner at the recent Concrete Society’s Awards for Excellence ceremony.

Judges said the structure will become “a benchmark for the production of extreme shapes in concrete”.

The extension contrasts with the original 19th century building

ESI references: