The relative sustainability of building materials – guides and sources

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

• Preblended concrete
• Structural and joinery timber
• Timber beams and joists
• Bricks
• Building blocks
• Building and walling stone
• Stone quarries
• Steel beams and columns

PassivHaus: the devil is in the detail

The PassivHaus concept is quite a simple one: create an airtight, super-insulated structure, install mechanical ventilation with heat recovery, address thermal bridging, and find yourself with a building that can essentially be heated by a hairdryer. However, as with most things, the devil is in the detail…

Here, I take a look at the following questions:

• What does a PassivHaus look like?
• What does a PassivHaus cost?
• What about air quality?
• Which products are used in a PassivHaus?
• What is it like like to live in a PassivHaus?
• What is the next big thing after PassivHaus?

What does a PassivHaus look like?

PassivHaus is really a design and build process, as opposed to a particular style of architecture. Whilst we may have preconceived ideas of a PassivHaus-certified building’s aesthetics, it could (at least in theory) look pretty much like anything – especially given that existing buildings can be retrofitted to PassivHaus standard.

100 Princedale Rd, Paul Davis + Partners

This was done at 100 Princedale Road – a Victorian house in a London conservation area – by Paul Davis + Partners and contractor Philip Proffit of Ryder Strategies Europe Ltd. This house was the first of its kind in the UK to achieve PassivHaus accreditation, meeting its target to reduce carbon emissions by 80%. (Granted, with the subject of the retrofit starting out as a drafty, four-story old house, there was plenty of scope for improvement.) In other words, a passive house can be anything from a large, new office building to a centuries-old, traditional house. Below are some examples:

Single-family residence in Brooklyn, NYC | Gregory Duncan

Eurogate Sozialbau, Vienna – Europe's largest PassivHaus settlement? | Tiger46 on Flickr

Passive house office building in Austria | Tõnu Mauring

What does a PassivHaus cost?

The Footprint article on the Princedale Road Retrofit for the Future project includes an interesting breakdown of the cost / payback time / bills before and after completion, making a comparison between refurbishing to PassivHaus or Decent Homes criteria. The Green Building Store, in conjunction with Building magazine, has also provided a breakdown of costs for the Denby Dale PassivHaus in West Yorkshire.

What about air quality?

The more passive (or other enclosed, airtight and sealed) houses we construct, the more important it is that we keep monitoring and assessing the quality of the air circulated in these buildings. Are we avoiding moisture build-up? Is the air too dry? Is there enough of it? Will we see a concentration of emissions inside these buildings, over time, from the building materials used? What are the potential positive/negative effects on occupants’ health and well-being? Housebuilder’s Bible author Mark Brinkley experiments with air quality and CO2 levels in this House 2.0 blog post, relating his findings to PassivHaus standards.

To ensure a good level of fresh air supply, most passive houses are ventilated and heated by mechanical ventilation with heat recovery (MVHR). Heat from the warm air that is being extracted is passed to the incoming fresh air through a heat exchanger – with the result that heat loss is minimised and heating costs are reduced. Ducting is an integral part of this: “Marion Baeli, the architect on the [Princedale Road] project, stressed that in a retrofit with MVHR, the coordination of ductwork requires considerable design attention, and should be integrated right from the start.” (Footprint)

Airflex Pro suspended ceiling ductwork installation (Airflow Developments on ESI.info)

Which products are used in a PassivHaus?

The PassivHaus Institut provides a list of certified building components, products and systems suitable for use in PassivHaus construction. Presumably, as this concept gains popularity and awareness, the list will grow. We have already looked at ventilation. Other important components are energy-efficient windows, airtight seals and thermal insulation.

But of course, a component is only as good as its installation. As well as architects who know how to design a successful PassivHaus, and manufacturers who can make products suitable for this type of construction, we need contractors with the right skills and experience. (PassiveHouse Builders, Passivhaus/LCC, Passive Development and Viking House are some of the firms I have come across.)

Project Green Home, Palo Alto | Mark Hogan

What is it like to live in a PassivHaus?

Bill Butcher, the construction manager of the Denby Dale house, kept a 17-instalment diary during the building process. But what happens post-occupancy? How does the building perform, and how does it shape the lives and behaviours of its occupants? In a separate post, I have taken a closer look at the realities of living in a PassiveHouse.

What is the next big thing after PassivHaus?

In the absence of a unified, international environmental standard for buildings, there is a certain amount of ‘competition’ between the different accreditations. There is no shortage of acronyms to choose from, and there are almost as many opinions on which accreditation makes the most sense as there are design-and-build professionals. (For a sensible take on PassivHaus vs the Code for Sustainable Homes, see “The Bout of the Decade” by Sustainable Homes.)

Andrew Holt heads the practice Architectopia in Norway, and also runs a course on sustainable architecture. He has worked extensively on PassivHaus developments. In an Arkitektnytt.no article, he talks about what the next big thing after PassivHaus might be. Mentioning BREEAM, zero-emission housing and “plus houses”, Andrew emphasises the importance of tailoring the standard to the individual project, using different tools to come up with a package that is fit for purpose. He comes to a refreshing conclusion (my translation):

What follows ‘after’ the PassivHaus standard should be a variety of different possibilities, so that our ambitions are based increasingly on the individual project and its local climate and conditions. This would facilitate greater innovation, creativity and cross-disciplinary co-operation. This approach demands a high level of competence within the project team.

An understanding of what the PassivHaus standard is, is a prerequisite for high-quality construction within the energy-efficiency sector. An understanding of what the PassivHaus standard isn’t, is a prerequisite for moving forwards.

PassivHaus office in Langenhart | Train.bird on Flickr

How to design a Passive House

If you are looking to get started in Passive House design, you probably already understand the concept, but if not, first take a look at The Realities of Living in a Passive House, where the theory and the reality are explored.

Below are some more useful links and resources for Passive House design, ranging from the planning and design side, to the fully realised, bricks-and-mortar (or should that be insulation-and-seals?) side of things.

The concept
• Mark Siddall of Devereux Architects explains how simple the PassivHaus concept is and why it ‘is arguably THE low energy, low carbon design standard’.

Specification
• BRE provides a simple comparison between the outline specification of the PassivHaus standard and UK new-build common practice. Notice the wide gap.
• Passive House Planning Package – a clearly structured design tool that can be used directly by architects and designers.
• The Passive house Construction Check List from the German PassivHaus institute makes it easier to reach certified passive house standards by listing the most important steps in the process, and particularly draw the attention to the quality control process that must accompany the passive house construction process.

Certification
The standards are voluntary but rigorous.
• BRE oversees the PCScheme (PassivHaus Certification for Certified Designers and Consultants).
• Three key tests are carried out- the first being an initial energy calculation carried out in the Passive House Planning Package by a passive house designer, resulting in a passive house assessment report.
• A blower door test in the US, sometimes referred to as pressure testing / air permeability testing in the UK. (more info from a UK provider of PH testing services)
• The final quality checks by a qualified PH Certifier, after which the project is certified as an approved passive house.

image courtesy of BASF. Neopor® insulation used in Hudson Passive House by Dennis Wedlick Architect LLC

Organisations
• The Passive House Institute in Darmstadt, Germany, founded by PassivHaus co-originator Professor Wolfgang Feist.
• BRE UK Passive House hub
• International Passive House Association.
• Passivhaus UK, part of the BRE.

Other resources
•The Passive House magazine
•PassiPedia is a website dedicated to PH definitions, technical details, knowledge, news, performance stats, residents’ experiences etc.
•Certified Passive house designer course

UK Projects
• Y Foel, passive house in Wales
• The Crossway Passivhaus, by Richard Hawkes and featured on Grand Designs. See also this article by the certifier.
• Tygh-Na-Cladach, the UKs first affordable passive housing, designed by Professor Gokay Deveci. Again, certified by SPHC.
• The Lime House at The Works, Ebbw Vale. A certified Passivhaus and part of the Welsh Future Homes Project. Further details on the BRE website

Spiral staircases – reaching dizzying heights

Spiral staircases used to show opulence and grandeur in period houses and the homes of aristocrats and royalty. Today they are found in homes and houses throughout the world, you can even buy “do-it-yourself” kits off the internet.

Structurally speaking, spiral staircases are curved around a central support column and have only one balustrade, whereas helical staircases have a curved structure with two balustrades.

There are many examples of fantastic spiral and helical staircases around the world, some even date as far back as the 1600′s.

Solar power and feed-in tariffs

A sunny day after the endless wet of August got me thinking about solar power.

Solar Energy System - Jeremy Levine Design on Flickr

In April 2010 the government introduced a feed-in tariff (FiT) to encourage low carbon electricity generation, particularly by organisations not traditionally associated with electricity generation. In effect the government was paying a generous fixed price for electricity being fed into the grid from small-scale renewables projects.

- Anaerobic digestion
- Hydro
- Micro-CHP
- Solar PV
- Wind

In February 2011 the government announced it wanted to reduce the incentives for large solar farms, although by targetting installations over 50kW in size this included larger rooftop installations on public and private buildings, as well larger field sites.

A reduction in the feed-in tariff from around 41 pence/kWh down to 19 pence/kWh (or less) for schemes completed after the 1st August 2011 has now been implemented.

Glasgow’s Riverside Museum & the Museum of Liverpool: money well spent?

History is now being housed in the most modern of buildings, but architectural excellence comes at a price. June saw the opening of internationally renowned architect Zaha Hadid’s first major public building in the UK, the Riverside Museum: Scotland’s Museum of Transport and Travel. And just last week, Tuesday 19^th July, The Museum of Liverpool, the largest newly built museum in the UK for over 100 years, opened its doors to the public.

I spent many an afternoon at Glasgow’s old and dilapidated transport museum with its brick industrial-style exterior and 1970s-inspired interior. The new building located on Pointhouse Quay at Glasgow Harbour retains that industrial warehouse feel, but with a much more contemporary aesthetic.

The tunnel-like structure opens at each end, making it “porous to its context on either side”, and connecting the city of Glasgow with the River Clyde. Historically, the site has been a ferry crossing since the middle ages, making it a fitting tribute to the transport relics housed inside.

Housing music: the Rockheim building

Norwegian practice Pir II are the architects behind Rockheim. The project, completed in 2009, saw a listed industrial building – a disused  flour warehouse from 1920 – turned into a vibrant exhibition centre for Norwegian rock and pop. Far from being a staid and static museum, the venue focuses on interactive events, hosting everything from gigs to guitar lessons, tutorials in mixing hip-hop loops, and dress-up karaoke sessions.

Rockheim, Brattøra (Photo: Rockheim/Geir Mogen)

The building has a stunning impact on the Trondheim harbour skyline. Architecturally, the old warehouse facade has been kept intact, although major structural changes have been made to the interior. The big crowd-pleaser, however, is the spectacular display-box that sits on top of the existing building.

Go and put another jumper on: strategic steps to a low-carbon UK

Halfway I hope... by ingermaaike2, on Flickr

Let’s start with a quick question.

The UK is currently committed to reducing its greenhouse gas emissions by at least what percentage by 2050, relative to 1990 levels?

[Answer at the bottom]

The Department of Energy and Climate Change has a section on its website relating to a low-carbon UK and the above commitment.

There’s a fascinating calculator tool that allows you to balance the UK’s energy demand with the energy supply and monitor the resultant greenhouse emissions.

It’s a bit like playing SimCity and other ‘strategic life-simulation computer games’.

—-

Consider what the average temperature of homes should be.

DECC reports that the mean internal temperature of UK homes during the winter months was 17.5°C in 2007 compared to 16°C in 1990 and 12°C in 1970. Historically, the temperature people choose to heat their homes at has increased over the years.

You’re offered various choices ranging from letting this growth trend continue to 20°C by 2030 through to reducing average internal temperatures to 1990 levels.

The commentary is amusingly sobering. ‘Householders can experience today’s levels of thermal comfort whilst also reducing energy demand by wearing warmer clothing or by heating the house in a smarter way.’

—-

Or how significantly should home insulation be improved.

This time your choices range from reducing leakiness by between 25 and 50%, with varying percentages of the existing housing stock being upgraded (floor insulation / cavity wall insulation / triple glazing) and all new houses being built to Energy Saving Trust or even PassivHaus standards.

The most stringent level would half the power required to maintain a given temperature, although this would be partially offset by a growing housing stock and any failure to reverse the trend towards warmer homes.

—-

And it goes on to cover how we heat our homes and businesses, the efficiency of our lighting and appliances, how we travel and how goods are moved around.

And then it’s on the supply side. How many nuclear power stations should there be? Or carbon capture and storage power stations? How many wind turbines? How much of the agricultural land should be devoted to growing biofuels? Should the numbers of methane-producing livestock be reduced? Have you considered harvesting marine algae?

And what level of energy security do we need? What do we need in reserve if there’s a cold snap or an incoming pipeline is closed down?

It’s actually quite difficult to do.

—-

There are also example pathways from experts and interested parties.

Everyone broadly agrees that demand needs to be reduced by around a third, which usually encompasses electrifying domestic transport, shifting up to 50% of freight off roads to electric railways, making planes more fuel efficient and building to PassivHaus standards.

It’s on the supply side that there are disagreements. Friends of the Earth achieves the 2050 target with no new nuclear or carbon capture and storage, and a heavy emphasis on onshore wind turbines, solar energy and geothermal electricity. Whilst the Energy Technologies Institute take a broader mix of supply sources, including 13 new nuclear power stations along with wind, wave and hydroelectric sources.

Have a look – it’s thought provoking.

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[80%. Which is a lot.]

Google Panda: the effect on your web searches

Are you familiar with Google’s new Panda algorithm? Recently introduced, it has changed the way Google responds when architects and other specifiers search for products and services. Intended to weed out low-quality websites from search results, it has also had a knock-on effect on websites that provide genuinely useful services to web users.

This is the time to make sure your website contains unique, relevant content – making it a destination site in itself. John Macrae, Head of Sales for our parent site ESI.info, explains how.

Eats shoots & leaves: the Panda algorithm (Stéfan on Flickr)

There are a lot of ‘directory’ sites. Many of them simply aggregate information that is already widely available, present it in a directory format (with varying degrees of practical information for the user), slap on a form of user interface and hope to attract traffic via search engine optimisation.

In most instances, they generate revenue by acting as a source of web traffic to companies that pay to have web links prominent on the site.

Google has quite rightly seen that many of these sites serve little useful purpose to web browsers. The proliferation of these sites can clog up search results pages and mean that original suppliers’ sites that deliver good relevant content are being pushed off the first few results pages.

It seems wholly beneficial to web browsers that Google has introduced a new algorithm to help people ‘find more high-quality sites in search’. This algorithm has been labelled Google Panda and is aimed at dealing with sites that aggregate information.

The algorithm has certainly reduced the ranking of some poor directories, but it also has hit sites that provide a more sophisticated service to users. Google will continue to refine their algorithm because it understands that some good sites will have been affected, and that a blanket approach simply can’t deliver their desired outcome. Still, the genuinely useful directory sites must act themselves to avoid being de-ranked by Google.

Directory sites need to update their image (Brenda Starr on Flickr)

There is no doubt that ‘directory’ sites must re-evaluate their quality. The poorest of sites will have a mountain to climb in order to pass muster according to Google’s ‘quality’ algorithm: they will have to invest heavily in order to develop unique content, change their business model, and come up with a new raison d’etre to present to their advertisers.  In the meantime they’ll have to spend on Google Adwords to have any tangible search engine presence!

Fighting the panda (Kudumomo on Flickr)

In the context of directory sites, quality will involve:

1. Unique content
Unique content on a directory site is tricky to achieve, since the site collates information on products that are already written about on a manufacturer’s site. However, the directory site does not have to simply regurgitate existing web content. Unique directory content can be achieved by presenting products from a 3rd party perspective, in order to deliver the pertinent information free of ‘corporate speak’. Web users want clear and easily digestible information, ideally presented from an independent viewpoint.

The directory can also ensure that its content is presented in a consistent style that will make information about similar products from different companies easily comparable.

Truly unique content will only come from editorial input.  This requires the ‘directory’ to have an editorial resource that genuinely understands the industry and its products and services, and can then generate meaningful content – for example, overviews of products that help users gain a clear understanding of the options, technologies and applications.

Manufacturers can also play a role in providing additional unique content if the site can become a forum for publishing technical articles and white papers; good quality, educational content.

(Google’s own guidelines recommend that web designers ‘create a useful, information-rich site and write pages that clearly and accurately describe your content’.)

2. User functionality
Google delivers relevant search results. The user then has to explore those results on their own – going through results from different companies, different websites, all with different ways of presenting information – there’s no further guidance or help from the search engine.

A high-quality directory site can help the user interrogate the marketplace:

• Search refinements: sub-setting results according to a combination of relevant parameters (size, weight, materials, cost, accreditation etc).
• Product comparison: similar products summarised side-by-side on a web page can be invaluable to users looking to arrive quickly at the information that’s right for them.
• Management of information: users should be able to store and manage relevant information, organising this information efficiently for future reference.
• Tools to help users take ‘next actions’: providing the user with efficient communication channels to suppliers, whether contacting them individually or many at a time.

3. Taxonomy
A mass of quality content is only useful if it is organised in a logical and clear taxonomy. This organisation requires a huge amount of discipline and a deep understanding of the nature of the content. It is essential to deliver a more sophisticated search-and-refine functionality that benefits users. Investment in skilled personnel and suitable software is the only way to get a taxonomy right.

Has Google thrown the baby out with the bathwater?

Some very good directories (that are already highly regarded by their users) have been affected by Google’s new algorithm – albeit less so than poorer directories. Google will refine their algorithm over time, but even the best directories will be forced to reassess their quality.

This might lead to a new generation of ‘directory’ sites. Those with vision – and sufficient intelligence and resource to deliver the quality required – will prosper. With better directories appearing prominently in relevant search results, the web user will ultimately benefit.

Better directories will also negate the search results issue in the longer term, because if a directory site is good enough it will become a primary web destination, i.e. the object of the search rather than a spin-off of the search.

This might especially be the case where a directory serves a specific market, for example the construction industry. Here, a directory can focus its attention on satisfying the needs of a particular type of user, and market itself to a clearly defined user group.

Search, compare and select: ESI.info

What about ESI.info?

Here at ESI we’ve known all along that web users want quality. The old mantra ‘Content is King’ continues to resonate true. Our challenge is to continue to develop original content, user tools and functionality so as to cement our place as a focus for suppliers and buyers within our marketplace.

Our site is a valuable resource for the industries we operate in; it is much more than a ‘directory’. We will work with Google’s algorithms because we want our site to be seen on the right search pages, but we are fully engaged with our own target users, developing our relationship with the right people so as to become a primary internet destination for them.

It is this close relationship and understanding of the market, along with a growing market awareness of our site’s quality content and functionality, that will generate traffic for our site and achieve our objective of connecting users with the right information as efficiently as possible.

Sports stadia and the need for meaning

The recent contretemps over what should happen to this (see picture) after the London 2012 Olympic Games have finished confirmed my worst suspicions regarding modern sporting arenas.

Olympic Stadium, London - tompagenet on Flickr

Two football clubs were the bidders. West Ham were prepared to keep the athletics track, whereas Tottenham planned to completely rebuild the site as a football stadium and redevelop the Crystal Palace athletics facility. West Ham won.

We spend c£550m on a new stadium and then debate whether we should knock it down afterwards and rebuild it. I mean …

Every Olympics and every World Cup brings more stadia that look much the same. They’re a bit like cars: 15 years ago they had boxy corners, whilst now it’s soft edges, swoops and curves. Identikit capital expenditure.

It might be sacriligeous to say but I can’t even get that excited by the Beijing National Stadium, aka the Bird’s Nest. But I do remember what happened there.

.curt. on Flickr

friskytuna on Flickr

A real stadium has soul. Its greatness comes not from its physical form, but from the store of memories we can draw upon. And inevitably the memories are to do with people. A stadium becomes great when it is remembered not as a place of concrete, steel or timber but as a place where remarkable things happened.