Building With Straw Bales

Chapter 2

AFFORDABLE HOUSES WITH LOW ENVIRONMENTAL IMPACT

Quality and affordability

The environment we live in affects our moods and the way we feel. It can make us feel confident, optimistic and motivated or demoralised, downtrodden and hopeless. When buying a house, the question ‘What would I feel like if I lived in this house?’ isn’t usually the first one we ask – it’s more likely to be ‘Can I afford it?’ We don’t ask whether the house will help us to grow, to be purposeful, to contribute to society, or whether it will make us feel small and mean. Imagine what our world would feel like if our homes were full of positive, optimistic and creative energy! Although we have the power to change things, and the ability to make choices, these can often feel severely limited by a culture dominated by financial imperatives rather than principles of wellbeing or contentment. It can be hard to envision a world for ourselves that nurtures and sustains us. But why should we accept anything less?

Feeling good is vitally important to wellbeing, but it is not taken into account within construction. If we build homes that people love then the people who inhabit them will want to look after them and preserve them. How things are built, the energy and the intention with which they are built, becomes part of the fabric of that building. The way our construction industry operates does not take feelings and processes into account, which have an impact on quality; it values only function and economics. The system of piecework on building sites, where workers are paid by the number of jobs they complete, or the use of subcontractors who submit low quotes just to win contracts, encourages poor-quality work as each tries to work faster and cuts corners to earn more money. Competitive tendering has the same effect: companies are encouraged to submit the lowest price possible in order to win a contract, and then have to build as fast as possible with the cheapest materials in order to stay within the quoted price. Manual skills are not valued, training is not taken seriously, and the industry is not proud of itself.

Building cheaply does not benefit any of us in the long run, but we have been forced into a narrow view of choice, where our own well-being is secondary to financial implications. Choices are restricted by the limited range of what’s on offer. Short-term savings cost us more in the end, because mediocre building makes us all unhappy and dissatisfied, and unhappy people can be disruptive for the rest of society – plus the buildings themselves are not durable. We are making do with what’s available when we could be creating places to live and work that actually increase our sense of belonging in the world; that give us a centred space to begin from each day and return to at night.

This limited perception of choice, between affordability and quality, is flawed. It is absolutely possible to incorporate a more positive value system into the construction industry and still build affordable houses, as is being proved through the development of strawbale and natural house building. Affordable houses are now being built, to very high standards of thermal efficiency, without compromising on quality and while providing a beautiful, organic ambience to the house that increases well-being.

It is absolutely possible to incorporate a more positive value system into the construction industry and still build affordable houses, as is being proved through the development of strawbale and natural house building.

It is now possible to build a thermally efficient three-bedroomed strawbale house for £100,000, with the involvement of people who will live in and around it, which will last upwards of 200 years – and this price will drop as more are built. This cost is for a house built by a contractor; if you do some of it yourself or with friends, and run courses to teach people the skills at the same time as building, then you can make further savings. This is on top of the longterm savings to be made on heating bills, as described in Chapter 1. In fact, with good design, it’s possible to build a strawbale house that has no or almost no need for heating. In years to come this will be an increasingly desirable feature that will make your strawbale home more attractive to buy than similar houses in the same area.

In mainstream construction, it’s possible to build a modern brick-and-block house for £700-850/m² (£65-80/ft²), giving a price of £70,000-85,000 for a three-bedroomed house. However, it is not fair to compare such a house with the strawbale houses currently being built, in terms of thermal efficiency, comfort and durability – we have to compare like with like. In order to build a modern house that matched the insulation values and quality of a strawbale house, the price would increase well beyond the £100,000 mark. This is why the construction industry is complaining that government targets for affordable but sustainable houses are not achievable, and they aren’t achievable by using current mainstream materials. We need a radical change!

Designs for such houses have been developed over the last few years by amazonails, incorporating the features described below. The first house to be built like this is at Ralegh’s Cross Inn in Exmoor: a two-storey, semi-detached, loadbearing strawbale house for hotel staff. North Kesteven Council in Lincolnshire is the first local authority to build social housing out of straw: this is another two-storey, semi-detached, loadbearing straw building comprising two three-bedroomed semis. These buildings are leading the way in bringing the cost of desirable home ownership within the reach of the ordinary person again.

Keeping costs down

If we are to accept the challenge of building affordable homes then we have to radically rethink the way we build, and using the current cavity-wall system is not the way to go: it’s a really bad design that has never worked well in practice, and the materials used to construct it are not sustainable. Tinkering about with this system can bring only minor changes in cost, and won’t give us the thermal efficiency that we need for the twenty-first century – and that’s without taking into consideration the feel of the homes inside. At the moment, the construction industry seems to be content to rely on outdated systems and add-ons and still fails to meet government targets. We need a complete rethink of how we build houses. We have to be more creative!

An affordable house is achieved by a combination of factors, described below.

Simplicity of design

The more you add quirky little bits to your building – unusual shapes, different levels of roof pitch, even curves; in fact most things that make your house really quite an individual home – the price will go up if you’re having it built for you or buying it off the peg, because all these things take extra time or extra materials. It’s a shame, but it’s true that a basic box is cheaper to build than a beautiful circular house. This is partly to do with the fact that modern building materials come in basic box-sized shapes, so when you try to make them into curves there is a lot of wastage. It’s true that the standardisation of materials has come about as a result of trying to make the construction process cheaper, but with that impetus we’ve also lost the ability to make our homes individual and beautiful and truly ours.

Often the simplest houses are the most beautiful. Look at a typical cob (earthwalled) long-house: thick walls, rectangular structure, with proportions that resonate subconsciously in the human psyche, reflecting the geometry found everywhere in the natural world – the reason why some buildings are more pleasing to us than others. These houses sell at a premium, they last upwards of 400 years, they have an organic feel to them and they have a quality of atmosphere that is hard to describe but feels safe, cosy and pleasing. They were built by lots of people coming together to help, with natural materials, and to designs that were tried and tested. In fact, they sound very similar to modern strawbale houses! We can keep costs down by designing houses that are simple to build from a practical point of view, are made of readily available and common materials, use accessible construction methods, and have an internal design that’s well-thought-out and relevant to modern lifestyles – such as being open plan so that heat can circulate easily around the house.

Local and natural materials with low embodied energy

Another way to keep building costs down is to use materials that don’t cost the Earth.The more highly processed a material is and the further it has to travel to your building site, the more it will cost, both environmentally and financially. The closer it remains to its natural state, the cheaper (and healthier) it will be. In one sense building a strawbale house may only mean changing the wall system from a typical brick-and-block cavity to using straw, but why stop there? Eightyfive per cent of the materials in a typical amazonails-designed strawbale house are natural, with low embodied energy. These buildings use no cement at all, not even in the foundations, require no plastic dampproof courses, and use sheepswool, hemp and wood fibre, lime and clay, and durable and small-dimension timber.

If you compare the embodied energy (measured in kWh/m²) of 1m² of a standard amazonails straw wall (loadbearing straw bales rendered externally with lime and plastered internally with clay) with that of 1m² of a standard modern wall (brick, lightweight block, mineral fibre insulation, gypsum plaster) of approximately equal superinsulation (to make the comparison of like with like), the results are as follows. (From the MSc thesis of Carol Atkinson, who has built her own mobile strawbale holiday home at Howden, East Yorkshire, on which she carried out extensive research.*)

1m² of standard strawbale wall	36.5kWh/m²
1m² of cavity wall insulated with mineral-fibre insulation	172kWh/m²

Clearly there is no comparison! These results are so good that at the moment, most people working in the construction industry are not able to accept them (it’s a bit like talking a foreign language – it’s so different, it doesn’t make sense at first).

Accessible building methods

Another way of keeping building costs down is to help with the building yourself, and get your friends and family to join in. This is possible with strawbale building because the methods of construction are simple and straightforward, and there are no hidden technologies. And the money saved on the labour costs will mean you can afford to be more creative with your design choices.

You can help with the building yourself, and get your friends and family to join in. Strawbale building methods of construction are simple and straightforward, and there are no hidden technologies.

Many self-builders have been able to afford ‘designer’-type houses, because they have put in their own time and effort over a number of years, worked more slowly with volunteers and by running courses, and taken time to find reusable and recycled materials. Increasingly, we are pioneering this process on mainstream construction sites as well, working with main contractors and running courses on-site for the public, the builders and the intended users of the building. Working with large straw blocks to put up walls with your friends is fast, effective and fun! There are very few people who are not able to build using straw, and strawbale building sites commonly include younger and older people, and people with a diversity of talent and experience. This alternative approach to building has the long-term benefit that people feel happier if they are involved in their own building; they feel a sense of ownership and identify with it.

Open accounting systems and partnership working

Whatever happened to trust? Being worried and fearful about finances and the integrity of your colleagues can completely destroy trust. We live in a culture of fear rather than trust; we’re encouraged to expect the worst rather than the best, to insure against our fears and generally protect ourselves just in case; inhabiting a more and more frightened and insular world. We need to learn how to rely on ourselves and our friends again, to build networks and support each other. A system built on fear and self-interest is bound to topple in the end because greed demands that there is always more to be had. The essence of sustainability is to use what is enough, and no more. We need to learn to be satisfied with what we have, to recognise worth when we find it, and to stop trying to get more and more and more! This is not life-enhancing.

We need to be able to trust our builders, and they need to convince us that they will work hard, uphold high standards of quality and work, and can be left alone in our homes without our worrying about safety. The industry needs to be able to trust the client, to know that we are willing to pay a fair price for a job well done, and that we will be honest and just in our dealings with those we contract. If this atmosphere of trust existed then we could also have a reasonable discussion about accounting; about how much things cost, what is a fair price for the job, and sharing the profit if all goes really well (or the loss if something goes wrong). There would be no need for competitive tendering, and all its associated costs – work could be shared around with a price agreed at commencement.

If we are able to communicate well, speak with clarity and listen attentively; if we can bring honesty and integrity to the discussion table; if we’re willing to trust each other, take risks, work together and learn from mistakes, then we are opening up the boundaries of possibility. If we believe that we all want to create the best building possible, and that different perspectives can actually help achieve this, then working in partnership has got to be the way forward. The more you believe in somebody the more they excel. The feeling of all being in this together, working for a common aim, is a feature of many strawbale builds. There are many ways in which we find we are interdependent and need to rely on each other. It focuses the mind and allows for innovation.

Is there enough straw?

If we were to build all the houses we are told we need each year, would there be enough straw, and would we have to use more land to produce it? The table opposite shows recent wheat-straw production in England, and its uses.

Even in a bad year, when there was a lot of rain that ruined the harvest, we still produced 2.37 million tonnes of straw that had no other use than to be ploughed back in. If a standard three-bedroomed house takes 350 bales to build, then this amount of straw can build approximately 423,000 houses. So clearly the answer is yes, there’s more than enough straw, and no, we wouldn’t have to use more land to produce it, we’d just have to stop ploughing some of it in. This practice began after the law changed and surplus straw could no longer be burnt.

	Wheat straw (million tonnes)				All cereals (million tonnes)
	Area (hectares)	Total	Ploughed back in (40%)	Baled for farm use (30%)	Baled for sale (30%)	Area (hectares)	Total
2007	1,690,984	5.92	2.37	1.78	1.78	2,393,073	8.38
2006	1,709,042	5.98	2.39	1.79	1.79	2,387,691	8.36
2005	1,748,414	6.12	2.45	1.84	1.84	2,429,363	8.50
2004	1,865,163	6.53	2.61	1.96	1.96	2,609,459	9.13
2003	1,726,563	6.04	2.42	1.81	1.81	2,543,048	8.90

Source: Defra 2007

Straw houses and carbon footprint

The Carbon Trust defines a carbon footprint as ‘the total set of greenhouse gas emissions caused directly and indirectly by an [individual, event, organisation, product], expressed as CO₂e [carbon dioxide equivalent].’

Almost all houses have a positive carbon footprint because of the materials they are built with. If you took all the materials used in their construction into account and analysed how much CO₂ was produced or sequestered (stored) by them inherently, or produced during their manufacturing process by the use of energy that emitted CO₂, or produced as a result of transportation associated with them, it would show that they are responsible for the release of far more CO₂ into the atmosphere than any that they might store. The government is encouraging the construction industry to achieve a zero carbon footprint, but we can achieve a resoundingly negative footprint very easily by using a completely different approach to building walls.

Houses built of naturally grown materials, e.g. straw, wood, hemp, newspaper (for insulation), etc., are totally different because they are made up of materials that have been grown in the earth, and as all plants take in CO₂ from the atmosphere and release oxygen, they all store CO₂ and have a negative carbon footprint by their very nature.

The figure opposite shows 25 common materials and their CO₂ pollution. You’ll see that the worst polluters are the metals, because they take an enormous amount of energy to extract from the earth. Fortunately, we use them in only small quantities, so their contribution to our carbon footprint is minimal. Cement, on the other hand, seems fairly average and on a par with plywood, until we realise just how much of this material we use. Next to water and sand it is the most-used commodity globally, so it becomes probably the single most damaging polluter in the world. If you look at where cement factories are situated – right next to electricity-generating plants – this gives you a clue as to just how much electricity is used to make it. They would put too much strain on our system if they were further away! Most of the plant materials, on the other hand, are non-polluters except for the highly processed ones.

According to Carol Atkinson, the average UK home produces 50 tonnes of CO₂ during its construction. In contrast, research by Jakub Wihan, in his thesis Humidity in Straw Bale Walls and its Effect on the Decomposition of Straw (see Appendix 1 for more on this subject) shows that one 16kg straw bale stores 32kg of CO₂. Since it takes about 350 bales to build a typical three-bedroomed house, this type of building will store roughly 11.2 tonnes of CO2 in its fabric.

This three-bedroomed strawbale house, built in 2000, will lock up carbon for the lifetime of the building-expected to be at 200 years, photograph Bee Rowan

Net CO₂ pollution (kg) emitted by production of 1kg of 25 common building materials

METAL SYNTHETIC CERAMIC NATURAL ORGANIC (BIOMASS)

Source: Wihan, J. (2007) Humidity in Straw Bale Walls and its Effect on the Decomposition of Straw*

In addition to using plant materials to build with, using materials with low embodied energy also reduces the building’s carbon footprint. The table below shows the embodied energy of all materials used in a typical strawbale house, and the percentage volume of these materials in relation to the whole.

This shows very clearly that almost 85 per cent of a typical strawbale house is made of materials with low embodied energy – in contrast to a masonry house, which uses roughly 85 per cent high-embodied-energy materials.

Embodied energy	Materials	Percentage volume of all materials
Extremely high	Plastic straps, lead flashing, hinges, locks, handles, nails and screws, galvanized downpipe	0.14%
Very high	Double glazing	0.09%
High	OSB, external plywood, Tyvek membrane	2.19%
Medium	Baler twine, floorboards, wooden gutters, cork underlay, celenit fibreboard, door/ window frames, lime plaster, hessian	7.34%
Low	Local timber	5.28%
Very low	Straw bales, sheepswool insulation, hazel, clay plaster, cedar shingles	84.95%

Source: Atkinson, C. (2008) Energy Assessment of a Straw Bale Building *

The way forward

The design of affordable houses is still under development, but amazonails is already building houses and other types of building with mainstream contractors at competitive prices. These prices will come down further as techniques are refined. Strawbale building in the UK has reached this point in only 15 years, with no government funding or financial backing from investors, which is a remarkable achievement and testament to its firm grounding in grassroots common sense, providing what ordinary people genuinely want. In this time, several unique individuals have built their own houses, keeping costs down by using their own and volunteer labour, running courses and reusing materials. Norita Clesham’s spiral house in Ireland cost her £70,000. Ben Law’s house in the woods cost him only £28,000. Rachel Shiamh’s house, which won the Grand Designs Eco-home of the Year in 2008, cost her £70,000.

The construction industry needs radical change if we are to bring the cost of homes back to a level that ordinary people feel they can afford without being in debt all their lives. This means a complete rethink of what we build houses from – going back to lessprocessed and local materials – and of the process of building itself – making it possible for people to participate in building their own homes in some way, as self-builders or through housing associations and partnerships with contractors. This is all possible!

Ben Law built his house of coppiced timber with infilled straw bales at a really low cost to a Grand Design.Photograph © Barbara Jones

* Carol Atkinson’s strawbale cabin is available for let, and you can find a copy of her thesis, Energy Assessment of a Straw Bale Building, on her website www.homegrownhome.co.uk. The cabin is pictured in the colour section of this book.

* MSc Architecture thesis written for the University of East London. Available at www.jakubwihan.com/pdf/thesis.pdf.

* MSc Architecture thesis written for the University of East London. Available at www.homegrownhome.co.uk.