Tag: straw panel

  • HPH333 : What is the One Planet Development scheme? – with Brendan and Ludka Powell

    HPH333 : What is the One Planet Development scheme? – with Brendan and Ludka Powell

    Ludka and Brendan Powell explain the Welsh ‘One Planet Development’ scheme and how it led them to building an off-grid, straw panel Passivhaus.

    Interview with Ludka and Brendan Powell

    Ludka and Brendan Powell are self-builders with an interest in sustainability. They began to question whether the way they were living was the best way to live, and could they find an alternative way that connected them with their surroundings more.

    One Planet Developments (OPDs) are a Welsh Government initiative

    By granting planning permission to build on agricultural land, the scheme aims to get people back to living and working in the countryside, growing food locally. A One Planet Development means living a sustainable lifestyle, with the lowest carbon footprint you can manage, producing your own power and dealing with your own waste.

    A key goal is to ultimately produce 60% of your own food on site, as part of meeting your ‘basic needs’ within five years. Basic needs include council tax, running a car, phone bills, and the food that can’t be produced on site.

    Meeting the five-year goal of an OPD requires a business plan

    It’s very difficult to quantify how you’ll be doing after five years, so the scheme requires that you have a business plan and produce an annual progress report. At the end of five years, if you haven’t quite reached your targets but are on the right track then you produce a second business plan to show what will happen next to reach the goal.

    At the halfway stage of their own five-year timeframe, Ludka and Brendan have found it to be a big ask but they are on schedule. Anything they overproduce helps with their income. For example, they sell salad to local shops and make sauerkraut from cabbages, alongside producing honey.

    One planet thinking is long-term, holistic thinking

    An important part of the OPD is that Ludka and Brendan are trying to regenerate the land by transitioning from monoculture. They are trying to bring biodiversity, grow crops alongside keeping animals, and farm organically.

    They have planted an orchard and an extra acre of woodland to attract wildlife, and keep bees to help with pollination. It’s about working with nature rather than being geared towards profit, and the real benefits might not be seen for a decade. It is about attaching other values than just a monetary value to things.

    The one planet way of life is sustainable

    Doing everything in five years is a massive challenge, and Ludka and Brendan acknowledge they might not be doing everything right straight away. However, they are confident that after ten years everything will be perfectly fine.

    It is sustainable in the way they are putting a lot of energy into the land, but getting so much back from it in terms of fulfillment. As well as seeing the productivity of the land improve, they are also seeing change in terms of people being willing to go out of their way to buy produce from them rather than from the supermarket.

    OPDs attract determined people

    Building a house is often the biggest thing anybody undertakes in their life, so doing that alongside regenerating a piece of land and building a sustainable business has been intense for Ludka and Brendan. Taking on a self build is not the only route for those undertaking OPDs and some opt to build tiny houses using the Caravan Act. However, for Brendan and Ludka it was an opportunity to create more space for family life and have a hardy kitchen for processing their crops.

    People who do OPDs tend to really care about the planet’s future, and recognise that we can’t carry on living as we are. There has to be different way.

    One Planet Development Policy can evolve

    OPDs are an experiment to try and take society in a better direction. There are not many of them, but the existing developments have been successful in feeding people locally and improving the ecology of the land.

    Not everything in the scheme is perfect but it gets reviewed and recommendations for improvements have been made.

    Being off-grid is not mandatory for OPDs

    Ludka and Brendan have no utilities coming to site. Their water comes from a borehole, and electricity is generated from solar PV. Waste is dealt with through a composting toilet and reedbed system.

    Anyone creating an OPD can choose the most sustainable solutions to suit their site. Using mains water is not really a problem, but one of the principles of the initiative is dealing with your own waste.

    Off-grid living is more mindful

    The project is labour intensive, even more so because Ludka and Brendan also have three children. But it also makes them more self-reliant and aware of their actions. They can’t just switch on the electric oven at nine o’clock at night in December because they want to heat something up.

    Their children are growing up with the same values. For example, if they have a bag of sweets, that creates plastic waste. What will happen with the waste? They don’t have a throwaway culture.

    That extends to the household waste and their sophisticated composting system. In a ‘normal’ house it’s really easy to just flush the toilet and not think about where the waste is going. Ludka and Brendan have to constantly think about what they’re doing with their waste and keep an eye on everything.

    A Passivhaus was the natural choice – in more ways than one

    Having lived in a cold and damp house that was never truly comfortable, Ludka and Brendan knew they wanted a house that was going to cost very little to run and not need lots of heating.

    Making it as well-insulated as possible meant they wouldn’t be spending time on the land sourcing firewood to burn. In their temporary accommodation they were burning wood all day and half of the night in winter; now they only need enough to make dinner on the cooker, with enough residual heat to heat water.

    One Planet living means using sustainable and natural materials where possible, and minimising your carbon footprint – so a timber-framed Passivhaus with straw bale insulation minimised both operational energy and embodied emissions.

    The straw bale system performs as promised

    Getting a straw bale house to Passivhaus standard is difficult, but the EcoCocon system has delivered what was promised. The addition of wood fibre insulation around the outside brings the insulation up to the required level. Once the system was in place, it was simply a matter of following all of the normal Passivhaus principles to achieve the necessary airtightness and so on.

    The wraparound veranda helps the house stay cool in summer

    A veranda provides shading that is at just the right angle to maximise passive heating year-round without summer overheating. The veranda is also somewhere to live outside in the Welsh climate.

    In the summer, the windows never need to be opened because Ludka and Brendan never feel they need to do so. And in autumn, they were amazed at how warm the house continued to be when the air temperature outside started to cool.

    During winter, the sun shines through the windows and warms the polished concrete floor, which helps to keep the house warm until the following day. And the floor was a practical choice too, because it’s easier to sweep when bringing in mud from the fields.

    Making careful material choices throughout

    Yet another advantage of the concrete floor is that Ludka and Brendan didn’t have to buy carpets or wood flooring.

    Keeping within the One Planet principles, they have used recycled materials wherever possible – including recycled foam glass in the floor, and cellulose (recycled newspaper) in the roof. Sourcing local materials was also important. All of the cladding was made within ten miles of the site, and all of the architraves are made of local ash.

    Inside, they’ve used a kitchen recycled from another house, and done similar with bathroom and utility room fittings – all of which helps to save money too.

    MVHR can work in off-grid houses

    Ludka and Brendan’s MVHR system uses very little power, around 20 to 30 Watts all the time. On a few days in December and January, when there’s little light, they’ll only run the MVHR in the day. There’s been no detrimental effect from that.

    They run two inverters, having fitted a smaller one that can cope with demand from the MVHR, lights and laptops. The larger inverter is still needed for appliances, but it was using over two kilowatt hours per day by itself. Using the smaller inverter means they can now more easily survive the winter without getting short on power.

    Running businesses together helped with teamwork

    Both Ludka and Brendan were very engaged with the project, rather than one of them leading. Both have been involved right from the ground up, but they would feel strongly about different things. The important thing was to ask each other’s opinion.

    Through running businesses together they have learned to delegate, so Ludka wouldn’t deal with carpentry but did do a lot of wet processes like clay plastering. Plasterboarding and decorating ceilings were two jobs in particular that provided to be long and laborious!

    Creating a One Planet Development requires strong-mindedness

    You have to be resourceful and dedicated. Never underestimate how much there is to do, but never give up. There is a solution to everything, and Ludka and Brendan have found they’ve become really good at researching and solving problems.

    Projects don’t go the way you want them to, and you have to continuously pick yourself up from failure, but somehow it all makes sense in the end. Creating an OPD has brought a sense of integrity to Ludka and Brendan’s life, as well as a sense of community from within the One Planet movement itself.

    Find out more

    Huff and Puff Construction

    Hawkland Construction

    EcoCocon

    One Planet Developments

    One Planet Council

    Transcript

    Get more in The Hub. Juraj Mikurcik explains how you build with the EcoCocon straw panel system

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  • HPH310 : Important takeaways from an exemplar straw panel Passivhaus

    HPH310 : Important takeaways from an exemplar straw panel Passivhaus

    Juraj Mikurcik, Nick Grant and Mike Whitfield reflect on the award-winning Old Holloway project, which is built with EcoCocon straw panels and is a certified Passivhaus.

    This podcast is slightly different to normal because it’s been compiled from video footage. The video, which can be seen above, is a 10-minute overview of Old Holloway (or you can watch a 2-minute version here).

    Passivhaus specialist Nick Grant and Passivhaus builder Mike Whitfield have both been on the podcast before. Architect Juraj Mikurcik has been a friend of House Planning Help over the years and we were delighted to see his home win at the UK Passivhaus Awards and highly commended at the ASBP Awards.

    This podcast explores what makes this house build so special.

    The design decisions are easy to read and appreciate

    In an era of climate emergency we should all be thinking about limiting our environmental impact and reducing our energy consumption.

    Old Holloway (with a floor area of 95m2) was built to a tight £150k budget and achieves so much. Not only is it a highly efficient home, but it’s been built with as many plant-based and non processed materials as possible.

    Constraints impacted the form of the house

    The project faced tough planning challenges to get a building consent, needing design approval from the Duchy of Cornwall estate (who sold Juraj the land) before even submitting an application to the local authority. These constraints led to a single storey building and perhaps the rural aesthetic.

    The architectural design of the building

    Nick Grant says it’s his favourite house for all sorts of reasons. Mike Whitfield feels the atmosphere in it or soul quality is really good.

    Sufficiency and affordability informed the scale

    When it comes to scale it’s about finding the right balance. If you build too big you have redundant space whereas if you build too small then people struggle to go about living their everyday lives.

    Juraj compares Old Holloway to the TARDIS, because it looks small from the outside but feels big from the inside. An open cathedral ceiling helps create a great sense of space.

    Old Holloway’s floor plan

    Nick also believes small buildings have an advantage.

    “Small buildings can look interesting because the texture and contrast of the materials is enough. When buildings become very big that’s not enough. So however characterful the render is or the brick, it still looks big and bland, so you then start articulating the building and adding bits on because you think it looks plain.”

    Re-evaluating how much space you need is a smart move… but it’s also important to build what you can afford.

    Materials matter when building a Passivhaus

    If you care about the environment then reducing the embodied energy of the building is essential.

    Mike says that some people believe it’s either natural materials or energy efficiency.

    “You can construct an argument to say that the embodied energy in a Passivhaus isn’t that important because you’re going to save so much energy over the life of the house.”

    This might for example lead you to build with insulated concrete formwork.

    Juraj specified a Passivhaus certified straw panel system.

    Mike continues.

    “Ecococon gives you a really instant, pre-fabricated system that is genuinely low energy.”

    The structural concrete slab is also the finished floor

    At the base of the house a concrete slab has been used, but this structural slab doubles as the finished floor. It took Juraj an incredible 90 hours to polish it!

    An insulated raft is made using the ISOQUICK system
    The concrete pour
    Juraj spent 90 hours grinding down the slab and polishing it
    The structural slab is also the finished floor

    This route is cost effective. The only downside is that it’s tricky to guarantee a certain finish.

    The straw panels are wrapped with an airtightness membrane

    Nick’s house was built with straw bales and he often dissuades people from bale building because it’s hard to get them to perform well.

    Juraj stresses that EcoCocon is a timber panel based system, produced in a workshop, that uses compressed straw as the infill insulation. As such it’s even a Passivhaus certified component.

    To achieve Passivhaus airtightness requirements the building is wrapped with a membrane on the outside. Nick explains that generally having the airtightness layer on the outside is something they try to avoid. Juraj has been careful to specify the right product in order to avoid condensation issues. The membrane has vapour openess and the whole build was modelled in WUFI.

    An airtightness membrane with high vapour openness wraps the house externally
    Warmcel is pumped into the roof void
    Studwork goes up internally
    No paints are used internally; the clay plaster is the final finish

    Don’t be afraid to experiment and seek advice from others

    Old Holloway is clad in charred timber. This is something Juraj had been wanting to experiment with for some time. He loves the finished effect it created, even if the process was time-consuming.

    Charring the cedar
    The finished cedar cladding

    Juraj believes the crinkly tin roof is the biggest bargain of the whole project. He calls it a ‘very Australian detail’.

    Nick says that it’s good to see it used simply.

    Woodburners/stoves are not a great fit for Passivhaus

    One thing Juraj would do differently is not include a woodburner. Although it can be incorporated in a Passivhaus (and has been here) there are lots of reasons to deter you.

    • There are better ways of providing the background heat.
    • It’s old-fashioned thinking (burning anything releases a lot of particulate which is not good for health). People like Passivhaus because of the indoor air quality but having a logburner – no matter how sealed the system is – does release particulate into the room (which appears on the MVHR filters)
    • It is a faff to clean up
    • It takes up space
    • You have to keep children away from it
    • Even though it’s sized correctly, it is not the same experience as a roaring open fire in an in-efficient house. Nick comments that on social occasions the fire is always out before he arrives because the house is already warm enough!

    Nick, Mike and Juraj all have fires, but now say they wouldn’t do it again.

    Mike suggests that if somebody is fixated on having a fire, then go for a bioethanol burner. This can give the effect of a fire but doesn’t need lots of kit. And if you decide it’s a waste of space you can just get rid of it!

    Juraj erects a sail for additional shading in extreme heat

    Total control over solar gains in summer is a masterstroke

    Sensible glazing ratios, a significant roof overhang and a pop-up awning make Juraj’s house one which will not overheat.

    The Passivhaus process is always looking for the best form factor. Old Holloway is not an exact rectangle because it dips in on one edge. This hasn’t been done because the shape looked boring and it needed to be articulated: this provides complete solar shading of the biggest windows in summer and a nice area to sit outside whatever the weather.

    Nick comments:

    “You go from a box it’s more expensive, so then you’ve got to say is it giving me some value for money, and here I think it really does.”

    Find out more

    Visit the website of Old Holloway

    Visit the website of Mike Whitfield Construction

    Visit Nick’s website for Elemental Solutions

    Follow Juraj Mikurcik on Twitter

    Follow on Nick Grant on Twitter

    Download a PDF transcript of this episode

    Please connect with us

    Subscribe, rate and review us on Apple Podcasts

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  • Achieving Passivhaus Standard with Natural Materials – Bjørn Kierulf from Createrra

    Achieving Passivhaus Standard with Natural Materials – Bjørn Kierulf from Createrra

    Is a straw bale construction really a good way to reach the Passivhaus standard?

    And would a straw bale Passivhaus be robust over time?

    In this article I speak to Bjørn Kierulf from Createrra about achieving Passivhaus standard with Ecococon straw panels.

    Bjorn-Kierulf-photo

    Bjørn Kierulf was originally an industrial designer and won a number of national awards for his work between 1993-2001. He lives in Slovakia with his wife, who is an architect. Since 2007 their firm Createrra has focussed on Passivhaus and they have now completed 50 buildings that meet the standard.

    They also have developed a reputation for achieving the Passivhaus standard using natural materials and have recently completed their fourth Passivhaus using Ecococon load-bearing straw panels.

    Interview with Bjørn Kierulf

    1. What is the difference between building with straw bales and building with straw panels?

    The main advantages are quality and ease of execution. Anybody who has been on a traditional straw bale building site knows that the same problems arise every time: different sizes and densities of straw bales, protection of the straw from moisture during storage or building and lots of details that are not always solved properly. The work is very labour intensive and is often done in workshops. Professional builders are aware of the risks involved and have problems pre-calculating the amount of work needed. Usually the only suitable period for building is after collecting the straw from the fields and before the winter sets in.

    Straw panels Ecococon can be pre-produced at any time of the year and assembled in just a few days on the building site. The panels are immediately covered with a membrane providing airtightness and protection against rain. The precision of the panels are 1-2mm and the straw fills even the smallest gap at 110kg/m3. Each panel is pressed with a force of 5 tonnes. The surface of the straw is completely flat and can be covered with clay plaster.

    Going from straw bales to straw panels makes it possible for any builder with experience in wood to assemble a quality house built from straw in record time at predefined costs.

    Bale-panel-structure

    Lintel assembly

    2. How does the process work?

    Usually any house plan can easily be turned into a 3d panel model. Because of modularity, there are nearly no constraints and the architect is free to produce what he thinks is best. After a panel plan is produced, also the exact costs can be determined. Production of the panel is started after the buyer and the architect have signed the panel plan. Usually a few weeks later the panels are delivered on site ready to be assembled. Assembly of 100 m2 or more of wall is possible in one day with a skilled 4-man team.

    3. What determines the size of these panels?

    All panels are 400 mm thick. There is a standard panel of 120 cm width x 300 cm height, but smaller panels are custom made to suit the design. The minimum width or height of the panel is 400 mm. To complete the modularity, there are panels with an inclined top (0-45°), braced panels, sills and lintels to be installed above the windows. Special elements are in development for integrating shadow devices in the openings.

    4. Are there any limitations as a designer by using these panels?

    You need to take into account structural concerns (above 2 floors the structural design should be carefully thought through in advance). It helps if the designer has an understanding of the modularity and types of panels, especially for cost optimising the design. The designer should also understand the concept of airtightness we apply and design accordingly connections to other building elements.

    5. What is needed on site to put these panels together?

    The panels can be heavy (50kg/m2) but can be moved on rollers or by tilting over the corner to the necessary place. For unloading from the lorry and building the second floor a crane is usually needed. Other than that a good screw driver and screws are all you need. Special clamps can be obtained by the producer to pull the panels together before adding the screw.

    Panels-screwed-in

    Screwing the panels together

    6. How are these panels rendered? And is the render the airtight layer?

    The cut straw surface is an ideal surface for clay render. Over the wooden construction 5 mm thin wood-fibre boards are tacked on for the clay plaster to stick better. There is no special preparation necessary before rendering. We did our first two houses with an airtight clay render inside, but this was cumbersome and resulted in a lot of work. The result was very good in the end, but we used a much simpler method on the next houses we built. We now add a membrane on the outside of the straw, between the straw and the wood-fibre board. It is very important that the membrane has an Sd<0,2m, in effect the construction is open for vapour to cross all layers, but any air-draught is minimised. It is usually air movement that transports most moisture into the construction, and then causes damages from condensation. We have achieved airtightness as low as n50=0,14 1/h and have calculated this construction with WUFI to be sure that there is no moisture build up over time.

    Rendered-wall-of-bale-panels

    Clay plaster and rounded edges at the window connection

    7. How does building with panels affect the speed of construction?

    As one builder said: “Everything took longer than we thought, except the assembly of the panels.” Of course the time saved on the building site is spent in the factory producing the panels, but overall the advantages are huge. With the airtightness concept and the wood-fibre board on the outside we have developed a system that is in general very effective to build.

    8. How cost effective is this construction method?

    The higher the cost of labour, the more cost effective the solution is. Production is already partly mechanised and can be made even more effective in future. The truth is, that building with natural materials does cost more than with widely available materials. A major part of the price difference comes from lower turnovers and necessary higher margins. Even if today a straw panel house with clay plaster probably costs a bit more than a traditional house, it does not have to be so if the system gets adopted widely.

    9. What’s the biggest challenge of building this way?

    Tradition. In the building industry it takes sometimes generations to change perspectives. Traditional approaches, ridgid regulations and ignorance need to be overcome. Technically there are no obstacles, only a huge potential to develop the system further.

    straw-bale-panel-house

    Passivhaus across the border in Austria built with straw panels

    10. Do you think that Passivhauses built with natural materials can ever be a large part of the market?

    If we want to take the last IPCC report seriously, I think aiming at anything less would just be irresponsible. Passivhaus has proven its place effectively over the last twenty years. But after managing global warming, humankind will still be faced with an even larger challenge: limited resources and the necessity of proper materials management. The only solution I can see longterm is the implementation of Cradle to Cradle concept across the building industry. With the massive amounts of materials involved, major use of natural materials will be inevitable. This does not exclude the development of new materials based on renewable sources.

    11. Have you achieved Passivhaus standard with buildings constructed of other natural materials?

    Our first Passivhaus was built as a light wood frame construction with blown in cellulose and 30 t of clay bricks and plaster. We have since then moved to massive wood construction with elements from the German producer Lignotrend, creating exclusive interiors with wooden acoustic ceilings and clay plaster. The inclusion of straw is a natural step in the right direction — straw, wood and clay, all renewable materials available in abundance can be turned into beautiful Passivhaus buildings and I sincerely hope many other architects will follow in our footsteps.

    Timber-cladding-over-bale-panels

    Passivhaus in northern Slovakia built with straw panels