Category Archives: Castle Hill School

Castle Hill School

 

External cladding: Larch and lime

10 Oct 14
Michelle Gaffaney
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Now the straw walls of our eco-classroom at Castle Hill School have had their first coat of lime render, it’s time for the cladding.

We’re using Scottish-grown larch boards – a durable hardwood which will naturally mature over time to an attractive silvery grey.

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A ‘truth window’, created so that users of and visitors to the building can see the material behind the cladding.

Other parts of the building have been simply rendered using traditional lime, a material often used on straw buildings. Lime is a carbon neutral building material, created by burning limestone. When lime is applied to any surface, the carbon dioxide released during the burning process is re-absorbed as the render dries.

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Cosy cob reading nooks

09 Oct 14
Michelle Gaffaney
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One lovely feature of our straw bale eco classroom is the creation of two cosy reading nooks.

They’re made from cob, a mixture of clay, straw and aggregate (more on cob here) and are specially designed so that children can curl up inside with a good book.

They’re not yet finished, but these photos show the raw state – a simple wooden platform and cob casing.

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Arthur, our plasterer, tries it out for size.

Straw bale classroom: Lime render and clay plaster

02 Sep 14
Michelle Gaffaney
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Our straw bale classroom at Castle Hill School is really starting to take shape now!

The walls are up, the roof is on, and it’s time to start covering the walls.

The naked straw walls, before rendering.

Externally, we’re using a lime render to protect the building from the elements.

Lime is often used on straw bale and cob buildings and is a traditional building material. It is particularly suited to our harsh Yorkshire weather, as it has a sponge-lique quality, absorbing rainwater in bad weather, then releasing it, rather than allowing it to soak into the inner wall.

Here’s Arthur, our plasterer, tackling the first coat:

Lime render

Arthur lime rendering

The difference is astounding, and it’s so exciting seeing the classroom start to look more like a ‘real building’!

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Internally, we’re using clay – the oldest and simplest building material of all.

Clay is applied to the wall much like regular plaster, except that more coats will be needed. We start with layers of rough clay plaster, mixed with coarse sand to grip tight to the straw walls. Once this has built up, we apply a final layer of fine clay plaster (made using a finer sand) to give a nice smooth finish.

clay plaster

 

INNO-THERM / Metisse recycled denim insulation

01 Sep 14
Michelle Gaffaney
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Our straw bale classroom has all kinds of eco-friendly features on top of the straw itself, from non-toxic clay plaster surfaces to low-impact cob reading nooks.

Another way we’re reducing the classroom’s impact on the environment is through the floor and ceiling insulation:

INNO-THERM

INNO-THERM/Metisse is a unique insulation material which is made from recycled denim and cotton.

It can be used just like regular building insulation, but has a number of features which make it a much better choice for our eco-classroom:

  • It’s non-toxic, ensuring a safer environment for children and others using the classroom.
  • It’s non-itch and chemical-free – much safer for builders working on-site who will be handling the insulation.
  • It’s made from 80% recycled waste, reducing landfill
  • …and it can be recycled again after use if needed!
  • On top of this, it takes 70% less energy than regular insulation to manufacture.
  • It has an excellent U-value of 0.19 – this means that its insulative properties far exceed building regulation requirements, so it will keep the classroom warm in winter and cool in summer, in turn reducing energy bills for the school.

Find out more about INNO-THERM/Metisse on the website: inno-therm.com

INNO-THERM in the classroom floor

INNO-THERM in the roof

Adding a green roof to the straw bale classroom

28 Aug 14
Michelle Gaffaney
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The walls are up, and it’s time to add the green roof to our straw bale classroom at Castle Hill School.

First the beams go on

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Then we need to edge the roof

It will be a green roof – a living ‘lawn’ of sedum on top of the classroom, so a strong ‘fence’ around the edges is needed to prevent the ground from shifting when it rains. There is also a pathway of gravel around the lawn to provide structure and drainage:

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Adding the sedum

For a project of this scale, it’s easier to buy sedum and soil in rolls, like this:

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They can be easily unrolled onto the surface of the roof:

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Dan thought he was at the park and tried to take a nap...

Once complete, the roof looks like a field – it’s hard to tell it apart from the landscape behind!

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VIDEO: The classroom so far

11 Aug 14
Michelle Gaffaney
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Take a look at our straw bale classroom in progress!

Our wonderful work experience student Autumn has put together this fab video showing the build so far at Castle Hill School. It shows the foundations being dug and built, the straw bale walls going up, and finally the timber roof going on:

Of course, there’s still plenty to do. Watch this space for further updates as we continue work on the new eco-classroom at Castle Hill School.