New Skills in 2014: Build a Compost Toilet

We have a host of exciting short courses taking place at CAT in 2014, and up until the end of January there’s 10% off!  From the 4th to the 6th of July discover the power of poo during our ‘Build a Compost Toilet’ short course.

Although the vast majority of the UK’s houses are connected to the mains, there are some that must find alternatives to local sewage treatment works. Compost toilets can be efficient and practical, resulting in nutrient-rich soil to be used in the garden. They don’t use any water, although most types of toilet need a fair bit of room to allow composting to occur at a steady pace.

During this three day course the essentials for building your own compost toilet will be covered. With Grace Grabb, CAT’s water and natural resources specialist, course participants will learn about the changes human waste undergoes during the composting process. CAT’s resident carpenter Carwyn Jones will then demonstrate some of the techniques needed to build your own compost toilet.

Students sorting the nutrient rich compost
Grace sorting the nutrient rich compost

Composting your waste is a relatively easy and cheap way to reduce your waste and constructing your own toilet can be great fun. The soil produced after a year or two is pleasant to remove, and can be put straight on the garden (although preferably on non-food plants). Compost toilets are increasingly being built in allotments, back gardens and even indoors. Addition of the right amount of ‘soak’ gives good decomposition. A ‘soak’ is a source of carbon – typical materials include sawdust, straw and earth. The four main components to make your compost a nutrient-rich success are: heat, moisture, oxygen and a little dedication!

Carwyn constructing a timber frame compost toilet at Grand Designs Live in 2012.

From DIY to ‘off the shelf’ designs, this course can help you decide whether or not a composting toilet is right for you. The course invites anyone and everyone to join in, from urban gardeners to off-grid enthusiasts. Pupils will learn more about construction and cladding methods, as well as the biological processes that happen deep within the soil on a molecular level.

To discover a more holistic approach to waste management, sign up for the course now.

For those more interested in the theory behind compost toilets, rather than the construction methods, we offer a one day course: Introduction to Compost Toilets. This forms the first day of the Build a Compost Toilet course, and can be taken independently.

Remember, we are offering a 10% on courses booked before the end of January. For terms and conditions please visit our website.

Student Post: Planning for Real on the Prof Dip

We’ve asked some of our current students to write a short blog post about their studies after each module. You can see all of our student blogs here. Over the next year or so Rachel, a former long-term volunteer at CAT, will share her experiences on the Part II Architecture course.

In my last blog, I wrote about the beginning of our first project on the Professional Diploma: to create a vision for the future of the CAT site. We spent the September module forming our own impressions of the site and working on our ideas for how we felt the site could be developed.

Coming back in October for the next module, it was time to open the floor to the CAT community. In the lead up to the module, an invitation was sent out to CAT staff for a ‘Planning for Real’ exercise in the Straw Bale Theatre on the Friday afternoon of our module – a chance for us to meet the people who work at CAT and listen to their ideas. Arriving at the beginning of the week, this gave us a short deadline to get ready.

The centrepiece of the Planning for Real exercise was an enormous 1:200 scale model of the entire CAT site; a prop which would help in this discussion, and give us a chance to express our own ideas at the end of the project. In the weeks we were away from CAT, we had all worked individually on parts of the model (buildings, trees and the model base), but it became very clear at the beginning of the module that we still had a lot of work to do if we wanted the model finished by the end of the week!

Early days in the construction of the model

So we split up into groups and set about turning the bare bones of our model into something we could present to the CAT community. Some people worked on the buildings, modelling any that we had missed in our initial survey of the site, while others cut out the model base and used cork to recreate the dramatic landscape that surrounds CAT. A team was sent out to collect small bits of trees and twigs to represent the vegetation of the site, and add to the work that was being done to define some of the existing paths and areas of greenery that populate the area.

In between all of this, of course, we still had lectures to attend! This module the lectures focused on some aspects of building physics: heat transfer in buildings, thermal comfort and thermal mass being the main topics. The highlight of this month’s lectures, of course, was the sauna practical; a short stint in the sauna followed by a brief swim in the lake really helped to illustrate some of the basics of thermal comfort!

Adding the ‘greenery’

Finally, the week came to a close with the ‘Planning for Real’ exercise. We only just finished the model in time: even as people started arriving, we were still drilling holes for trees! Still, the afternoon was a success – we had a fantastic turnout, with an enthusiastic response to our questions about the future of the site. Everyone wanted their say, and we gathered a huge range of ideas and opinions during the afternoon from all the people who came.

Now it’s time to put those ideas down on paper…

The completed model

Student Blog: the first week on the Prof Dip

We’ve asked some of our current students to write a short blog post about their studies after each module. You can see all of our student blogs here. Over the next year or so Rachel, a former long-term volunteer at CAT, will share her experiences on the Part II Architecture course.

Last month I started the Professional Diploma in Architecture course at CAT. It’s a very different approach to the study of Architecture, one I’m really looking forward to!

The first week was an introduction to the realities of climate change, one that will really set the context for our studies over the next year and a half. To start the week, we were plunged in at deep end with Ranyl Rhydwen’s lecture on environmental change – an interesting summary of the science behind climate change and the urgent need for immediate action. Having worked with Ranyl for six months before the start of the course, I was already familiar with some of the topics he covered, but it was still daunting to see the scale of the challenge we face! His adaptation and transformation lecture later in the week gave us a slightly more optimistic look at the future.

Our other lecturers looked at different aspects of climate change and sustainability: Tom Barker introduced us to the importance of biodiversity and the need to protect and encourage it; Adam Tyler summarised the current energy situation – how much we use, and where it comes from. We also heard about CAT’s Zero Carbon Britain project from Tobi Kellner: a scenario where Britain could rapidly decarbonise and be run entirely on renewable energy. Finally, Tim Coleridge’s lecture near the end of the week talked about the role of the construction industry, and the need to adapt the built environment for future climate conditions.

The week wasn’t all lectures, however, as we also began our first studio project! We have been tasked with producing a master plan for the future of the CAT, a possible vision of what the site could be in the next five, ten or twenty years – working alongside members of the community here and building upon strategies that already exist.

Sketch by Kirsty Cassels

As most people were new to CAT, our first job was to get to know the site (or, in my case, get to know it better). So, sketchbooks and cameras in hand, we set out to explore. For two days we wandered the site collecting information, drawing and photographing the things that caught our eye, talking to members of staff and visitors and reading up on the history of the site. Even having already worked at CAT for some time, I was able to really get involved and learn new things about this fascinating place.

Later, as we collated our notes and sketches, the issues and problems we wanted to tackle quickly became apparent – as did the potential opportunities. We set about preparing some initial strategies and proposals (gaining some insight into designing by consensus along the way), and discussed how we were going to involve the CAT community in our project.

Next month, we will start the consultation with CAT members of staff and ask them what it is they want for the site in the future. We’ve done our groundwork – let’s see where it goes from there!

Timber frame and cob – getting muddy at Grand Designs Live

This weekend CAT is heading to Grand Designs Live in Birmingham! On Friday, Saturday and Sunday we’ll be building a beautiful timber frame structure and running hands-on sessions working with cob. It’s going to be an amazing weekend full of sustainable building and we’d love to see you there.

Grand Designs Live have very generously given us four pairs of free tickets to the show for CAT supporters. If you’re interested in coming on either the Friday, Saturday or Sunday of the show then email media[at]cat.org.uk with your name and a contact number and we’ll get back to you.

If you’ve ever wanted to try working with cob or learn how to strengthen a building for a green roof then this is the place for you. We’ll also show you how to make a pizza oven!

More information about the show can be found here. We’ll be updating our Facebook and Twitter feeds regularly throughout the show.

Planting the New Green Roof Display

A few months ago we posted an update on the new green roof at CAT, made possible thanks to a donation from the People’s Postcode Trust. So far the roof has been rather more slate-grey than green. Today, however, the planting of the roof began!

Jony and Riccardo planting sedums

We chose to colonise the roof with sedums – hardy alpine succulents – that are also known as stonecrops due to their ability to adapt to extreme growing mediums. Up at CAT we have sedums growing naturally in the disused quarry on slate waste.

The plants chosen for the roof, however, came from the walls and roof of Jony’s – CAT’s Artist in Residence – house. They are, he explains, “a completely homegrown tray of sedum from mid-Wales […] We’re pit planting these in organic potting compost. The roof is like a scree slope of shale that’s falling down the mountain. The plants root themselves in this medium, and the slate also acts like a mulch to stop weeds growing. You need something completely inert that weeds won’t grow in.”

Over the next few years these small plants will slowly grow and spread across the roof until they cover it entirely.

One of the species of sedum being planted

A Green Roof (or Living Roof) is like a shallow box garden. The bottom and sides are lined with a waterproof covering, then with a special membrane with small pockets to collect water to allow for slower drainage. A growing medium (in this case slate chipping) is laid down and then the sedums are planted.

Green Roofs are an important example of the kind of technology that can help us adapt to climate change. They help reduce surface water flooding in cities by absorbing storm water quickly, but releasing it slowly. They also help reduce hotspots of overheating in cities, provide important habitats for biodiversity in urban areas and offer potential spaces to be used for growing food. In general, they don’t give much in the way of insulation, so a roof still needs to be properly insulated.

Although Green Roofs are not a modern invention, it is the recent advances in water-proofing technologies that have led to Green Roofs becoming more widely used in sustainable construction over the last decade.

Preparing a sedum for planting

 

Compost Toilets: a Grand Design or a Space of Waste?

Last week CAT headed to London for Grand Designs Live. We had been asked to provide live demonstrations as part of the ‘Natural Building Methods’ section – an area CAT has some experience in! After much discussion, we decided on glue laminating demonstrations for making arches for a Timber Arc construction. The Timber Arc is a beautiful example of timber frame building, using local and low-carbon materials. It’s also a dual-chamber compost toilet.

CAT's stand at Grand Designs Live

Our goal at Grand Designs Live was twofold: provide the public with an interesting demonstration of glue laminating, whilst also raising awareness of different methods of dealing with human waste. Compost toilets are not for everybody, if you are connected to a local sewage system then chances are you will not need to deal with your own waste. However, some off-grid locations mean that people have to be a little more creative in the sewage solutions.

Glue laminating at Grand Designs Live

During our time at Grand Designs Live, one thing that kept cropping up again and again was bafflement. People often asked us why we were making a compost toilet, especially one so beautiful. Well, compost toilets can be efficient and practical, resulting in nutrient-rich soil to be used in the garden. They don’t use any water or chemicals, although most types of toilet need a fair bit of room to allow composting to occur at a steady pace. We have several composting toilets up at CAT, working alongside our reedbed sewage system and providing us with fertiliser for our gardens. Furthermore, why not make a beautiful building to house your compost toilet? It’s a place you visit each day after all! We also liked how the idea of it fitted in with the ‘grand design’ aspect of Grand Designs Live.

Work on the arches for the compost toilet

People certainly seemed to agree with us, judging by the level of interest we received each day. Engaging with people on environmental issues whilst also showing how we go about dealing with these problems was wonderful. Moving people’s thoughts away from bafflement and towards more environmental ways of thinking is key. Hopefully in the future CAT will be able to visit even more shows to keep spreading the word.

For more information on alternative sewage systems check out CAT’s information page on the subject. We also run short courses on sewage and waste water management. Further info here.

To see more of the Timber Arc, head to Jules’ website.