Straw Bale Building

One of the main purposes of this blog will be to track the progress of my garden development. The mission of this is to build a small (5mx4m) building at the back of my garden which will give me an area to play my drums and music without disturbing the neighbours. I’ve always been interested in developing solid buildings with a small environmental footprint as possible, and I am treating this project as an ideal opportunity to practice these skills.

The work is taking place at the back of my garden, and the plan is to develop the building foundations and stem walls from used car tyres rammed with earth. The wall will be built from straw bale, and this will be used as an infill on a timber frame supporting a living roof. Some plans of the foundations and final look of the building are below.

There are many fantastically detailed projects on the internet which have helped develop my ideas for this project, and they have inspired me to write and maintain this blog to help add to the growing number of resources which document building with an environmentally friendly approach. I expectedly hear “three little pigs” jokes when saying my building will be built from straw but the reality is a building which will last and will be cheaper and warmer to build than a brick and concrete equivalent.

Project Costs

I’ll try and track the costs of the project here, to get an estimate of how much this kind of thing costs overall. I’m not even going to attempt to think about the amount of time I’ve put into it though!!

Straw Bale Wall
Straw bales – £4.50 each, 100 in total, £450. (yes, they are quite expensive, I had the unfortunate timing of buying at the end of a particularly bad summer!)
Lime Plaster – £432 – Ty Mawr Straw Bale Lime Mortar Mix (80x25kg bags)
Lime Wash – £60 – Ty Mawr (2x20l tubs)

Retaining Tyre Wall
Wall plate Timber – £24 – 10 lengths of 2.4m 2″x4″ rot resistant treated timber

Base Tyre Wall & Foundations
100mm Drainage pipe (non perforated, straight, 6m) – £21.60 Used underneath the building to drain from the front to the back up to the front tyre wall
Heavy Duty PVC (14m x 2m) – £88.74 Used as waterproofing behind the tyre wall across the whole garden, not just the building
Heavy Duty PVC (10m x 3m) – £70.20 Used to line behind the tyres on the retaining wall at the building
Terram Groundsure 900 (2.25m x 50m) – £60.40 Used to assist drainage behind the retaining walls and also on the green roof as protection for the roof liner
Delivery of above two items – £10.80
80mm drainage pipe – £30.00 (perforated, flexible, 25m) Used as a french drain around the building boundary
“T” Pipe junction – £12.00 1Used to join the perforated pipe at the back with the solid drainage pipe
Y Pipe junction (x2) – £20.00 Joining the perforated pipe at the front with the solid drainage
Straight pipe joins (x2) – £8.00 Allows the junctions to join with the main pipe and extend the main pipe in places. 

Green Roof
0.85mm Greenseal EDPM Rubber (6.5m x 7.5m) – £315.91 For the roof waterproofing

Total of project so far – £1546.98
(This is not including the costs of the wood forming the steps below the building, but it came to roughly £80 if you are interested.)

Some useful links I have found browsing are listed below, along with some useful books I have read in the lead up to this project.

Blogs on Eco-Building Project

Books on Environmental Building
Building with Straw Bales
Building Green
Small Green Roofs 

Eco Groups (who helped promote this project blog)

Relevant Posts from this Website
Earth rammed tyres experience

I am also looking to build a mailing list for people who are interested in volunteering for the project – I anticipate that I will have plenty of work available in 2012 and 2013 for all aspects of the project, from creating earth rammed tyres for the foundations to plastering the walls when the straw bale is in place. If you are interested, please add yourself to the newsletter on my volunteering page.