In 2015 I began the task of building a three bedroom cabin for myself and my family, with limited building experience and a small budget. The experience has changed my life and has gifted me with new skills, new perspective and some useful tips for anyone wishing to attempt something similar.
The aim of the project was to build an off grid, low impact, energy efficient dwelling with minimal waste. With further requirements that no heavy machinery may be used, no permanent foundations be laid, and that the dwelling must be designed and constructed as a temporary structure i.e. with its future disassembly in mind for a future One Planet Development project.
The building method was developed by Marc Hayler over a 30 year career of designing and building experience. Marc has honed the process down to simple stages and this meant that I could build the cabin in logical steps over a year.
Building the Frame
The design and consultation process began in January and site clearance began in February.
In March, 18 foundation pads were poured to make a footing for stacks of 6” blocks to level the site, drainage trenches were dug, and back-filled with perforated piping and builders rubble scavenged from skips and the local recycle centre.
The groundwork was completed by mid April and the (6x2”) timber base frame was laid down to accommodate the 2x2” twin stud walls, these were topped with a 6x2 wall plate onto which 6x2 rafters were laid.
As spring arrived in May, 8mm Oriented Strand Board (OSB) was attached to the outside of the framework and the window apertures were cut out using a chainsaw with old polytunnel plastic stapled to the holes to keep the rain out.
As the dry weather became predictable in June, the work went from part time to full time, the internal ceiling framework (perlins) was attached, with Expanded Polystyrene (EXP) sheets squeezed between them, this provided a solid enough platform to roll out the 6” fibre glass insulation, creating an 8” insulated roof, this was covered with a breathable, water resistant material, held down with 2x1/2” counter baton, to this was added a 2x1” roof baton and the roofing tin bolted on, to complete the roof.
In July the flooring was laid, 9mm OSB ceiling installed and the walls infilled with the Earth wool insulation. A good friend Dan Pope devised an excellent hot wire cutter to trim sheets of EXP into 2x2” batons, these were squeezed between the 2x2 studs and a screw driven through to form a strong and insulated 6x2 upright, that would provide a fixing point for the 9mm OSB wall covering and bear the weight of the framework for the sleeping loft and the ceiling. Soffits, fascias and guttering were all installed at this stage which allowed the rainwater collected from the 66sq.m roof to be directed away from the building.
August saw the installation of the wiring for lighting and mains, also the completion of the flooring and subsequent partitioning for the compost loo, kitchen bathroom and sleeping loft spaces.
In September the windows were installed and the breather membrane (frame shield) was stapled and 2x12” counter baton added to create an air gap and provide a fixing point for the cladding.
Inside, we chose to limewash the OSB, filling seams with decorators caulk and adding colour with clay paint.
October was a month of frantic plumbing and finishing as we had a strict deadline to meet by the end of the month. An impossible succession of day and night shifts saw internal doors hung, kitchen units installed, compost toilet built and temporary ladders put in to access the sleeping lofts.
We moved in on the first of November on a bright, warm day, with cladding to install, a porch and deck still to build and many small problems still to be resolved.
It rained relentlessly for four months after that, but the work had to continue...
Most of the essential work on the cabin was completed by December, we had managed to build a dry warm, efficient, off grid dwelling for under £20,000 in material costs.
The porch and decking were completed in spring 2016.
A total of five black bin bags made it to landfill while all other off-cuts and waste were carefully separated and recycled, all waste wood was processed as firewood to feed the woodburning stove.
This project has given me a new appreciation for the work of master builders and the importance of detail within the building process, it gave me confidence and skills to design and build full-time and to encourage others to do the same.
The Cabin could not have been built without the contributions from: Marc Hayler, Dan Pope, Donald Adams, James Armstrong, Jason Brown, Craig ,Melanie and Mandla, Tomosso and Naiomi, Emma Steele Morgan, Rob, Angie, Roman and Jana, Steve Douglas, Rob and Mapes, Foenix Freshwater, David and Jinzy Robinson, Erika and Adam, Neil and John.
Matthew Douglas lives and works in Carmarthenshire, Wales and continues to design, build and find elegant solutions in an increasingly confused and challenging world.
The cabin has now been dismantled, and Matthew and his family are looking for a potential buyer for the building, which is now in kit form.
If careful measures are taken, all polystyrene ‘dust’ can be gathered and bagged and stuffed into the floor or wall cavities, this will still provide insulation, and saves it from becoming landfill.
Reclaiming your windows may appear to be a money saver, however the compromise on shape and placement of windows are probably not worth the extra effort, it is just as fiddly and time consuming to adapt your building design and apertures to accommodate old windows as it is to order the size of double glazed unit you require and build a casement and frame to fit it. Also you can design and make the windows to fit easily and quickly between the stud work of the building, thereby saving further time and effort.
I found that the purchasing of a twin wall pipe a great advantage, since all my materials needed to be sent down a steep bank, I could safely slide most of my timber down the pipe, rather than carry them all down.
Roof tin can be bought in long lengths, the mono pitch roof required 6m lengths and these were unwieldy at best, I would recommend buying two 3.2m lengths and overlap them, as I have scars to show awkward they are to move, especially up or down any incline.
If possible, design deep eaves all round to provide a rain shadow, this will protect the cladding and windows from deterioration. I had an 80cm depth along both lengths and a 30cm depth on either end and would now extend each even further. Especially given the rainfall in the west of the UK and Ireland.
Make sure you have a flexible ‘move in’ date, as doing any work on the cabin once we moved in seemed to be ten times harder and slower. Complete it all before you move in.
The materials and cabin dimensions
4.2m to the ‘apex’ of the roof
4m wide (plus 160cm eaves)
Foundations: 18 x 50cm square poured concrete slabs and 6” solid dry stacked concrete blocks
Walls: 6” deep Twin stud walling (2x2 with 2x2 polystyrene infill)
Insulation: 6” Earthwool and 2” Expanded Polystyrene sheets (plus some reclaimed 4” and 2”
Roof: corrugated tin
Windows and doors: a mixture of re-cased and re-framed double glazing units and reclaimed and restored window units and doors
Exterior cladding: 6” Douglas fir feather edge
Flooring: 18mm strand board (with vinyl) and reclaimed scaffold boards
House heating and water heating: Morso Squirrel wood burning stove
240v electricity: 1kW solar array with x2 12V calcium batteries, 24V inverter
12V lighting: 150W solar panel with x1 12V leisure battery, LED lights throughout
Interior cladding: 9mm Strand Board
Porch roof: transparent corrugated PVC
Porch uprights: round wood poles
Porch and decking frame: 4” and 2” treated timber
Decking: reclaimed scaffold boards