Are there any improvements to be made on the wall foundation to scale it down and make it easier to build DIY? What can we do to the wall foundation to make it easier for a small family to build it on their own?
CAN WE REDUCE FORMWORK:
Formwork is one of the big expenses of casting concrete. There is significant cost to it in both labor and materials. If we could stack functions on this part of the process, could we find more mutli-purpose solutions for formwork?
Use cmu as formwork – would help with defining the slab edge however this would result in your walls cracking when you get differential settlement. This is so since each cmu is a segment that is not tied to each other, and can sink in the ground on it’s own rate.
Use of bond beam cmu as formwork – better option than the plan cmu block since the cmu would function as a whole beam.
Using cmu to build a curb at the base of your stud walls – may be worthy to note that this can be useful if there are concerns for flooding. By itself they are not watertight, but they offer more potential than stud walls, with some more quality control and additives to it.
This is not about mass production construction methods. We can afford to explore techniques that do not scale to the construction industry. We are exploring options that might work on the family scale, a husband and wife team building their own home with limited manpower and resources. As with permaculture, we want to be efficient with our materials and we want long term benefits.
EFFICIENCY IN LABOR BY DESIGN
DIGGING WIDE IS EASIER THAN DIGGING DEEP – at least based on my experience. Obviously this will vary with the site soil conditions, but assuming you have cleared the land and are expanding a hole you have already made headway on-it is easier to grow the diameter of it incrementally than digging further down. I think this will make sense when providing details to a set of construction plans-to design the wall foundation to leverage what is easier to dig on site. I could essentially include 2 detail options, and an owner/builder could assess which is easier to implement on their property.
Opt for wider wall foundations than deeper trenches. will result in more concrete but will also be for easier labor. Cost of concrete at this level may be negligible. Need structural engineering analysis to compare the volume of concrete and added rebar, for both options.
Use of insulation to reduce formwork – might there be opportunity to use rigid insulation for formwork? Insulation at the wall foundation-along the perimeter of a home-helps to conserve the temperature of the house and benefits the wall and slab-as Bill Mollison himself discussed in one of his lectures. Can we use insulation as formwork as well when we cast this part of the slab and wall foundation?
Long term, need to explore providing insulated solution for wall footings. Homes in TX typically do not need insulation here. However, consider the recent freeze we had. Consider the possibility of the Maunder Minimum, as we have seen in history.
CONSIDER: add details in the construction drawings to show construction methods for efficient material use. Typically in my day job, construction methods are left to the general contractor. Again we are seeking options that can afford to be more scaled down. This is not about busting out a crew and mass producing a home. I envision a family setting out to build this type of home for themselves in phases as they are able to build-while going to a full time job and running a household.