House Design & Construction
Last Updated: July 9, 2018

Most recent images first (read upwards);
plan drawings, text and additional references at bottom...
 

And the filled result (wine corks were used to plug the holes once the void was filled).

 

The manual grout pump setup for the fill

 

Another area we had problems with, when we did the earlier (hand application) concrete trials, was the use of fine mesh on both sides of the construct. We realized that we couldn't get concrete through the fine (lath) mesh and ended up removing one side's mesh, but not before we had a region concreted. This region was interesting in its notable strength (even though the concrete on each side was only ~1/2"), but I wanted the internal void filled so the interior steel didn't corrode over time. Here you see the holes drilled so we can fill it with grout using an Airplaco manual grout pump.

 

Here you see a void around the rebar that we are chipping out. This resulted from the slump and is something to watch for regardless of how concrete is applied.

 

Part of the problem with hand application of concrete is what I came to call the 'playdough effect'. Basically, pushing concrete into the mesh (at the low slump required) causes a separation where it passes through the mesh. Lower down, the concrete slumped and bonded well, but at the top, there were areas of weakness where it passed through the mesh. That layer of concrete is part of what is being removed in prep for the shotcrete.

 

Next we are preparing the old (hand-applied) concrete to receive the shotcrete. I did most of the removal of faulty concrete by hand using these tools.

 

The completed membrane tuck installation!

 

Membrane tuck along the soil beam. The white is the sacrificial (pipe insulation) form that will be torn out after the concrete shoot. The form is held loosely with nylon string to allow the shotcrete to get in and surround it (we hope!).

 

The 'membrane tuck' wire model. This is for receiving the water-proofing membrane that will be overlaid, mid-range in the soil cover. The purpose is to have a place to tuck the membrane to keep water from flowing behind the edges down onto the building's surfaces.

 

We're going to shoot it next (once the old concrete is prepared, the membrane tuck is developed and installed and the blocking and masks are prepared)!

 

Completed view from above!

 

View of the inherent columns between rooms. Here you see the fine (lathe) mesh backing, the 2x2 layers (doubled on the open front side), from the perspective of where concrete will be shot.

 

Looking from the rear along the barrel arch root / beam.

 

Looking down from the roof at details of mesh and steel between rooms. These filleted areas serve as inherent beams and columns throughout.

 

2x2 layer nearly finished!.

 

Adding the 2x2 layer of roof mesh.

 

Treatment of the roots where the barrel arches butt (fillet).

 

Adding the 6x6 layer of roof mesh, here looking at the arch roots / beam.

 

Looking from the rear of the master bedroom, with vents and glass inserts.

 

Fine mesh reaching down into the arch roots (beam).

 

Fine inner mesh in place, here showing the sub-arches.

 

Finishing the fine mesh on the ceiling.

 

Starting up in 2017, getting there!

 

In the pantry, still only coarse 2" mesh. For 2017 we hope to finish the meshing (interior and exterior), and to prepare the final steps before ferrocement plastering.

 

 

Winter snow showing the roof details (rearward is coarse and fine mesh, forward is only coarse).

 

Detail around electrical boxes.

 

2nd layer moving into great room.

 

Starting 2nd layer of interior mesh (plaster lathe).

 

Inter-room venting and ship glass added as we go.

 

Details around sub-arch roots.

 

At the beams, the mesh is attached with concrete screws to provide a smooth contour.

 

Starting the interior coarse (2") mesh. Interior has 2" mesh, followed by plaster lathe. Exterior will have 6" mesh, followed by 2" mesh.

 

Tower's ladder fabricated and in place. Both layers of mesh behind the ladder needed to be placed before welding in the ladder.

 

Foggy view of our 'castle' as we transition into the next (2016) building season. In the coming period we need to get the final meshing completed (ceiling and roof), checkover all details, then setup for ferrocement plastering.

 

With the steel work complete, 9 bundles (tons) of rebar were used throughout (inclusive of foundation)!

 

A light snow really shows off the structural steel work!

 

Working the windscoop tower interior meshing.

 

Meshing the remaining towers -- here the chimney with the mesh layers flaring for lapping with ceiling mesh later.

 

Note ground screw protection (from the concrete later). Modeling clay was also used to plug the conduit terminations to protect against rain and insect intrusion.

 

Completing the electrical conduit runs into the ceiling/roof.

 

Bottle fill of soil beam complete. The 'thatched cottage' look we were hoping for turned out well we think. We estimate 2000 bottles were used as infill throughout the structure (recycled of course!).

 

 

Meshing and bottle fill of soil beam. Bottle infill used to reduce concrete needs. Note fence receivers are in place (don't want anyone running off the top!).

 

Tower structural infill complete.

 

Welding of capping ring complete, touching up the primer coat.

 

 

Windscoop ring placement.

 

Windscoop tower in-fill. Note scaffold and pulleys.

 

Equipment fitting and verification (vent box, exhaust hood, etc.).

 

Internal meshing of skylight and venting.

 

Building the bathroom skylight and venting.

 

Roof bars cutout, ready for meshing.

 

Building the bedroom skylight tower (not cutout yet).

 

As I was finishing up the season, I heard our resident (acorn) woodpeckers making louder drilling noises than usual. Turns out they were trying to drill out my inspection holes(*) and filling the voids with acorns! I can't imagine what their beaks (brains) look like. I've noticed since then that they are now sticking acorns in the open steel tubes of some window frames. Oh well, it's organic...

(*) I drilled the inspection holes to examine the 2011 concrete tests. The voids are the result of the lathe not allowing concrete to fully penetrate. The design was changed to have (fine) lathe mesh on one side only; and the identified voids will be filled with grout.

 

The end of the (2014) building season and the 3 roof sections complete! Over the winter (weather permitting), the towers will be brought up to full height and capped and the utility conduits in the roof installed. Next year I will mesh the roof and prepare to plaster the structure!

 

A view of the 3rd section from underneath. Here you can see the base for the fireplace / chimney tower in place.

 

Nearing completion.

 

Adding circumference rings to the tower.

 

Longitudal infill, as seen from the tower perspective.

 

Another view of the tower risers / half-arches.

 

Bringing the tower risers up. These are half-arches (the tower bisects what would be a normal contiguous arch).

 

This roof section also includes a large tower at the rear that will be a wind scoop (collecting and bringing fresh air into the structure). Here I am building up the support beams for that tower.

 

Starting the center roof section. This one is more of a typical barrel vault but still tilted (front-to-back). It is also covers the largest open span in the house (roughly 32' long by 22' wide at the floor).

 

The completion of the 2nd roof section.

 

My 'helping hands'.

 

The latitudal arches are complete, starting the longitudals.

 

Starting the eastern roof section. This one is a rotated (and tilted) arch!

 

Your's Truly testing out the roof (flexure, etc.). All 2x4 supports were pulled first to fully assess the result.

 

The first roof section is finished!

 

The longitudals are complete, as are the connections to the interior walls. Here is a view from the underside. For the wall connections I used curved pieces to allow joint flexure (versus puncture of the roof FC membrane) as the FC plaster is applied.

Notice the bullet-cylinders in the arch rebar along the top-center -- this is a splice. I needed these to extend the standard 20' rebar lengths out to lengths reaching 33' needed for the arches. For further info, go to Rebar Splicing.

 

Starting the longitudal in-fill.

 

 

 

Once an arch bar is in place every ~5 feet or so, longitudal spines are added along with a support to help keep the shape and slope.

 

Interesting curves ahead!

 

And with 2014 I am starting the roof! There are 3 tilted barrel arch section. This one (the west) is also a segmented arch (variable width). Here I am starting with the latitudal (cross) arch bars, then next I'll do the longitudals. A section is completed with shear bars then connections (and in-fill) to the interor walls.

 

Finishing the season (2013) with the wall meshing, frames, conduits in place.

 

 

Here is a closeup of the mesh layers (looking at a section of the front porch where walls and roof come together).

 

Side view with the window 'eyebrows' in and most of the exterior meshing finished.

 

The meshing is coming along. Here I am installing the center clerestory (the hanging tarp is used to block sparkes while welding and cutting).

 

Trying out the finished door and frame. After fitting, the door will be removed and later plastered with cement.

 

Fabricating the main entry door and frame.

 

Fabricating one of the clerestory frames.

 

Close-up view of a section where walls drain showing the mesh layers and conduit.

 

The atrium is completely meshed!

 

A close-up of the modifications (via cutting wheel) made to the pliers for twisting wire.

 

These are the tools I use for meshing. The black gun-like tool in the middle-left is a Bostich ring gun -- very handy tool for joining meshes.

 

This season (2013) we are doing the utility conduits, finishing the window/door frames and meshing the walls. In places where there is a large, non-critical structure (like the solar collector mounts), I am filling the space with bottles to reduce the final concrete needs.

 

There was no building activity for the 2012 year...

 

Images of the completed work before shutting down for the 2011 Winter.

Note from concrete tests -- the lathe (fine, outer) mesh won't allow you to trowel or shoot through so we removed the fine mesh from one side.

 

 

 

 

 

Cured and unveiled!

 

Here we are doing one of the window 'eyebrows'.

 

Pouring (columns and beams) complete throughout.

 

Here the main columns throughout are finished and we've just finished the west beam, preparing to cover it for the cure.

 

This is the form-less method we used for the columns and beams. It is poured from the top, then the 'oooze' is screeded.

 

Here we've completed a 3' high section around the rear perimeter to keep out mud during the coming winter. Note the burlap covers for curing.

 

Working on the east retaining wall plaster. Note bottle fill started in the soil / edge beam.

 

The left (utility) entry completed, which served to test the methodology for the rest of the structure.

 

 

Here we are test plastering a region to see how effectively we can get the plaster through all of the layers. As it turned out, it is nearly impossible due to the quality of sand we were using and the mix. We ended up pulling off the final (stucco) mesh layer on one side and things went smoothly from that point on.

In our revised approach, only one side has expanded (stucco) mesh (the other side's is replaced, when needed, with a layer of 1x1 or a 2nd, offset of 2x2 mesh). For the formless pours (columns, beams), the expanded (stucco) mesh is retained and used to contain the pour.

 

Mesh in place for this year's pours and plastering.

 

Closeup of a fully-meshed column (stucco, 1x1, 2x2 layers over rebar).

 

Stucco (final) mesh layer in place, note integrated gutter over entrance.

 

Decorative glass inserted into the stucco mesh final layer.

 

 

 

Running the electrical conduit and boxes.

 

Column meshing detail (2x2 and 1x1 in place).

 

Solar oven is in and the kitchen column has the first layer of (2x2) mesh.

 

 

A bit of free-form buildup on the living area wall (tree branching to compliment the column).

 

2x2 meshing at column fill areas.

 

Beginning the column meshing. Here we use bottle fill to reduce concrete needs in non-structural areas.

 

Extending the retaining wall at the left (utility) entrance.

 

Summer, 2011; After adding the roof arch ties to the beams.

 

The completed peripheral structure as we prepare to shut down for the Fall (2010) rains. Over the Winter, we'll be finishing the steel frames for the doors (ferrocement/steel) and clerestory windows (3, at the arch peaks) and get them in place. I also need to mount the solar wall oven (already built). As the weather improves we'll be meshing and plastering the beams and columns (to give the core strength), then beginning the roof (barrel arches). Remember, that with the exception of the front and atrium faces, the structure will be buried. Incidentally, the total waste from construction to date (including the foundation) would probably fit in 5 or 6 five-gallon buckets!

 

 

Taking a break...

 

 

 

Beginning the roof edge beam / soil wall. The beam will be rubble filled (old cans and bottles) internally to reduce concrete usage (and sticking with the ferrocement construct). This technique will be used elsewhere in the structure where we want the bulk but don't need the mass or compressive strength...

 

 

The west end, with the door cutout and the entry porch / retaining wall framed.

 

 

Beginning the west entry and solar collector (hot water) faces.

 

The 'bird cage' (entry closet).

 

Here you see the 'eyebrows' over one of the windows (all windows will have them). The purpose is to allow direct winter sunlight but no direct summer sun. In window frames like these, I'll be inserting commercial aluminum-framed sliding windows.

 

 

Atrium framing completed (the loops hanging down are for a plant cross hanger).

 

 

 

Building the atrium window frame complex in place. The glass will be from recycled patio doors (double pane tempered).

 

Showing beam interconnectedness.

 

East retaining wall and column/wall inter-tie.

 

 

 

Extending side walls around.

 

 

The front entry porch framed up.

 

 

Fabricating the frames (windows, vents, doors, etc.).

 

Another view...

 

Rear wall between the primary beams with wind tower forming started. Also, the smaller 'hanging' beam that ties the two longitudal beams can be seen just before the upper curve of the wall.

 

Completed east longitudal beam and intersection with front wall.

 

Bending the arch bars.

 

Rear wall interconnection.

 

Another view... The longitudal beams will serve as the base for the barrel-vault roofs.

 

Completed west longitudal beam and diaphram walls. Note that the columns will be mesh covered and plastered, then poured with conventional concrete (to increase compressive strength of the columns). The beams will be also be meshed and plastered but their fill will be with lightweight concrete (perilite replacing aggregate). This is a takeoff on one of the historical applications of 'ferroconcrete' -- where a ferrocement exterior was used as the 'form' for pouring (no wood) when higher compression or mass was required.

 

Infilling the west beam.

 

The west longitudal beam started (the east beam & arch in the background).

 

Developing the rear and diaphram walls, including installing the first (internal) door frames.

 

We really got going in July (after the last of the rains and the gardens going). Here we are starting the east longitudal beam and arch.

 

Frame steel bent and ready for welding (doors, etc.)

 

The buttress column by the kitchen

 

We took the 2009 summer off from building for various reasons. Here, in March (2010), we are raising the first columns between the rains.

 

Covered for the 2 week (minimum) cure.

 

 

The completed foundation!

 

...and finishing it.

 

The 'team' pumping/placing the concrete...

 

The 6x6x10 mesh overlay and screed boards in place.

 

Warm, dry weather returned in January (2009) and we got to work. Here, the radiant tubing is being placed (we used Pex-Al-Pex tubing).

 

We had hoped to have the foundation poured before Christmas 2008, but an artic storm and 6" of snow put a crimp on that. Here we have only the radiant tubing and the 6x6 mesh left to do...!

 

The beams, columns and center steel is in. Working on the inter-ties.

 

 

The rebar bending table we designed/built got a lot of use.

 

The main entrance porch. Box in center is the form for the mud-grate. A drain is in the front (facing you) while on the right side is the air intake for the masonry heater.

 

The atrium formwork and reinforcing steel in place. It faces east and will have a gravel floor to support citrus and similar plants needing freeze protection.

 

The steelwork for the eastern retaining wall (canterlever-type).

 

View showing the lower level rebar for the western transverse beam and masonry heater.

 

The western or utility entrance porch and integrated retaining wall. The box on the right is the mudgrate which also contains an airfeed to the root cellar.

 

Lower level beam rebar work in place.

 

Working on the tie beam (lower level steel).

 

Walls marked and ready to lay in the steel!

 

The vapor barrier / insulation in place.

 

The completed foundation base, utilities and formwork!

 

Laying the top-level gravel base and final sand layer.

 

Before laying the gravel base for the upper (non-beam) areas, the electric conduit is placed.

 

Utilities and majority of formwork is in. Here the gravel base has been placed in the beams and we are bringing in the base for the upper layer.

 

Laying in the utilities (in this case, DWV and water).

 

Ah, now that is becoming recognizable!

 

Starting the formwork.

 

The beams have been defined and utility points marked.

 

The foundation work begins!

 

During the 2007/2008 winter, we worked on finalizing the house design and associated calculations and documentation. Preliminary drawings (a minimal set) were submitted to the building department in February but they sent us back for more details. We finished the final plans in mid-May and submitted them. We received approval in mid-June (2008).

 

Covering the temporary drain lines with gravel to over-winter the site. Not shown was the upper diversion as well as jute netting over the exposed hillside.

 

Routing the temporary site drainage following excavation to the approximate floor (rains were already starting).

 

 

The formal site excavation begins! (Fall 2007)

 

An early clay model of the house.

 

The old clawfoot tub, lovingly restored and refinished by yours truly (we couldn't resist giving the claw feet's nails a bit of gold trim while we were at it)!

 

We are constantly 'scrounging' discarded wood to recycle into our house. Here are plywood sheet and milled redwood that came from the Hopland area that was so badly hit by the January '06 floods. Of course there is a bit of time to pull the nails and trimming out bad parts but it does save money and reduce landfill!

 

Spreading / leveling the gravel for the road's terminal road at the housesite.

 

The 'terminal loop' (road) being graveled.

 

Early morning fog lapping at the excavated house site.

 

Grading the homesite with the house excavation in the foreground

 

Clearing the homesite

 

Clay and paper topographic model of the homesite. The red area is the excavation for the house, the greenhouse is the domed structure in the front, storage is behind that, while the blue is the photovoltaic mount and work structure with our camper parked beside it.

 

 

Conducting topographic studies for the homesite (water-filled homemade measuring tool)

 

The House Design & Construction

The house will be constructed out of ferrocement, which lends itself to free-form structures, and embedded in the end of an Oak lined knoll (i.e. partially underground with a 'living roof'). Underground siting of a house (or any building) brings with it noise and thermal insulation, and leaves the land above it available for use as gardens, recreation or to let nature reclaim it.

Ferrocement is a steel-reinforced concrete most often associated with ocean-going ships or with sculpture. It is unlike conventional reinforced concrete in that the amount of concrete used is much less and the steel much higher (but thinner). Concrete gives the compressional strength while steel gives the finished structure the tensile strength. World Emergency Management organizations lists ferrocement construction as one of the few building methods suitable for earthquake, wildfire, hurricane and tornado prone areas.

In our case, our interest is in building a free-form house, more like a sculpture, that will survive 200-500 years. It doesn't make sense to build with materials that won't last 20-50 years as that is not sustainable, even with the greenest materials and intent. More specifically, we look at the embedded energy per ton (or GH gasses per ton) divided by the expected lifetime. The resulting 'figure of merit' says a lot about the way we build today.

Given that wood quality has deteriorated so much due to the tree farm practices (experts now recommend only using it indoors), and the locality problems with materials such as strawbale, clay, etc., ferrocement makes sense. Further, steel is one of the most recycled materials today, with a relatively low embodied energy. Concrete, made predominately of clay and lime, and when used with the addition of up to 70% pozzolons (e.g. flyash), is a basic material also with a relatively low embodied energy. Ferrocement construction is material cheap (relatively) and labor intensive -- just right for an owner built home.

For illustrations of ferrocement construction (and other designs that have inspired us), see the SkyView Project House Ideas page.

The following documents detail more specific aspects of the house design from the perspective of the Building department (these documents, along with the plans and calculations that follow were part of the permit submission):
Adobe .pdf format
House design notes
Title 24 compliance (California energy issues)
Site, soils

 

The House Plans
Adobe .pdf format

Site, sun_wind
Site, elev. fit
Site, plan fit
Site, excavation
Site, surface drainage

Plan, overview
Plan, face elevation
Plan, southeast elevation
Plan, southwest elevation

Calcs, loads
Calcs, foundation
Calcs, RC constructs
Calcs, FC constructs
Calcs, arches

Foundation, overview
Foundation, details #1
Foundation, details #2
Foundation, details #3
Foundation, details #4
Foundation, details #5
Foundation, DWV
Foundation, water
Foundation, electrical
Foundation, radiant

Structural, overview #1
Structural, overview #2
Structural, overview #3
Structural, FC columns and beams
Structural, FC general #1
Structural, FC general #2
Structural, details #1
Structural, details #2
Structural, details #3
Structural, details #4
Structural, details #5
Structural, details #6
Structural, details #7
Structural, details #8
Structural, arch details #1
Structural, arch details #2
Structural, arch details #3
Structural, arch details #4
Structural, arch details #5

Interior, masonry heater #1
Interior, masonry heater #2
Interior, solar oven
Interior, misc #1
Interior, misc #2
Interior, ventilation and lighting overview
Interior, ventilation (root cellar)
Interior, plumbing
Interior, radiant and hotwater #1
Interior, radiant and hotwater #2
Interior, DWV
Interior, electrical

Exterior, final appearance

Concrete and Plaster mixes

 

Additional Reading for Those Interested:
('*' = highest recommendations)

A Pattern Language, Christopher Alexander, et al, Oxford Univ. Press, 1977
*Your Engineered House, Rex Roberts, M. Evans & Co., 1964
The Earth Sheltered Owner-Built Home, Kern, Mullein Publishing, 1982
Underground Houses; How to Build a Low-Cost Home, Roy, Sterling, 1979
The Earth-Sheltered House; An Architect's Sketchbook, Wells, Chelsea Green, 1998
*Earth Sheltered Housing Design; Guidelines, Examples and References, Van Norstrand Reinhold Company, 1978
*Passive Annual Heat Storage; Improving the Design of Earth Shelters, Hait, John & Rocky Mountain Institute, 1983 & 2005
The Complete Book of Underground Houses; How to Build a Low-Cost Home, Roy, Sterling, 1994
The Underground House Book, Campbell, Garden Way, 1980
How to Build your own Underground Home, Scott, Tab, 1979
Underground Designs, Wells, Brick House, 1977
*From the Earth Up, The Art and Vision of James Hubbel, Rigan, McGraw-Hill, 1979
Building with Vision, Optimizing and Finding Alternatives to Wood, Watershed Media, 2001
Handmade Homes, The Natural Way to Build Houses, Boericke and Shapiro, Delacorte Press, 1981
Zoomorphic, New Animal Architecture, Hugh Aldersey-Williams, Harper Design, 2003
The Ferro-Concrete Style, Francis Onderdonk, Hennessey & Ingalls, 1998 (1928)
*The Hand-Sculpted House, Evans Smith and Smiley, Chelsea Green, 2002
*Places of the Soul; Architecture and Environmental Design as a Healing Art, Christopher Day, Thorsons, 1990/1995
*Concrete Design, Gaventa / Beazley, Octopus Publishing, 2001
*A Shelter Sketchbook, Timeless Building Solutions, Taylor, Chelsea Green, 1983
*The Natural House Book, Pearson, Fireside, 1989
*Living Spaces; Ecological Building and Design, Konemann, 1998
*Home Work; Handbuilt Shelter, Kahn, Shelter Publications, 2004
*Earth to Spirit; In Search of Natural Architecture, Pearson, Chronicle Books, 1994
Ferrocement Model Code; Building Code Recommendations for Ferrocement, International Ferrocement Society, www.ferrocement.org, 2001
Ferrocement Housing Prelude, Hemant Vaidya, Om, 1994

Note, many of these books can be obtained from Charmagne Taylor at Dirt Cheap Builder (aka Taylor Publishing)