Retrospective - Design vs. Reality

Design Performance has greatly exceeded expectations

Studio Nimbus turns out to be a very comfortable home in a beautiful lush tropical environment. Design features for temperature, air flow and humidity control have exceeded our expectations. Generally the passive design and time of day you open the place up keeps the interior climate ideal. Interior natural light levels are good due to direct and reflected sources. The high level exhaust fans, used sparingly swap warm air for cool or the reverse. The current design would work nearly as well without any ceiling fans at all but they do help circulate warm dry dehumidifying air from the wood stove.

The condensation that we though would be an issue did not eventuate as the double glazing, insulation and wood stove worked together so well to keep the interior comfortably dry.

Electricity consumption is less than anticipated and the single wall mounted duct for all outlets and switches has been easy to adapt to. Our biggest electricity cost is refrigeration currently a fridge and a freezer are needed to keep emergency supplementary food stocks over the wet season.

Future Plans for Energy Independence

Seasonal long periods of cloud cover and tree shading mean solar power and solar water heating are technically feasible but financially impractical. In our "Cool Season" we can get more than 10 days of heavy cloud in a row, a couple of days of sun then another cloudy period. The size and cost of a battery bank, that would give total grid-independence, pro-rated over a decade would be twice the current annual cost of full-time grid connection. We anticipate the "connection fee" of our monopoly electricity supplier will increase at a rate in excess of inflation , off-setting some or all of the benefit of drawing from the grid during long periods of heavy cloud. Ideally we would like to use solar panels. Using the panels directly for things like clothes washing / drying / baking / freezing on sunny days; using the battery bank during low draw periods such as in the evenings and drawing from the grid during stormy times. A smaller independent battery bank would supply an additional margin of safety during the cyclone season.

Hydro-electric power is a definite possibility and a challenge. We have sufficient flow and head, but the local permanent stream level can rapidly rise by 3m following intense rain. A proof of concept trial using a small diameter siphon over a small headland, was not successful owing to the high internal friction in the small pipe. Further trials using larger pipe and maximising AC voltages are being considered. Bernouli's equation is needed for the siphon design. Generators and pipe need to be out of the flooding. Our current calculations indicate that two medium head devices and 37m of 100mm pipe would meet all our electricity requirements. It would be great to dump any excess power into the battery of an electric “water powered” car.

Re-purposing vs. Recycling

In the event that Studio Nimbus reaches the end of it's life close to 100% of the major structural components can be unbolted and re-purposed. The use of two people and a scissors lift for less than a week could reduce the sturcture to a simple reuseable slab and two durable re-useable "pods".

For example the main structural steel beams are connected by large galvanised bolts. They are all standard metric lengths.

The wooden rose gum flooring and silky oak end walls, since installation have appreciated so much in value that their removal for re-purposing would be profitable.

The structural insulated panels cross large spans and are held in place by Tek hex metal screws , so panels could be removed intact and either re-purposed as a whole or re-cut to smaller panels and reused. The steel is completely recyclable. The foam between the panels could be repurposed as packing material but cannot be completlely recycled at time of writing, however it is composed of the same material as foam coffee cups and work is in progress on future methods of complete recycling.

Re-purposing is much more energy efficient than recycling. Re-purposing requires incorporating connectors into the design that facilitate easy de-construction. The use of components to metre, half-metre and quarter metre lengths in new construction makes sense on many levels.

Why conventional housing construction methods / architectural designs in Australia are so completely devoid of re-purposing considerations remains a mystery.