Time to unveil the project

I realise I have been a bit of a tease with descriptions of the project and our rationale for upping sticks and going bush. This is the post where I reveal all!

To start with, there are some 3D images that were produced by our designer when she was teaching herself a new program. 

The house will nestle into the hillside, but it does give a general idea. The outer cladding will  be a coated metal called Colourbond in a very dark charcoal colour called Monument. The roof will be of the same material, except it will be a pale silver called Shale Grey. The roof profile will be almost flat; there needs to be a three centimetre drop to allow the rain to run off. There is an external gridwork which will be in Australian White Cypress, a sustainably produced timber. This will be left raw and will soften and silver over time. It is also not a desirable food for cockatoos, so we won't need to worry about them coming to eat the house. In some ways, the gridwork reminds me of Japanese furniture. The designer developed this idea without knowing that our furniture is of this style.

The triangular spine running down the middle of the roof has two main purposes. Firstly, it is slanted to the correct angle for our solar hot water system and also our solar power array. There are also three skylights; two for the bathrooms and one for the laundry. These rooms have south facing windows and the skylights will vent air on hot days when the cool change comes in from the south. The laundry skylight will also have a retractable clothes rack which will allow us to hang our washing up to dry on wet, wintery days. I like freshly line-dried washing, but it is good to know that we have another option if we need it. The one we have chosen is produced locally in Castlemaine by Usethings. At the far end of the laundry, we will have a small larder which will be well insulated. We will store all our preserves and wine, as well as any vegetables that need to be kept in a cool, dark place.

The house is long and skinny; 37 metres long and only five metres wide. We wanted to avoid having hallways, so each room flows into the next. All main rooms will have windows facing to both the north and the south. The northerly aspect allows the sun to penetrate fully to heat the concrete slab in winter and will mean that we need almost no heating. The southerly windows will give the view across the valley.

The house will have two bedrooms and a large study and two bathrooms. We will have an open plan kitchen, dining and living area.  Although the house is narrow, the scale of the rooms is just right. We will have three metre ceilings, so the rooms will not feel pokey. 

The last grid section of the house is a walk in wardrobe. It will be entirely open with a false wall hiding it from the main room. We intend to use this for all storage of clothes, bed linen, towels, and fabric items such as our yoga bolsters and our suitcases. It will have a window at the closed end which will ventilate it fully to the northerly windows. All items will be stored on wire shelving, open racks or Elfa baskets. I have to say that this wardrobe is my dream come true. At the moment I have seventy centimetres of hanging space in my wardrobe.

This is the view from the northeast.
Our bedroom, wardrobe and bathroom will be at this end of the house. 

This is the view up towards the house from the south west.
It shows the carport and shed attached to the building.
We needed the extra roof space to collect the rain water on
which we will be dependent. The location of the shed and
carport will provide protection from the hot westerly afternoon sun.

This view is from the southeast. We will have a
pergola and outdoor area out of the sun. Remember
that we have the sun in the north in the Southern Hemisphere!

Here is a view from the northwest.

Sustainability

Most people who have been nagging me to write this blog are interested in the idea of sustainable design and how we will be applying these principles. Our designers have worked to achieve a house that scores about 8.6 stars out of a possible ten. It is mandated that all houses will be six stars in our state. A ten star house is one that is entirely passive in its inputs and outputs and is constructed in a way to offset all the elements of the construction. It tends to be more of a theoretical concept because of the high costs of building. 

There are various features that will make the house passive:

1.   Thermal mass. Our house will be built on an insulated concrete slab. The north facing windows will allow winter sunlight to penetrate the full width of the building to warm the slab and it will retain heat through the day. The angle of the sun in summer will be sharper, so the interior of the house will not be heated in the same way. Blinds and a pergola will provide shade when it is required. The concrete in the slab is a more environmentally sustainable product with a percentage of flyash. We will have little need to heat or cool our house except after a run of very hot days where the temperature does not drop overnight. I will write more about heating and cooling at a later point. If you want a more expert explanation  of thermal mass and how it works, go to http://www.yourhome.gov.au/technical/fs49.html

2.    The house will be air tight to prevent heat loss or gain depending on the seasons. There is an airlock at the front and back doors to maintain the interior environment during extreme heat and cooler weather. The house will be heavily insulated with a wool-based product and there will be several other layers of insulation and still air in between. When cool changes come in summer, they usually come from the southwest. The house is positioned so all windows can be opened to catch the breezes and vent hot air out of the building. Three skylights will allow this to occur in the two bathrooms and the laundry as they do not have direct northerly windows.

3.   Windows are always the weakness in the fabric of a building in terms of heat loss and gain. We have some floor to ceiling windows in the living area, but most are not full height to maintain the integrity of the insulation. Our windows and skylights will be double-glazed which is unusual in Australia.

4.   We will collect all of our water and store it in two 37,000 litre rainwater tanks. We will be entirely dependent on an average rainfall of 500 millimetres per year. We also have a ten thousand litre tank for garden use which will collect water from the chicken coop roof. In addition to this, we will also have to provide another ten thousand litre tank for bush firefighting purposes.

5.   All of our black and grey water will be treated on our property with a worm farm system. http://www.wormfarm.com.au/domestic/ The water then drains into a holding tank and as it overflows, the filtered water runs though the swales and leaches down through the soil. This water will be odourless, and contain worm castings and eggs to benefit the soil.

6.   We will be investing in a large solar array that will run along the spine of the house. This will have a grid exchanger so we can send power to the electricity grid during the day and draw back in the evening when we might require it. This is not a cheap option and electricity companies are no longer paying a fair tariff for the excess electricity, however, there are more important reasons to set up the system than simply cost.

These factors, coupled with our intention to grow our own fruit, vegetables and keep chickens, should result in a smaller environmental footprint than we have at the moment. 

We also have to maintain good weed control to allow the native wild flowers to flourish in the poor soil. In this photo, I am hard at work with the mattock digging out blackberries, which are a curse in the bush because they are so invasive.