The 12 Southern Councils have now agreed on the Southern Tasmanian Regional Land Use Strategy 2010-2035 and it is with the Minister for Planning to be signed into existence. The Strategy requires that all future residential development in the Greater Hobart Area conform to a density of 15 Lots/blocks to the hectare. That means that the average lot size will become 450 m2 rather than what was previously known as the quarter acre lot at around 800 m2. Half of all of the land development in the Greater Hobart Area must be infill development within existing urban areas with the other half being in Greenfield developments.
Other states have had this requirement for 20 years or more and have produced estates with a high level of residential amenity. They have developed rules and principles for higher density housing and rules around Environmentally Sustainable Development. If Tasmania starts into building higher density housing without such rules chaos will ensue. The state government must act quickly on preparing these rules otherwise there will be big trouble ahead.
Environmentally Sensitive Development (ESD) is where all development of land in all areas for all uses is brought into existence under the best possible environmental principles. It is about:
1. Creating subdivisions and infill lots that allow people to build environmentally sensible dwellings.
2. Protecting residential development from damaging sensitive eco systems.
3. Only building dwellings that perform well in the local climate.
4. Good urban design with housing choice and with some affordable housing.
5. Efficient social and commercial services and well designed open space.
6. Cost effective infrastructure and landscaping.
7. Water sensitive urban design (WSUD).
ESD sometimes refers to slightly different words such as sensitive rather than sustainable and ecological rather than environmental or design instead of development but it basically comes down to the same thing. In land uses planning environmental, economic and social elements are considered. ESD focuses on the environmental part of that model. It is less about climate change and carbon emissions which are more global issues. ESD is more about what we are doing in developing our own local urban environments.
In this article I will concentrate primarily on the first three components as listed above as it is critical that attention is given to them in Tasmanian at this point in time where infill and greater housing densities are high on the agenda.
Creating ESD Subdivisions
In the past many old subdivisions have had large blocks (800m2) known as quarter acre lots (7 to 10 per hectare). The Southern Tasmanian Regional Land Use Strategy (STRLUS) has shown that if this past land use was to continue Greater Hobart would require 4,000 additional hectares of residential land. This would be half the size of Greater Hobart again. This level of consumption cannot continue wasting many millions of dollars on infrastructure, transport costs and the provision of services. The STRLUS made up of the 12 southern councils has agreed that the General Residential Zone across the region should have a density of 15 Lots to the hectare meaning that the average lot size is 450 m2. That generally equates to a lot that has a 15m frontage and a depth of 30m. Victoria has had this requirement for at least 20 years. The STRLUS has also agreed that there should be an Inner Residential Zone with a density of 25 dwellings per hectare to allow for infill development. To achieve this density there needs to be a number of medium density developments with town houses and units. It is agreed that 50% of new lots in the Greater Hobart Area will be infill out over the next 25 years.
Now this is a necessary and important change proposed for future residential development in Greater Hobart. It will provide greater housing choice and more appropriate housing for the aging population of Tasmania. Almost all urban residential development in the other states is at this density and there are many examples of such areas with a high level of residential amenity. Indeed I have been involved in planning a number of such developments in a number of states and in training others in good urban design for such estates.
However, this move to higher densities could be a disaster if developers and builders continue to try and build the same old dwellings. There have been numerous stuff ups along the way in other states as builders have learnt to build at these densities. The Tasmanian Minister has just announced a new code (PD 4) that streamlines the approval of a single dwelling on a standard lot. The Minister says this is a great leap forward but when the Regional Strategy comes in there will be very few standard larger lots that he is referring to in the Greater Hobart Area. The southern councils are running well ahead of the state.
Basically, a new set of urban design principles have to be followed if higher density developments are going to give a high level of amenity. I obviously cannot give all of these principles here but here are a few examples.
The principles have to start from the layout of the subdivision. It is important to maximize the number of lots with a long east west axis so the dwellings can have adequate northerly facing living areas to catch the sun. The roads have to form regular rectangles to achieve this.
Cul-de-sacs are not acceptable as only half the lots will be East West. Builders need to build within a foot print so that they do not block their neighbor’s solar access. And so the list goes on.
Higher density housing bringing wider housing choice may well be introduced in Launceston. It may not be needed in North Western region of the state.
Protecting Residential Development from Damaging Sensitive Eco Systems
There is always a bit of a trade off in wanting to maintain sensitive eco systems within urban areas and of course there are some areas that are so important that they must be maintained. The trade off is that the more you protect in the city the more urban development will spread out over the landscape external to the city. It is inevitable that some trees will have to be cut down to bring about infill and sensibly redevelopment of existing urban areas. However, there are ways to compensate for the removal of trees. I have managed a large development in Victoria where we collected seeds from a site and propagated them and planted them throughout the new subdivision. So a balanced approach is needed on this aspect.
Only Building Dwellings that Perform Well in the Local Climate
This seems to be a self evident statement. But why in Tasmania is it the responsibility of the prospective owner to work through these elements themselves. In Tasmania there is only a star rating system that builders have to meet which produces houses that many people would see as inefficient? In other states regulation has moved well beyond this approach. In NSW for example there is a State Environment Planning Policy (SEPP) call BASIX that dictates a range of things that are not acceptable in a dwelling. For example residential dwellings are not allowed to be built without eaves. More importantly such systems educate builders that might only build a few houses a year.
Now a lot of readers will already know about the features needed to have an environmentally sustainable home. Things like correct solar orientation, shading, thermal mass and solar heating, energy efficiency, full insulation, avoiding deep verandahs on the northern side, zoning the inside of a house and energy effective windows that prevent temperature exchange. I have personally built a house out of aerated concrete otherwise known as Hebel blocks which performed exceptionally well in the extreme Canberra climate.. Most of these environmentally sustainable housing issues are design issues and do not necessarily increase the overall price of a new house.
It is of course a little harder to make existing older houses more environmentally friendly. However, there are retrofit things that can be done to older poorly designed buildings. Insulation can be pumped in to wall spaces and into roof spaces. Windows can be easily re-glazed with single panel energy efficient glass. Shading can be introduced that lets the sun in during winter and not in summer. It is also possible to have large stainless steel reflectors on the southern side of the house that delivers heat and light into southern rooms.
There are several things that inhibit the wide spread introduction of energy efficient housing in Tasmania. The first is that the majority of dwellings constructed in Tasmania are built by small builders that build four or so houses out of the back of their ute each year and have not changed their building methods from those of previous generations. Until the government brings in regulations that make them change they will continue to build poor quality housing. They also build expensive housing because, building so few dwellings does not enable them to buy materials in bulk and hence do not achieve economies of scale as builders do in the other states. Secondly it would also appear that when the government builds affordable housing for low income families it does not maximize the environmental efficiency of its new dwellings.
The other four Elements of ESD
Good urban design does not necessarily cost more. It depends on the skill, experience and attitude of the planners involved. Providing housing choice in urban areas is also particularly important in the case of an aging population. Too many older people live alone in what was the family home and cannot move because there are not suitable dwellings for them to move into. This is a problem of wasted resources not only in Tasmania but across the nation.
Now I have not focused on the latter four elements of ESD although they are still vitally important. I could have expanded out this article out by ten times for there is a lot more that can be said about ESD. I am also sure that there will be individuals looking at this article that know more than I do about particular aspects of ESD and that have built energy efficient housing themselves like I have. However, it appears that there are only a handful of individuals that are taking ESD seriously. I estimate that only 10% or less of existing dwellings in the Greater Hobart Area are energy efficient.
Builders and the Government are still building woefully inadequate housing for people to live in. The Tasmanian people and the government have seriously neglected this important element of sensibly protecting the environment. This should be core business for the state government. How is it that Tasmania is supposed to be clean and green and have a lot of people that are fighting to save the environment but few have focused in on effective Environmentally Sustainable Development?