Home builders in Blackmans Bay

Blackmans Bay carries an Attenuation Area for the Blackmans Bay Treatment Plant, with a 300 m odour buffer. That is the kind of mapped constraint that never comes up in a conversation about house designs and matters enormously to anyone living in one. It is also the clearest single difference between building here and building in Kingston or Margate, which carry attenuation buffers of their own from entirely different sources.

An attenuation area is a buffer around something that emits

Where an attenuation area applies, sensitive uses — housing among them — are assessed with regard to the emission the buffer exists for. In Blackmans Bay that emission is odour, and the buffer distance is 300 m from the treatment plant. Whether it reaches a particular block is an address check and the answer is binary. It is worth running before you buy rather than after you have lived through a still summer evening, and it is exactly the kind of thing a planning search returns and a real estate listing does not.

Landslide mapped by slope angle

Under the Kingborough Interim Planning Scheme 2015, landslide hazard here is mapped as remaining areas slopes 11–20 degrees and slopes greater than 20 degrees. That is a more literal mapping than the low/medium bands used elsewhere in Tasmania, and it is useful because you can read your own block against it. A block inside a mapped band must have a geotechnical report before the building permit — which adds cost and, more importantly, time to the front of a project. On slopes over 20 degrees, expect the report to drive a stepped or piered footing solution rather than a slab on ground.

Waterway buffers at four widths

The Waterway and Coastal Protection Area is mapped at 10 m, 20 m, 30 m and 40 m buffer widths in different parts of the suburb. Those buffers restrict what can happen close to a watercourse or the coast, and on a block with a creek line through it the 40 m band can take a substantial share of the developable area. It is a siting constraint rather than a construction one, and it belongs in the site plan from the first sketch.

Coastal inundation measured against sea level rise

The Coastal Inundation Hazard Area here is described in terms of vulnerability to the highest astronomical tide now, and to a 0.2 m sea level rise. That is a specific and checkable statement rather than a general warning. A Coastal Erosion Hazard Area is mapped as well, in the acceptable hazard zone landward of the likely and possible natural recession limits. Both reach siting and levels on waterfront land, and neither applies to most of the suburb.

Three zones, including Rural Living

General Residential, Low Density Residential and Rural Living are mapped, and a Rural Living Zone Area A overlay identifies where the rural living provisions apply. On rural living land the cost structure changes: driveway length, service runs, water supply and possibly on-site wastewater. A builder whose recent work is all on serviced General Residential lots here has not necessarily priced that.

Biodiversity and scenic landscape

A Biodiversity Protection Area and a Scenic Landscape Area are both mapped somewhere in Blackmans Bay. The first reaches vegetation removal and siting where identified values are present; the second reaches how development sits in a landscape that has been identified as scenically significant, which is a bulk-and-visibility question rather than a facade one. On an elevated block with a view, the second is the one that can surprise you — the view that makes the block desirable also makes the building visible.

Bushfire-prone areas

Bushfire-prone areas are mapped in Blackmans Bay. A block inside the mapping requires a bushfire assessment, and the outcome drives both the construction standard and, in Tasmania, the hazard management plan that accompanies an application. Because this interacts with the biodiversity and waterway protection mapping — the vegetation a bushfire assessment wants managed may be vegetation another code protects — it is worth resolving the two together at site-planning stage.

What to establish first in Blackmans Bay

Whether the 300 m treatment plant attenuation buffer reaches the block. Then the slope band, because over 20 degrees the geotechnical report is on the critical path. Then the waterway buffer width if there is a watercourse. Then bushfire, biodiversity and scenic landscape as a set, and the coastal mapping if the block is near the water.