Triplex Development – Zoning, updated

In my last post I introduced zoning and how to calculate the allowed housing density depending on the R codes. Well, that didn’t provide the whole picture, the minimum land is a little less than 10,000 divided by the R code

I am located in Western Australia where the planning of land use is governed by the Western Australian Planning Commission, the WAPC has allowed lower minimum land requirements then the  those obtained by using the standard R codes.

The reason for this is back in the old days, blocks where measured in the Gunter Chain, literally a metal chain consisting of known Links used to measure distances. 1 Gunter Chain is equal to 20.1168 metres.  Blocks of land were commonly measured out in multiples or fractions of the Gunter Chain, my 911sqm land is actually 0.9 chains by 2.5 chains. Now the problem with these imperial measurements, is it didn’t work well with the new metric system, the R codes being the later.

When the WAPC wanted to increase the housing density to allow owners of large blocks of land to build a duplex behind their existing home, at R20 many people with these 911sqm standard imperial blocks would not be able to implement this. This is one of the reasons why the WAPC decreased the minimum land to 440sqm.

The below is an excerpt from the State Planning Policy 3.1 Residential Design Codes.

As you can see the minimum land for R20 is 440sqm.
WAPC R-codes

Triplex Development – Zoning

In the last post I introduced my planned triplex development, I skipped over something, why specifically a triplex development?

This comes down to zoning, zoning is one part of the general council’s land use Planning Scheme, in simple terms, zoning determines the minimum land size a dwelling must reside on.

My land is zoned R20/R40, depending on what specific additional requirements are met for each.

Lets use R40, as this allows for more dwellings, to calculate the minimum land size;

1hector /40 = 10000m2/40 =  250m2

Therefore, each dwelling needs to sit on a minimum 250m2 of land.

My land is 911m2, so to determine the number of dwellings;

911/250 = 3.644 dwellings

hence a triplex development.

Triplex Development – Introduction

A few years ago together with the misses, we bought an old house sitting on a decent parcel of land, enough to build three houses when the time came. You can further read about the purchase on our joint blog, “Buying a house and making a home”.

Well the time has now come to start developing, as a first time developer and builder, there will be a lot of learning and experiences which I will document and share, and hopefully it will be useful for others in the same situation.

Some information on the land;

  • 3×1 double brick house
  • Land area 911 metres squared
  • Approximately 18 x 50.3 metres
  • Zoned R20/R40
  • Purchased for $500k

Cloverdale lot diagram and zoning

Calculate Stamp Duty with Excel

A quick post of how to calculate the Stamp Duty of a property with Excel, in my example I am using the Western Australia Residential Rate Dutiable value.

Stamp Duty
Cutoff [$]  Rate [%]  Duty [$]  Formula
0           1.9       0    0
120000      2.85      2280      =C3+(A4-A3)*B3/100
150000      3.8       3135      =C4+(A5-A4)*B4/100
360000      4.75      11115     =C5+(A6-A5)*B5/100
725000      5.15      28452.5   =C6+(A7-A6)*B6/100

Property Value        500000    
Duty                  17765     =VLOOKUP(C9,A:C,3,TRUE) + (C9-VLOOKUP(C9,A:C,1,TRUE))*VLOOKUP(C9,A:C,2,TRUE)/100

Download the Excel WorkBook.

Update, next day
This also works for Individual income tax rates;

Tax Rates            
Cutoff [$]  Rate [%] Tax [$]  Formula
0           0        0        0
6000        15       0        =C3+(A4-A3)*B3/100
37000       30       4650     =C4+(A5-A4)*B4/100
80000       37       17550    =C5+(A6-A5)*B5/100
180000      45       54550    =C6+(A7-A6)*B6/100
Income               100000    
Tax                  24950    =VLOOKUP(C9,A:C,3,TRUE) + (C9-VLOOKUP(C9,A:C,1,TRUE))*VLOOKUP(C9,A:C,2,TRUE)/100