Sub-Soil Drainage

What is Sub-soil drainage?

Put simply it’s a drainage system for stormwater in the ground.

Many sites in Australia have a clay based soil making drainage after a heavy rain near on inpossible. Some lucky people have sandy sites where any rain quickly seeps into the soil and disappears. These folks rarely have to worry about when a heavy storm hits. The worst that happens is their soakwells fill up and the water over flows and spreads to the lawn.

This can be seen here in a video clip I took of the Perth storm of March 2010. We were quite lucky and didn’t suffer any hailstone damage, but many are still getting over the damage left behind.

Those who live on a clay site know that the rain water doesn’t go away. It leaves lots of puddles for the kids to get muddy in for weeks to come.

In some new areas the developers have taken this in to consideration when preparing the block.

Below is what sub-soil drainage looks like.

The site has been excavated and the drain laid. The idea is that the rain will seep through the top layer of soil and when it hits the clay it will flow into the drain and off to the nearest lake or park.

Speaking of parks being used for stormwater check these out…

This is a sale plan for some new development.

Here is what the site looks like during development in winter

This is the built park in March (end of summer) mostly dry...

And July (end of winter) soil saturated

It’s not that subsoil drainage is bad. It is really a good thing. The thing to watch out for, is if the subsoil drain falls within your property. There are requirements for how far away from it you can build. What you bought thinking was a 20metre wide block could turn out to be 17metres of actual buildable space, even though you’ve found the best house design for a block 20m wide and paid the full price for the land, you can’t actually build on it all.

Sustainable living

I think in Australia we are behind in doing our bit to save the planet. We have only just brought out the 6 star minimum energy rating for new homes in WA.

While some builders can achieve 9 star ratings the construction of these homes is out of reach, price wise, for the majority of people. Until alternative products are more readily available at competitive prices and the regulations allow new materials and design solutions we will remain behind the rest of the world.

OK so you’re building and want to do your bit for the environment. The easiest way you can reach the 6 Star requirements is to have your living areas (lounge, family, theatre, games room) face north. Provide larger windows to the north and eaves all the way around your home… easy! You’re designer should already be helping guide you down this path already.

What if you’ve already built or purchased an existing home and it doesn’t look like reaching a 6 star rating? Well the good news is you do have other options which will boost the energy efficiency of your home.

This might be an excessive way of achieving a good energy rating...

Don’t lose hope though. There are companies out there who specialise in helping you get the 6 star rating you need.

Here are some resources to help you:

Contact your State / Territory government or local council for further information on building sustainability and energy efficiency, including what rebates are available. www.gov.au

A set by step guide to buying your new home: http://www.yourhome.gov.au/

Beware if it’s cheap!

You just bought your dream block for a great price... saved thousands of dollars on it. All that money saved can go on a bigger and better house right?... wrong!

There’s no such thing as a cheap block. What you might have saved on the ticket price for the land you will almost certainly have to spend elsewhere getting up to a standard you can build on.

It could be a 1200m² block, you’re thinking of subdividing, but find out after you’ve bought it that the block is too steep, retaining walls would cost around $70,000 and the local council have placed restrictions on it. The restrictions prevent you from even building a regular home and are asking for the external walls to be 32c instead of the regular 25c, eaves to be wider than normal and an undesired verandah which has to be half the width of the of the front of the house. Not to mention your house now has a steep winding driveway and takes 30mins in what feels like driving up Col De Turini Mountain. Your cheap block now not so cheap.

Col De Turini

You could opt to buy a massive block near the coast with huge potential and room even for a horse!

Then find out the local council has an odour problem and are preventing you from building on 70-80% of your block... what a bargain! You have an odd shaped home but a lovely big back yard. Don’t forget to leave some spare pegs by the back door for when you leave the home.

Here’s another really cheap block you could buy. This once big block has been subdivided into 3 smaller blocks saving you the cost of upkeep on a big block. All the work has been done and the block is flat! What could possibly be wrong with it?

Well the retaining certainly gives you an elevated view of the lake, and the neighbours won’t block your view.

So, why so cheap?

See that shadow? That is the shadow of a 2.1m high retaining wall. Yes to the front of your garden.

Views? Yes
Access? No

So please do your homework before buying a block of land.

If the land is cheap find out why. Do your sums.

Cheap isn’t cheap!

Introduction

Hello and welcome.

This is my first post of what I hope will become a useful resource tool, for anyone thinking about building their own home, either through a builder or as an owner builder.

I have been involved in the building industry for several years and love the daily challenges. The biggest reward I get is from passing on a little bit of knowledge to others and seeing it help them achieve their happiness in building their own home.
 
A lot of my knowledge comes from having worked in local council as a Building Surveyor and more recently managing a compliance team for a project builder, as well as running a private building surveying company.
 
I hope to share my thoughts, ideas, frustrations and inspirations.
 
So sit back and enjoy the ride.