A Simplified Explanation Of Site & Earth Works Part 1

What are site works or – earth works? 

Site & earth works, can be anything required before commencing construction of a new home.  They generally don’t form part of the structure itself.

The type of things that may be included in site & earth works for Perth lots are:

Re-peg of the site

A repeg confirms the location of the boundary positions. It’s critical to ensure the home is set out in the correct position on the lot. It’s even more critical if the home is being built on one or more boundaries.


Earthworks can include all or any of the following

  • Scraping and removing overburden – vegetation
  • Turn over the soil to remove debris.
  • Cut and fill the site to the average level.
  • Possibly import sand fill if required.
  • Compact and arrange a compaction certificate.

Preliminary site – earth works on a sloped rear strata, small and difficult block – Karrinyup – 2408

Service runs

Bringing the power, water, communications, gas and any other site specific service from the supply location to the connection point in the home. Often this requires a great deal of coordination especially if on a rear strata lot as all services are generally in the same trench.


More often, piling is required under some of the home footings to allow the home to be built near a sewer main or other type of easements. Usually this would be completed using steel ‘screw’ piles that finish inside the footing they are supporting.

Storm water disposal

Almost all local authorities now want suitable storm water disposal systems in place as part of the building permit conditions, This could be concrete tanks or the more recent polypropylene modular systems.

Removal of excess soil

The digging of footings, installation of house drains and storm water disposal systems generates a remarkable amount of excess soil. Quite often up to 20 cubic metres that needs to be removed and dumped somewhere as it cannot stay on site.

Limestone access track

In Perth’s often sandy sites, and especially when building at the rear of an existing home (rear strata or battle-axe lot) its necessary to have an access track. A limestone access track makes it easier for trucks to drive on the lot to make deliveries. Generally it requires approximately 100mm of crushed limestone covering the access track to allow trades and suppliers to get their vehicles near the building site.


In cases where there is too much slope on a lot to allow simple cut and fill earthworks, retaining of some sort will be required. This can be a

  • simple brick build up so the footings and brickwork are just built down to accommodate the slope
  • or it could be a retaining wall.

Retaining walls can be built out of double brick, concrete post and rail or limestone blocks, depending on where the wall is to be placed and how high it needs to be.

In addition, there could be other things like removal of existing fencing, removal of asbestos, temporary fencing, hard digging and traffic management to name a few.

Brick build up on a sloped rear strata, small & difficult block Karrinyup – 2408


The cost of site works can be intimidating which is why its important to deal with a builder who knows how to assess the site correctly. With Central Avenue Homes, from the outset, those costs are taken into account when designing your home to your budget, so that there are no nasty surprises.

For a more specific idea of what your blocks Site works will include contact us at Central Avenue Homes.

Site – Earth Works Costs Explained

We include all itemised costs for works related to the unique nature of your site once we receive the Survey and Engineer’s reports.

  • Earthworks,
  • Retaining,
  • Piling,
  • Service connections,
  • Crossovers,
  • Storm water,
  • Clay or Engineers details,
  • Fence removal,
  • Temporary fencing,
  • Hard digging,
  • Work-safe requirements,
  • Traffic management
  • Access track, etc

All builders will  need to do the same amount of work to satisfy Shire and Engineer’s requirements, and will charge for all of these works somewhere.

Comparing Site costs

When comparing site costs with other builders, clients should find out exactly what is included in their quote.  Then compare those costs with our costs. Ask the other builders when and where they will charge for those items not included in their estimates or quotes.

Owner site – earth works quotes

Sometimes clients will get their own quotes for earthworks, and other works with complex or clay sites. They will remove these costs from the contract, because their quotes are cheaper than ours.

Unfortunately, in many cases the reason these quotes are cheaper is the works are not to Shire or Engineer’s requirements.

The saving they thought they were making in reality will cost them much more.

 No Surprises or additional unknown costs

With Central Avenue Homes completing these works, you will be guaranteed they’ll be:

  • Completed to Shire and Engineer requirements.
  • All costs provided upfront.
  • No unexpected or unknown costs.
  • Will be supervised by us as part of the building process.

For a more specific idea of what your blocks Site works will include contact us at Central Avenue Homes. Phone 9456 3366 or email [email protected]

Posted by Lee Grainger

For more insights into site-earthworks explanation, check out our other blog posts in this series:-

A simplified explanation of site – earthworks Part 2

A simplified explanation of site – earthworks Part 3

A simplified explanation of site – earthworks Part 4