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Soil and site tests and surveys

You often see prices for new homes advertised by builders. In truth, it is simply not possible to calculate a price for your new home until many tests have been undertaken. Your new home is very “individual” and needs to be treated that way.
To calculate an accurate price, and to build the house ‘properly’ will require the following due diligence.


Never trust a subdivisional soil test. Soil varies over the block, let alone the whole subdivision. What is required is a full soil test taken in several spots over the building area. This will evaluate the reactivity of the soil, and any fill that has been exported onto the site and the depth of the fill. Done correctly, this soil will then be taken to a laboratory to be shrink and swell tested. A report will then be prepared classifying the soils reactivity, KPA rating (ability to hold the house weight) and other details, including tree locations – as special consideration is required for larger trees that are going to be retained on the property which are close to the house.


A Surveyor will take levels on the site. These levels will be entered into a program which will show the volume of soil that will need to be imported or exported from the site and also the height and length of deep edged beams and retaining walls.


This is one of the most critical aspects in building a new home… and one that is very often not done. Armed with the full site assessment from these tests, it is then necessary to work out the ‘best practice’ or correct way to build the home. This will involve the slab design, piering, tree piers, finished floor level, recommended cut and fill, requirement for deep edge beams and retaining walls. The structural engineer will then design, draft and engineering all these details.


Much of what is described above is not done by MOST builders. Many builders rely on a sub-divisional soil test, do not do KPA ratings or shrink and swell testing. They then make their own assessment of the site and do a floor and foundation design accordingly. This is allowable in the industry and meets the minimum standards. The issue with this is that builders will allow the least possible in order to win a job and will often need to vary the price once they get on site and learn the full site requirements. At that point its too late to turn back, and they are within their rights to charge extra if work is required that exceeds their allowances.


At Bellriver we are only interested in building your home the best and right way, no necessarily cutting corners to trim costs. To this end, we do full site due diligence, including all the tests mentioned here + a series of tests to check for rock. This is important, as our fixed price tender is fixed… even if we hit rock. We then get an external structural engineer to fully assess the tests and design and engineer your new home accordingly. It’s the only ‘right’ way, and the only way we build.
As a service for our clients, we normally do this first, prior to you making any commitment. For a small fee (which we subsidise), we will order all these tests, and provide you with a full written obligation free quote. That way you know EXACTLY what is required before you pay a deposit on your new home.


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