In any typical month, Partridge receives somewhere between two and five phone calls from homeowners who are concerned about major structural cracks in the walls of their house. Sometimes these have “suddenly” appeared; other times they’ve been present for a while but worsened more recently.
Real estate and house prices make for challenging times. For home owners with growing families or changing circumstances who want to upsize their house, the prospect of selling up and then purchasing a bigger property isn’t exactly appealing, particularly noting the costs associated with stamp duty and the inconveniences of moving.
Ask an architect what the differences are between the type of house they design and a standard project home offered by the volume builders, and they’ll give you a long (and worthwhile) list. Apart from the obvious factors and advantages of a bespoke design that is custom-tailored to the client’s needs, they might also cite the more efficient use of space and circulation; the attention to solar aspect and natural ventilation; the focus on insulation and colours; the attention to detail; and the vastly superior quality of the finishes, fittings, and overall aesthetic. Not to mention the fact that the custom builder who builds the architecturally-designed house will undertake and complete the construction in a very different manner to the volume builder that supplies the turnkey project home.
So you’ve got two fee quotes from two different engineering firms, and you have to decide which one to appoint. Now what??
Just so we’re clear on the intended readership and our objective here, let’s state from the outset that what follows has been written chiefly for (i) architects or project managers who procure fee proposals and quotes from structural engineers on behalf of their clients, and (ii) home owners embarking on their residential building project – either an all-new house or an “alterations and additions” renovation.
If you’re an architect managing a client’s residential project or a homeowner undertaking an extension to your property, chances are you’re going to need a geotechnical report. If you’re excavating into a sloping site, or putting in a new swimming pool, or digging out a new basement level for your house, your structural engineer (that’s us!) is definitely going to need a geotechnical report. The purpose of this article is to outline why and when you’ll need a report; how you and your consultants (plus your builder) can benefit from it; and what to look for. Some of the descriptions and examples we’ll discuss below reference the suburbs and geography of Sydney, but the principles are the same Australia-wide.
Most of the articles we write and publish on the Partridge blog are written with the intended audience being architects, builders, and homeowners who might be contemplating renovating or building a new house. This one’s probably aimed more at engineers, although – if you’re an architect or builder – what follows might give you some insight into how engineers think and how we can better serve you.
“Art without engineering is dreaming; engineering without art is calculating.” Steven Roberts
For most people viewing artwork – and particularly in the case of sculptures – the joy is in appreciating the artists’ work, endeavours, interpretation, and skill. But have you ever considered that, sometimes, the piece of art might have some engineering behind it?
Until very recently, it was extremely common for us here at Partridge to have no knowledge or involvement with a project until after it came out of Council with its DA approved.
For 95% of our projects, the architects would independently develop the DA-submission plans with their client, lodge the DA, and then contact us a few months later to sign us up for the job after the DA was approved.
Only then, once all floor levels, structural zones, and building heights had been approved and “locked in” with Council, would we as engineers then have the opportunity to analyse the structural loadpath of the building and determine the size and thickness of its structural elements. For example, we’d begin to explore the thickness of the suspended slabs; the depth of the floor joists or roof rafters; and the size of the beams that would span across large openings and support the structure above.
“What are we building here, mate – the Sydney Harbour Bridge???”
It’s the most common question asked of every engineer when he or she gets to site. The moment the steel fixer believes the slab has too much reinforcement, or the fabricator thinks all the steel beams are bigger than they’re supposed to be, the engineer is instantly accused of designing the Harbour Bridge all over again!
Stereotypes aren’t always appropriate or deserved, but the general stereotype levelled against engineers is that we’re all a conservative bunch who over-design everything. Being over-conservative with our designs or using overly-conservative factors of safety, the presumption is that engineers are risk-averse and too busy covering their backsides than designing efficient structures.
Is there any truth in this? Is the criticism warranted, or is there a bigger picture at play here?
If you’re planning a reasonable renovation to your home that involves changes to your roof or the lawns/pavements surrounding your house, there’s a good chance you’ll encounter the words onsite detention. No, it’s not some form of Council imprisonment! It’s just a clever way to deal with all the water that falls on your property when it rains. Let’s explore…