Advanced Structural
Designs ACN 097 789 87
91 Banambila St ARANDA
2614 Telephone
61612171
Facsimile 61612170 Email mal@structuraldesigns.com.au
What is the most economic structural framing system for three storey walk-ups?
Some engineers will tell you that they have looked at all of the options and have the most cost effective structural solution all worked out for this form of construction. These are generally the same engineers who spend too long looking up estimating guides and not long enough talking to the developer and architect, looking at the development proposal and the evaluating the site.
One very basic consideration is how long the developer wants to hold on to the units, as maintenance costs or consumer risks (eg termites) can be a factor in determining investment returns. Another factor might be what internal finishes are required and how these can be most simply achieved.
Before deciding on a structural system we need to have some idea of the following
Are load transfers required, on which
floors and are they really necessary?
Are there any height restrictions for
the site and what are they?
What are the likely site foundation
conditions? We can normally obtain a
rough answer at no cost.
What is the standard of finish
required and how durable/repairable should it be?
What is the typical aspect ratio
(height/width) of the building?
How well thought out are the service
risers and where are services in the ceilings?
Can this be rationalised?
Is there any perceived value in
exceeding BCA noise requirements at marginal cost increases, or in obtaining a
more reliable STC outcome?
Is there any perceived value in
minimising wall thicknesses to give more net floor area?
What is the preferred ceiling height
and where can it be compromised?
Can we avoid running light switches
and power outlets in primary support walls?
What are the financial benefits of
shortening construction times?
Is the construction to be
staged?
Is crane access an issue on the site
and what is the maximum economic reach with each construction system?
If a builder is already on board what
are their preferences and what experience do their staff have?
Where is the building industry heading
and will site labour be in high demand at the time of construction?
From our perspective it is pointless to decide on a framing system until most of these issues are addressed. Often the biggest savings we can make for a developer are achieved through consulting on the building during the preliminary design to ensure that load transfers are minimised wherever they occur and that structural systems are considered from the outset. We often give this preliminary advice free of charge on the understanding that if the project proceeds past DA we will be engaged to carry out the structural design and documentation for an agreed fee. In many cases the savings from such preliminary advice will exceed our total fee for design and documentation.
Some particular forms of construction such as precast and tilt-up are rarely successful unless designed from the outset with the particular construction technique in mind, while others are amenable to almost any geometry.
If you need some assistance with preliminary design or just need a competitive quote from a structural engineer in Canberra ACT or the surrounding region who has done it all before call Mal Wilson from Advanced Structural Designs on Ph (02) 61612171.