Don't beleive it. I thought it was the world of high speed multichannel computing. The perfect place to wire the neurons of my chaotic multichannel mind into. A cosmos of thoughts and firing on all channels, or at least as many channels as my eyes, and fingers jumping across the computer keyboard will allow. Seems I'm backward I don't have a mobile phone. But what use is one. As far as I know I cannot use AutoCAD on it, nor MultiFrame, possibly use Excel but that sounds painful. Even when in office, not heavy into answering phone, usually want to hit it with a sledgehammer. All the faxes are junk advertising bar one, everyone, bar one now emails rather than fax, and a large number of phone calls are telco's wanting us to change providers. Suppliers have become providers.
As for clients well I understand that they have an urgency to get their structure designed. Sorry, not designed but assess their existing construction. The urgency wouldn't exist if they designed and got approval before it was built. Problem is we cannot design in a reasonable timeframe either, because constant interruptions with more and more people who want to push to front of queue with an even greater urgency, to avoid demolition. Where is our actual regulation? What is the point of asking people to apply for development approval after they have built something already?
Further more there is something wrong. It seems people do not apply for development approval because they perceive that it takes too long. There are a few who perceive that it is their property any how, and therefore why should they get approval. These tend to be the people who don't get the idea, we really do mean 12 weeks: so don't phone everyday to see where the calculations are. It just delays our ability to get on with anything. Further more these tend to be people who don't want to pay. It is these few people who cause us to put the answering machine on and screen calls, and only talk to regular clients. Furthermore the work is not really valued, just some rubbish to satisfy council, therefore cannot afford to employ anyone to deal with inflow of enquires. {These people also the ones first to complain you didn't comply with regulations and responsible flooding of their property.}
But they are right calc's-for-council are rubbish and low value. The value of engineering lies in design, before materials and labour are wasted on construction. Now calculation effort does not change with the size of a structure. Effort varies with structural form. So the effort to design a 3m beam is the same as a 25m beam. The effort for a carport the same as the effort for a sports stadium, if employ same structural form. That 12m is probably longest span from a single piece of steel, means that structural form gets increasingly complex as the size of structure increases. But within certain size ranges the calculation effort remains the same: thus there is a stepwise increase in effort from one size range to the next. (so much for my continuous spectrum theory in previous post)
Consequently for small scale structures it is preferable that they are pre-engineered and manufactured many times without variation. It therefore should be more economical to purchase a carport or verandah from one of the specialist builders (few if any can design, they rely on consultants after council requested further information: and given 3 months to respond. My response of 12 weeks is a semi-polite way of saying go away.).
If something is pre-engineered and manufactured then the cost of engineering can be distributed across the sales of many items. For example $1 billion's for GMH's model commodore most likley is expected to be recovered over 5 years on sales of several thousand. Typical carport and verandah builder appears to sell around 40 to 50 such canopies per month, of all shapes and configuations many potentially outside the scope of the standard calcs-for-council that they hold. The result is that going to one of these specialist pergola/carport builders can result in unwarranted delays. But apparently it is too expensive for them to employ technical personnel on staff. I say technical, because a canopy doesn't require an engineer to design the structure, and the SA regulations do not require. The engineer is only required for the independent technical check to grant the final approval. A 2 year qualified engineering associate with structural design experience should suffice.
Now one of the points of going to a specialist canopy supplier, is the expectation that their product is pre-engineered and they have ironed all the problems out. For example strengthening of your house before attaching the canopy to it. You are not expecting problems. Place order, get approval and get it built. It shouldn't take too long from start to finish. This assuming adequate supply of all the resources. The two critical resource shortages are the skilled carpenters/builders and structural designers. This results in delays.
But there is another issue: the number of owner-builders or is it the price of the commercial canopies? Many people check the cost of materials and then determine that they can build themselves cheaper than they buy from one of the commercial suppliers. So what is going on? The average person wouldn't consider cost of materials for a car or videorecorder and decide they can make for themselves cheaper. So why do they do so for structures? Not just verandahs, factories, offices, warehouses, health centres. Many business owners choose to be owner builder, and yet they are not qualified for such task.
Housing in particular is strange. Builders indicate too complex and therefore expensive to build. So what do the owners do? Find the best builder in the trade, who as the skills to tackle the project? No! They decide to build the complex house themselves. Crazy!
Back to the canopies. It seems that the specialist canopy builders (specialist as in they don't typically build houses or other structures), have not developed reputations for competence, quality service, and reliable supply. They have however developed a reputation for extortionate prices.
I am not sure if this is a valid reputation. But for a few I have done the structural calculations for, I have seen the sales price, typically I don't get to see such things. Just costing timber at retail prices, the price of supply is many times that of the material (2 to 5 times). And apparently they cannot afford cost of engineering because only won job by $50, what ever that means. Many of the suppliers don't have offices, workshops or display centres, nor any real staff. They are builders, their office is their: car and mobile phone. All personnel are subcontactor builders. So basically they have low overheads. Then there are those with offices, showrooms and workshops, and sale staff, but no technical staff. Employing trades seems to be a problem for they have a high tendency to quit and set up in competition to grab a greater share of the profit.
The purpose of business is to maximise profit not minimise costs. The simplest way to increase profit is to keep increasing unit sales price until the drop in sales volume produces net drop in profit. Supposedly then should have found the intrinsc value of the product. For the most part, the greater portion of this profit is not for personal luxury, but the expansion of the supply capability. If the collective (employees) who contribute to generating such income perceive inequity, they have potential to quit and setup their own business to gain greater share of the percieved profits themselves. Expanding production capacity requires bigger workshops or more workshops distributed to local areas. So way income of small business is distributed is important. But so also is geographical distribution of business. If not reaching a geographical area, then may loose that area to another supplier, at the same time as market in current area dries up. The result is cease to be in business. Any how many parameters to consider and gets complex.
The track here was buy or build? And something is wrong with the industry if the choice becomes build. Sure there may be a certain pleasure in building something yourself, but I am not certain that is the dominant reason, especially not for business owners, it may be the case for home owners. As far as I can tell, the prime reasons are high supply prices and low quality service.
The price of the manufactured structures is not seen to be the intrinsic value of the product, and owners they can do just aswell as a builder supervising the supply of subcontractors and making themselves. What does the word build mean? From the Builders Work Contractors Act, the focus is supervision of trades, not actually having a trade. Though the focus for the adminstration of licensing is the trade skills, not the skill set defined in the Act. Training for a trade doesn't actually provide the appropriate knowledge base to achieve the AQF competences defined in the act. Hence not surprising that licensed builders are typically seen as charging extortionate fees for their services. They do not have adequate breadth of skill, nor depth of skill in the required areas of practice. Therefore the public does percieve that they can do the job just aswell.
The big problem however, is that many of the specialist trade subcontractors are locked into main building contractors. {Crazy concept: all are contractors, only become subbie relative to a given contract}. Hence, owner builders can have significant timing problems getting the trades when they need them, for they are secondary to more regular client of principal builder. Thus greatest opportunity for D.I.Y for owner builder is those trades where no trade license required, but may require a licensed or registered individual to inspect, witness and approve before further progress can be made. Nailing some timbers together to build a canopy is one such possible area.
However a freestanding canopy is simpler than an attached canopy. An attached canopy requires a critical assessment of the house that the canopy will be attached to, and it may turn out to be impractical to strengthen the house. This does not mean cannot build a suitable canopy, it just means it requires more structural design to come up with something suitable. For example something with a cantilevered roof structure.
The issue is checking out the possibilities. Not deciding want to build it this way, everyone is being unreasonable, and going ahead and building it your way anyway: then expecting someone can proove it is structrually adequate as defined by the buidling code. Those possibilities will typically not be checked out by the pergola builders: for one: most don't know what a real pergola is.
Where was I heading??? Materials cost subtracted from commercial price leaves a massive difference. Therefore decide to supply own labour, but need more than one person. Typically two people one to help with material handling. Most of time they are just keeping you company, and compensation is owe them a favour, a good feed at a bar-b-que, so many cartoons of beer, or whatever work out with mates.
Such could be considered as saying don't want to pay for training of apprentices. But if get development approval have to pay construction training levy any case. Can also consider cost is own wage rate multiplied by time expect to take. Then re-assess if really is an extortionate cost the commercial enterprise charges. Task not worth your wage rate then lower to what think it is worth: check industrial awards. Check stats are people being paid over award rates in the industry. Is the price really extortionate?
Being determined to go ahead anyway. The next issue is timing. You have to get development approval, could take anything from 2 days to 12 weeks: if all is going well and don't need engineering input.
The need for engineering input is simple to assess. Is there a national, state or industry association which publishes pre-engineered solutions for what you want to build. For example the timber development association (TDA) publishes a construction guide for carports, pergolas and verandahs. The next step is does what I want to build comply with this guide. For example TDA guide has maximum span of 4.2m, even the commercial builders pay no attention to this, seemingly hoping council will miss the point. Though many of the builders don't even spend the $30 or so it costs for the guide. They have never read it. They just go of past practice, they were building big for past employer so obviously can get approval. May be so, but they don't have the documentation to get such approval. They will also tend to charge the full cost of the caluclations but get them as generic and use on many future projects. The engineers may put project title on to make them project specific, but it has been known for the builders to use liquid paper and remove the house address used as project title. Some times this gets picked up or causes further delay. But it is unknown how many times council does not pick such occurrences. Anyway the point is the builders cannot provide proper design service, rely on consulting engineers, and typically supply poor quality drawings of proposal to the consultants. The relationship between consultants and such builders is strained, and the project is typically placed in a queue and given low priority. Thus introducing further delays to the project.
The issue is if the builders think design and engineering is about producing some rubbish documents to keep council happy. If they employed engineering associates on staff then they could design their product, and have pre-engineered solutions prepared before the customer turns up. More to the point such pre-engineered solutions would be advertising medium attracting the customer: not a fancy photograph of what some one else has built. If the customers request is outside the available pre-engineered solutions then the engineering associate can carry out the custom design. But more importantly they will then also be aware of developing needs in the market and can adapt and develop the range of pre-engineered soltions available. The wages of the engineering associate may be an on going operating cost, but they are constantly adding value to the goods and service available.
The buyers are not seeing this added value and choosing to build themselves. But they need pre-engineered solutions and few are available. That causes delays. For there are many people and few engineers and even fewer engineering associates providing structural design services. In simplest terms really need to seek design and engineering services some 12 months before start building. For many people this is not an issue, for the 12 months wait to get calculations provides 12 months to save money for materials and development approval fees and engineering fees. I am not saying it takes 12 months to do the calculations, but that cannot be certain of just how many people are seeking such services at the same time. If simple and low demand could get report in as little as 48 hours, if complex a week or so. But if demand is high, then there is a long waiting queue. Much the same as the internet gets clogged up, and just like a traffic jamb, the pipeline through the available service providers backup and long waiting lines result. Except you cannot see the waiting line like you can in the shopping centre or bank. And it is much more difficult to train a structural designer, to provide more service lines.
So building yourself may save money. But it may take longer. Sure you can get materials and start building on weekend, and probably get built in 2 days, but getting approval is dependent on availability of engineering, and that is going to generate a long delay if no pre-engineered solutions available.
And it should be noted you cannot use a manufacturers pre-engineered tables for your own building. For example you cannot use Lysaght carport tables and buy materials from say Fielders, or worst buy imported steel. For c-sections have no national standard, so not all of Fielders sections can be used as a substitution for Lysaght, for they have different dimensions (such as smaller flanges, the critical dimension): though it maybe well be common practice. Whilst imported materials, may have different strength for example steel yield strength 280MPa versus Australia's typical 450MPa, as well as different dimensions for the section profile, and the quality of the galvanising can also vary.
The other issue is fairness. The manufacturers have paid for the design and engineering. They need to recover such costs, and it is unreasonable of council to grant approval to one builder based on another builders technical data. Likewise for the owner builder. So in terms of the approval process need to be committed to a specific manufacturer or approved equivalent. But can only really refer to "approved equivalent" with respect to materials not the over all structure. Then need some one to make the engineering assessment and approve the substitute materials. So basically if use a manufacturers design brochure have to use their materials. This may not be a problem since still only paying for the cost of materials. No plan, no material take-off by the supplier. You draw up the proposal and determine quantity of materials required.
And as I said drawings by suppliers are typically poor, consequently their material take-off can also be inaccurate. Some suppliers won't supply what they see as extra. So if buying it is still helpful to get independent workshop quality drawings produced to make sure correct quantity of materials are supplied. And check the contract to be certain of what is being supplied and paid for. Like if they haven't produced accurate drawings, then cost is not based on accurate material count, therefore cost of missing materials is not extra to the contract price. The price is for the building, if it cannot be built then they have failed to supply: they need to provide all materials and with no extra cost. Similar arguments can occur when they come asking for fees for so called additional engineering. Is it truly additional or does contract already cover by wording of contract?
Any case assuming owner builder you have to produce the drawings and account for members, all connections and all the brackets and fasteners required. A builder shouldn't have to stop part way through construction and go get extra materials for extra members, nor extra brackets and fasteners for connections. They should have worked the member count accurately and they should have plenty of brackets and fasteners in reserve: just incase they drop and damage some during handling. Though it seems a lot of the canopy builders cannot get the material take-off correct.
If the drawings identify all members and describe all connections then the structure can be assessed for adequacy. If not all the members are identified, then structure is probably unstable, and should not be granted approval. No tables of strengths or spans required for such exercise. Similarly checking all members have a suitable connection described does not require any tables of connection resistance. Once the structure is fully constructed on paper, then can move into assessing strength and serviceability. Serviceability primarily concerns stiffness and how far the structure and its elements deflect, stretch or otherwise deform under load. There is no codified requirement for such deflections it is largely a matter of subjective or personal judgement. So typically only checks on structural strength are required, and appropriate deflection limits to avoid instability which will lead to loss of strength.
This where the structural designer (engineer, or engineering associate) may or may not be required. It just all depends on how suitable the available pre-engineered solutions are and how igenious the individual is at adapting them to suit their purposes. In general for example the timber framing code AS1684.2 is not suitable for a pitched roof carport or verandah, if want with out the ceiling joists. This will therefore lead to design using the timber structures code AS1720, and change from an exercise taking a few minutes to an exercise taking a few hours. A few minutes of suitable software available. Which is a problem engineers don;t typically design timber, most can be done from the timber framing code. So more software available to AS1684.2 than there is to AS1720, so chances are the calculations will be by hand, unless they have say Excel workbooks available to AS1720. An Excel workbook for timber design is not the same as a workbook for canopy design. Whilst a workbook for canopy design maybe otherwise locked into a specific material. So the specific clients canopy likely to be a time consuming exercise, for the consultant who only deals with canopies on the rare occasion, and much larger structures on a regular basis: eg. multistory buildings. Sorry! Its not the size but complexity that accounts as I indicated earlier. Actually the shapes of some residential canopies makes them more complex than simple industrial buildings. Which is the problem: constructing it may be simple, 2 days work. But proving mathematically that it is stable and strong enough for its intended purpose could take signifcantly longer than 2 days even with computer software. The consultants will use general purpose structural software. The builders if they have software will use specialised software for design of their canopies. Most is relatively simple and the users are not all that capable of putting a full proposal through such software and assessing it fully. That is they may be able to assess individual rectangular chunks of the canopy, but not the interaction between those chunks. Such issue may then cause a delay at council, and then further delays as engineering is sought.
Basically being an owner builder is not simple. But going through specialists isn't necessarily going to make it any easier. Even if plan to go through plan drafter and engineer, then going to experience problems, due to demands on time and scarcity of resources, and low importance of residential canopies to consultants. The canopies are low importance because they only turn up in the office occassionally, when there is a problem.
If can split the plan into more than one rectangular area, then problems are likely to result.
Anycase the starting point is to construct the canopy in as much detail as possible on paper. Think of the drawing in those terms of building a prototype. The objective is to check if it can be built, and determine what is needed to build it. Not just the materials for construction, but also additional materials and equipment which may be needed to assist with the actual construction process. This is the real activity of design, not crunching numbers for stress and strain. And someone needs to carry out this design.
The person building really needs to produce the drawings and think about how they are going to fabricate, handle and place each and every component. If someone else as produced the drawings then the builder really needs to produce additional drawings, staged construction drawings. This they can do by simply tracing over existing drawings with highlighters. However such doesn't check if the dimensions and geometry on the drawing are valid. many changes by the client during design, may result in drawings saying one thing and showing something else. Also there may not be adequate dimensional and geometric information on the approval documents: therefore copy drafting will provide a check. Because if cannot copy the drawing by reading it, cannot build it. Should not scale any dimensions of the drawing, only use dimensions written.
Anycase more can be said and more clearly. This is just a rough collection of thoughts, freewriting in a public forum. That is to write 5000 concise words on a topic need to write a draft of 20,000 or so, and refine them. This is part of that draft.
The idea is to try and put the design process in a public forum. So that the complex array and chaos of characteristics which need to be assessed to reach a valid and acceptable design can be seen.
I also have a general view that: near enough makes a start whilst perfection aborts existence.
This is a blog and it forms a timeline. So what I say may get repeated, but its organisation and its context may change. The more orderly stuff will be eventually found on my website, which I will provide at a later date. Though it can be found in earlier blogs.
Speaking of early. What I am doing writing at this time? Thought doesn't sleep. So why lie awake thinking when I can write thoughts down? That is the new challenge. Thus far never been able to get writing with a computer. Wake up pick pencil up and write on paper. Get buried in paper: essays no one has read. Get up switch desktop on, the thoughts have gone before computer starts up. Attempt go back to sleep and brain churning again. Therefore the writing medium cannot introduce a delay. There is also need for continuity of thought. Typically I am always studying to solve problems displaced from real interests And other peoples problems put me on alternative paths of knowledge discovery. Which has its benefits.
No innovation was discovered by chance. All were discovered by people looking for solutions, they just weren't consciously looking for the solution when they tripped over it. That is if they weren't looking for a solution then they wouldn't have recognised the completely lateral discovery when they happened upon it.
Being displaced from my primary interests means I have divergent views when I get back to them, and also divergent views for that which I do daily. For example I don't perceive building structures from the same perspective as others. I don't actually like buildings, and oppose construction of cities and tying people to one place: something undemocratic about it. Not quite true, I have specific requirements for the design of a city, I am just increasingly in favour of increased mobility. I was born in the space age, I was expecting cities on the ocean floor, the surface of the moon, and space stations beyond Pluto, by now.
Just as that small island off the coast of EuroAsia became the stepping stone to the world. So too is the Earth a stepping stone to the universe. I don't expect the species will stay on Earth, but life in space is going to be radically different, and whole different ethics and perspectives. There can be no naval type burials in space, no biomass can be lost from the space ship. The space ship will be a higher form of life, if it looses biomass then it will die. The human occupants will be little more to the space ship than blood cells are to us. Similarly a city is a higher form of life, a plant, lacking mobility and all the disadvantages of a plant, and no benefits of an animal. Nones the less humans are little more than blood cells to the city and many are expendable.
There is thus a conflict between the simple rural life, and the benefits that a city can bring. But the ultimate destination is most likely that multistory apartment transposed to room on an ocean going ship and then a space ship. There won't be any vegetated earth to visit, it will have been fried by the dying sun, and we probably need to be far removed from it. But what kind of life will it be?
However until we reach the ultimate destination we had better look after the planet we have. Most especially if do not want the only jungle on planet can see if the concrete jungle of the city. What we have is transient and we need to look after it.
So writing on a computer in the early hours of the morning is not helping.
No comments:
Post a Comment