Tackling the question of cost before starting a project is always a challenge. There can be a lot involved, yet, it is pretty important. So, we will take a look at the process of estimating cost prior to starting a project. In this article, to illustrate, we will use the example of cost to build a trailer.
This article comes from many customer questions like “How do I estimate the cost to build a trailer from your plans?” The topic is so important that we have an FAQ about it. Also, a similar article with a focus to save money – “How Much Will It Cost?” However, this article will focus on how to get an estimate before you start building.
What Do We Need?
The only way I know to estimate the potential cost to build a trailer is to get a bunch of quotes. Start with buying the plans (how else will you know what to estimate?) Use the plans and Bill of Materials to create a list of the things you will need.
A Bill of Materials (often shortened as “BOM”) is a list of the things to build the product. Things like components to purchase, and raw materials are on the list. It can be simple or detailed, in a table, or just a list. Usually things organize by assembly order, alphabetically, or by material type (like in our plans).
In the Mechanical Elements trailer plans, we list components to purchase. (Things like the axles, wheels, tires, jack, lights, wires, pins, etc..) These are all things that contribute to the cost to build a trailer.
Next, the plans include a list of raw materials (like steel beams) that you must fabricate into the trailer. Finally, a list of material for various options (like different deck types). Each item has some explanation as well as information about the options or recommendations for the item.
So, the first step is to make 2 (maybe 3) lists:
- One for the COMPONENTS to buy that meet your chosen design options.
- Then, a Second list of RAW MATERIALS to buy. It can also be helpful to divide those lists into groups by vendor. For instance, you will probably buy raw steel beams from a different place than wood decking (if you need wood). Axles may come from one source, but trailer tires from another.
- A Third list – for some trailers – will include parts for someone to make for you. Things like parts to have cutout by waterjet or laser. Or parts that require CNC. If you need these, the plans will explain it.
Side Note About Plans:
Many people don’t want to spend money for trailer plans until they are sure about building it. They want to know the cost first. Yet, you will need the plans to get an estimate.
Good Advice: Build a trailer to make something Great! Not to save money. (See the article: When Should I Build? When Should I buy? ) The cost of plans is a small fraction of the cost to build a trailer.
Trailer Components Quote
Components are all the little things we purchase (rather than build). This list includes things like axles, hitch, lights, wheels, and bolts.
So, create a list. Include all the items you need for the options you choose, then cross off options in the plans for things you do not want. Next, find the good sources to buy all the parts. (Some suggestions are in the plans.)
For trailer parts, many sources are available. Some online places like etrailer.com have a wide variety. Other places may have better prices. (Don’t forget to add shipping for the cost to build a trailer.) Finally, local trailer parts stores give a personal touch, and can answer questions about what is best for your needs.
As A Side Note: I like etrailer.com for the huge variety, and for all the information they provide about the components (dimensions, ratings, etc.). Yet, when it is all the same, I prefer to buy from local shops to support the community.
Shop around a little. Prices do not vary that much for parts of similar quality, but there is a huge difference in quality available. That means big differences in cost – from cheap and weak – to overly expensive. As you select parts, make sure to consider quality as well as price.
To Save Time And Hassle, most of our trailer plans now have a full parts kit available through Johnson Trailer Parts. The kits include axles, lights, jacks, etc. specifically for our plans. (Not the steel or other raw materials).
The parts are good quality, because we chose them. Also, Johnson will help you add or remove parts from their kit if you want different options. Follow the link if you want a full kit without the hassle of finding each part yourself.
Choose How You Will Spend
For trailer components, there is often a big difference in part quality and strength. Tires are a good example. You can buy the cheapest trailer tires if you want. But, we recommend get good quality tires that are rated for 10% – 15% more load than you need. It will cost a little more up front, but save big in hassle or failure later.
We can make the same argument for the tongue jack, the hitch, safety chains, etc.. I always recommend buying a hitch that is rated for much more than the trailer. In this way, I am spending a little more for peace of mind knowing the rating exceeds the need.
For a tongue jack, I find that when you are near the jack limits, you can feel it. If you buy one with a higher capacity, it will be a little more expensive, but perform smoothly at the loads you will put on it.
Of course, it is up to you. My values may not align with your values. However, please consider where additional cost to build a trailer creates greater value for you in the end.
Raw Materials Quote
For a raw materials estimate, you can submit the Bill of Materials right from the plans if you want. However, if you have the ability to cut it – hopefully you do – then, it helps to buy full length bars. Full bars are usually 20 ft or 24 ft length. This is a good way to reduce the cost to build a trailer.
Unfortunately, raw material prices fluctuate wildly, even from one part of the country to another. I have a client in Arizona who finds a pretty significant price difference from the steel retailers near Phoenix. Sometimes one will be less for certain items, sometimes another. It really depends on prices the suppliers pay, and when they buy it.
You can also check online vendors – steel sellers – like onlinemetals.com and others – to get a feel for prices. In my experience online retailers are more expensive – sometimes a lot more expensive – when considering the shipping too. However, these websites do give perspective on prices. I like online retailers when I need a short bit of something. Otherwise it is usually less expensive to get full length sticks from my local steel yard.
A Personal Example:
For the top, 8″ I-Beam of a new gantry crane, I did not want to buy a full 24 foot beam. (I only wanted half.) My local supplier did not have the size, so I bought it online, cut to my desired length. It cost more per foot, yet even with shipping costs it was less than a full stick ordered locally. And, now I don’t have an extra beam section hanging around.
Make sure to get multiple quotes. Price out the material from at least 3 sources to be sure you are getting a good price.
Unfortunately, buying steel and commercial components is not as stable as consumer markets. – Can you imagine the public outcry if Walmart changed prices up and down every few days? Anyway, industrial suppliers do not take as much profit margin, which is partly why prices fluctuate with the world markets.
For ways to save money on materials and construction, please read the article on How Much Will It Cost? (Scroll down near the end of the article.)
More In The Cost To Build A Trailer
Beyond the cost of materials and parts to build a trailer, there are also other extras to consider. Things like the consumables for welding, grinding, cutting, sanding, as you fabricate. These might not be worth putting in your estimate, so I mention it for completeness.
2 other important areas to consider in costs.
1. Outside Services.
Some of our trailer plans require special shaping or cutting of raw materials. If you need to pay a vendor for water cutting, or CNC work on a part, that is certainly a cost to build a trailer. Look through the plans and figure out what parts you want to fabricate by someone you will need to pay.
When needed, our trailer plans include the CAD files necessary to get parts made. See the download package and read about it in the instructions. Send the CAD files to a vendor to get a quote. Check local vendors (like waterjet cutting) and online sources like we did for the parts in this trailer tongue example.
2. Cost of Labor.
There is a time cost for labor to build things like a trailer. Some people consider their time as a cost for a project, and other people think of it more like a fun hobby. For some people, if it requires actual cash, then it is a cost, but time is not a consideration.
Whichever way you like to think about it, make sure you include the appropriate values.
Assumptions In Asking About Cost To Build A Trailer
I realize it is not really part of the original question about getting an estimate, however, there is often an inference about saving money by building your own trailer. This may not be you, but if it is, I offer this as a final thought with the topic.
Don’t build a trailer to save money. If cheap is your goal, you will make regrettable decisions and compromises in your build.
While it is possible to build a trailer cheaper than you can by a new one, that is not likely. If you want an inexpensive trailer, buy one used – craigslists, ebay, and others. Really, if your goal is low cost, then building a trailer is usually the not the right approach.
On the other hand, we always recommend that you Build It To Achieve Something Better —
- Pride of building it yourself.
- A high quality end result.
- Build to have features not available when buying one.
- For the education (because experience is the best teacher).
- As a hobby – because you enjoy creating.
- Or, to do something that an off-the-shelf trailer will not do.
- Build a trailer to make it uniquely yours.
Yes, Absolutely! – Build a trailer for the intrinsic value that money can’t buy. While cost is certainly important, money should not be the driving reason to build a trailer. At least that is my opinion.
Read more info is in the article “When Should I Build? When Should I buy?”
Build it well, and it will serve you for a lifetime!
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