The evaluation of a quotation is in itself an "art" and in principle only reserved for skilled and experienced engineers or architects. The "art" is to find the hidden loopholes in a quotation and the comparison of "apples to apples". However, no need to be an expert if you wish to evaluate a quotation for a Timber Prefab House, as in fact this is a straightforward exercise if you follow the tricks, tips and hints given below.   

Assume that you have inquired for a quotation from 3 different manufacturers, either based on their standard models or based on a drawing made by yourself or your architect. Before you start you need to define the weigh factors, i.e. what is most important to you.  Example: You will build the house in a cyclone area. Most important is that the house will remain in tact during a cyclone (at least for the greatest part). You may give this a weigh factor of 1. Other important factors may be that the house shall have termite resistant timber, a coating system with a guarantee of at least 3 years, stainless steel fixtures, double sidings, roof decking, low floor deflections, no nails used, the durability, the price, the payment system, lead time and many more. Each of them shall be given your own importance weigh factor. In conclusion, before you start an evaluation you need to prepare a list with items followed by a weigh factor for each of the items plus a list of your requirements. The next step is that you obtain specifications from the supplier (what we have already done for you on our specifications page).
With the specifications in hand from the 3 suppliers you start your evaluation. Each and every part of the quotation that does not fit or match your requirement shall be given a lower weigh factor. Example: You wish double siding boards with a minimum thickness of 25 mm each. Your chose a weigh factor to this requirement of 0.7. One of the quotations proposes single board sidings of 25 mm thick. You may give this a weigh factor of say 0.5. The second supplier proposes double board sidings with a thickness of 16 mm. You may give this a weigh factor of 0.55. The third supplier complies with your requirement and proposes double siding boards with a thickness of 25 mm each. The weigh factor shall be 0.7. You repeat this for all the items and summarize the weigh factor for each supplier. Now comes the trick to know which of the suppliers has submitted the most responsive bid (hence most advantages for you).
This part of the evaluation comprises two aspects, viz; the price and the technical compliance (weigh factors). Step 1: Divide a figure of 100 by the summarized weigh factors. Step 2: Divide the price that each supplier submitted by the resulting figure from the previous calculation. The highest score is the supplier who submitted the most responsive bid.

Example:
Supplier 1:  Summarized weigh factor is 14.85. Their price is USD. 75,000
Supplier 2:  Summarized weigh factor is 12.35. Their price is USD. 68,000
Supplier 1:  Summarized weigh factor is 17.65. Their price is USD. 83,000

Score of supplier 1: 100/14.85 = 6.734  Price/quality ratio is 75,000/6.734 = 11,138 
Score of supplier 2: 100/12.35 = 8.097  Price/quality ratio is 68,000/8.097 = 8,398 
Score of supplier 3: 100/17.65 = 5.665  Price/quality ratio is 83,000/5.665 = 14,651 

The obvious winner is supplier 3, despite its higher price. Though the calculation is merely based on axioms and arbitrary parameters it will give you at least a good insight in the responsiveness of a bid. 

The above is a very simple example of how it actually works in the world of construction, be it that large projects (in the millions of Dollars) do have much more complex weigh factor systems which also includes the number, skill and experience of the employees working for the supplier, project references, financial statements, presentation of the quotation, guarantees, lead times, etc.

To help you with a simple weigh factor system (by far complete), refer to the table below (this is just an example. P.T. Bali Woodworld will not accept any responsibility in the case of errors, or otherwise). A very good weigh factor table may contain over  50 items.

Good luck

The Management of P.T. Bali Woodworld