In some cases you may want to obtain bids from other custom home builders once you have your design and plans established. However, keep in mind that you must be sure that you are comparing apples to apples when getting prices from different sources. All materials and finishes and specs must be the same to get a true comparison.
Make it clear that any changes or substitutions for product must be indicated.
Price is not always an indicator of the best value. Quality in all aspects of the custom home building process is what matters. The most expensive materials will not perform their best if shoddy workmanship is used and lesser cost materials may perform very well if installed in the best way possible to achieve peak performance.
To obtain bids on specific parts of the job for each trade you should follow the steps listed here.
Review your list of potential subcontractors
Finalize all design and material requirements
Prepare standard specifications for the job
Prepare packages containing Sub Information Sheet, Standard
contract Terms and Specification sheets
Contact the subcontractor to discuss plans, mention forms to
complete and deadlines and get an understanding of who provides
what
Receive and evaluate the bids
Select top three based on price and your personal assessment of
the sub.
Compare bids to budget
Negotiate with the sub for the best cash price
Select your sub and advise him that he has been selected you
need commitment for specific period of time for the job.
Keep in touch with subs and let them know of any changes to the
schedule so they can make other plans and when they are
expected at the site.