Q: Can I buy my own fixtures?

A: In most cases, no. The brands and models that professional builders offer are those that have proven reliable and come with solid warranties. Items like toilets sold at home centers may be different than those sold to pros through plumbing distributors, even if they’re from the same manufacturer. The pro model will generally use higher quality parts and allow the builder to stand behind a product during the full warranty period.

The work of building a price and schedule for your custom home is a project in itself.

There’s a reason that quality project estimates don’t happen overnight. Every home is a collection of thousands of individual components that range from large-scale assemblies like walls and roofs to small items like doorknobs and faucets. The builder has to consider every one of these elements when projecting what it will cost in time and materials to complete the home.

How long this takes varies by project type. For instance, a production builder that builds the same plan over and over will be able to generate estimates on the spot in its design center. That’s because even though the company offers some options to buyers, it’s really mass-producing a cookie-cutter product.

Custom homes are different because each one is unique. An estimate for a simple custom home can easily require 60 hours of staff time, and even more if it’s a complex architectural design. The logistics of getting the estimate done means those hours will likely be spread out over several weeks.

The builder needs to calculate the time and expense for everything from having the plans reviewed by permitting agencies to framing the shell and installing the roof, mechanicals, interior finishes and landscaping. Assembling all these numbers is a massive project that requires experience, knowledge and organizational skills. And, of course, time.

In addition, the builder needs to ensure that the products being priced for the home are the ones the customers want and that the budget will support. In many cases, this means investing time to complete the plans and clarify the product specifications, or specs.

People come to the table with dramatically different assumptions about costs, so the builder needs to clarify these assumptions. For instance, the home’s overall quality level may indicate that it’s safe to base the fixture allowance on standard Delta brushed-nickel faucets, until a discussion reveals that the homeowners are imagining something more expensive. This clarifying work may need to be done for every line item in the estimate.

The builder also needs to solicit prices from each trade subcontractor that will work on the home, from the excavator to the plumber and painter. This can be the most time-consuming part of the estimate. If getting the subcontractors’ bids in house weren’t enough of a challenge, those bids also need to be put under a microscope.

That’s because the builder needs to make sure that subcontractors’ estimates are realistic. For instance, if a drywall bid seems low, the builder has to know enough to ask the drywall contractor how many sheets the estimate was based on, and someone on the builder’s staff needs to check those calculations. When asking for bids from 30 trade subcontractors, it’s not unheard-of for one or two to submit inaccurate bids because they were busy and needed to get their estimate to the builder on deadline. That’s why bids must be carefully reviewed.

All this work is about getting the estimate right. Taking the time to do a thorough and accurate job today will save time, expense and headaches tomorrow. It’s an area where patience pays real dividends.