Architects and design-build contractors have heatedly debated the relative merits of two design and construction approaches for about three decades. The truth: There are arguments for either method, even after you throw in a green twist.

Under design-bid-build (the “traditional” method preferred by many architects), the owner contracts with the architect. Then, after all or most of the design documents are ready, the homeowner contracts separately with the builder, sometimes with the help of the architect.

plans 2For more on selecting a custom residential architect, click here.)

Under design-build, the owner contracts with one company  both for design and construction. While architects lead some residential design-build companies, the bulk of them are controlled by builders. Small design-build companies seldom have licensed architects on staff. Instead, many contract with designers (often un-licensed architecture school graduates) to build custom houses from scratch; some even hire designers to customize stock house-plans purchased off the Internet.

The upshot is that a design-build firm may not provide the depth and originality of design you’d get with an independent architectural firm — though, in fairness, that’s not always the case.

Many architects (especially those that compete with design-build companies) also argue that there’s an inherent conflict of interest in having the builder also employ the designer: That arrangement gives the design-build company less of an incentive to watch costs closely and more of an incentive to design in more expensive features because the fee is set a percentage of the budget.

The contrast is stronger when compared to arrangements under which the architect helps “administer” the construction phase: In that case, the owner has an advocate to oversee the builder’s work quality and expenses; with a typical design-build contract, the incentives all run on the side of inflating costs.

But wait! There’s a flip side to this coin. Whatever the alleged conflict of interest, academic studies have found that design-build to be costly than using an architect, and that it typically takes less time. If you think about it, there’s a good reasons for that: At a good design-build company, the designer and the builder work as a tight-knit team. Just the fact that they know each other and work together a lot is likely to make things go more smoothly.

Plus, with design-build, designs don’t have to be detailed out, wrapped up and tied up in a nice bow before the contractor starts lining up sub-contractors and even starting construction. If something was left out of the plans, or if a change needs to be made, there’s not a lot of dickering over whose fault it was and who’s going to have to pay for it.

Which brings us to another big, practical consideration: liability. If something goes wrong, there’s no finger pointing between the architect and the builder; the design-build firm is going to have to deal with it.

(For more on the relative benefits of the two approaches, here’s a succinct debate between an architect and a design-builder.)

Green considerations could argue for you to go in either direction. Obviously, it’s easier to coordinate between design and construction — a fundamental part of any green project — if both are being done by the same team. On the other hand, the intricate challenges and emphasis on quality work that go with any green project might make the skills of an architect and the oversight that can provide over the builder more important.

Of course, custom architecture and design-build are far from the only approaches. If you’re building a house on a tight budget, stock house plans may be the way to go (for a full discussion of that plans, click here; for a fuller discussion of all options, check out this article.)

One other thought: If you have a pretty solid idea of what you want and a design-builder in mind who seems like a great match for you, design-build may work best for you. If you don’t know where to even begin thinking about your new home, it may make sense to work directly with an architect.

If you do decide to go with a design-build company, make sure it’s a good one — with key players who have an ethical reputation. Of course, that’s important for anyone you hire, but it’s a particularly big deal when it comes to design-build — not just because you’re putting pretty much all your eggs in their basket, but also because there will be nobody but you to oversee them.