Order a house plan from an architect or a construction company?

When planning to build a new house or an addition to your current home, everyone has a question: Who will do the work well?  

 Should you first hire an architect to design and plan the house and then turn to builders or subcontractors for further construction?

Or should we instead turn to a "design and build" firm, which not only has its architects but is also the general contractor responsible for the construction work?

Both options have advantages and disadvantages. Here's a quick overview to help with your project:
Do your research on the market for building materials and services.
Remember that success may depend on how well you've researched the reputation and testimonials of previous customers of competing firms in the construction market. You need to get references and talk to customers who have tried to build homes or additions similar in scale to what you have in mind.
Key differences:
When you hire an architect to design and create plans, you can get precisely what you want in design and your wishes. Suppose your contract requires an architect to be on-site to check the quality of construction and compliance with building codes at every stage of the project. In that case, you also get an invaluable professional to protect your interests. The architect is not interested in creating substandard calculations of loads, assemblies, etc. It makes no sense to save on building materials, and it is essential to do a project by building standards and SNIP. And, of course, the architect is not imposing materials on you, making a profit from sales; he listens to the client's wishes, considering his knowledge and experience.
However, since there is no one party responsible for everything - the architect's primary responsibility - design, and the builder's - construction, there may be conflicts that put you in a bind. One crucial issue is that the architect's initial design may not be within the previously planned budget, something you won't discover until after the builder's bill. Then you may have to increase the cost either, or you may have to abandon your plan for the initially intended house.

Controlling the procurement of construction materials will help eliminate such a situation.
In contrast, with a design-build firm, you typically set a budget and schedule in advance and then work with the design professionals provided by the firm to come up with a final plan that can be achieved within your budget and time frame.
The design-build firm includes a general contracting division that should be familiar with construction material costs and have working arrangements with a network of subcontractors, so surprises in budgets before and during construction should not be a big problem. When designing and building, you have a single company in charge of the entire project, and for you, paying the bills, a single point of contact to track the progress of the work.

However, some critics argue that if there is a conflict over any aspect of the project, you are the only party representing your interests in the project. And that puts you at a disadvantage since it is unlikely that your knowledge of construction or materials lets you know when you are being overcharged or the work is not being done correctly. It's also not a pretty fact that firms often impose material left over from a job on another site that doesn't match the standards of your plan's requirements.

Other thoughts and tips:
Working with a reputable design-build firm is often a less costly option because internal communication between the designer and the construction team saves time and is governed by the essential requirement of staying within the contracted budget.
The success of either approach may depend on how well you research the reputation and previous work of competing firms in your local market.

In an architectural-build approach, a large part of the design-build fee is devoted to making design details and drawings crystal clear to contractors and working with the client and contractor during project construction. In design-build, some of this cost and time can be avoided. This helps maintain the integrity of your approved project and reduces final bills.
Also necessary: Most design-build firms have a process for selecting cabinets, countertops, plumbing fixtures, kitchen appliances, and other building products used. This can make choosing these items more accessible and cheaper than paying an architect to select for you. Or, even worse, having an architect instruct you on what choices you should make to fit the architect's "vision" for your new home. Remember, of course, that you, the client, can be guilty of too expensive a taste, so it's not always just the architect's fault.

Suppose a design-build firm does not work with, or not all work with, a registered architect. In that case, you run the risk that the builder will take over the design function without the necessary certifications, training, and liability insurance. Make sure you verify the professional qualifications of the designers. Also, if you are focusing on a custom home design or remodeling project, you may be better off hiring an independent architect known for his work.
When you research a particular design-build firm and talk to previous clients, ask how the company handled design changes that occurred at the client's request during the project. Did the company have financial controls to alert the client to additional costs caused by changes in the original plan? If a good process is lacking, the result can be significant, unexpected cost overruns - one of the very problems the design-build concept was intended to avoid.
Finally, whichever option you choose, make sure you and the design-build or architectural-build team have a well-designed contract with specific construction benchmarks tied to financial drawings. Before signing any contract, consult with a local lawyer specializing in construction law to make sure that all parties are clear on terms and deliverables and minimize the possibility of future disputes.