When heading in to a project such as a new kitchen or bathroom, it is hard to determine what it takes to put these things together. It is far more than selecting a cabinet door or kitchen sink color. These rooms are heavy on fixture and equipment specifications. A qualified kitchen designer will be knowledgeable in the structure of how homes are constructed, HVAC, plumbing, gas, electric, appliances, cabinet construction, and material properties. All these things are complex on their own, plus one needs to know how they all work together. That big range you've been pining over could easily mean a new HVAC system for your home if you are remodeling, or a bigger system if you are building a home. This expertise will save the homeowner time and money while ensuring a desirable outcome.
I don't know about you, but I definitely have budgets I need to stick to, and so do my clients. We have a close network of vendors we work with to assist with selections. By being up front about your budget and needs and wants, we are able steer you toward the appropriate avenues and have options ready to show so you do not get overwhelmed when walking into a showroom. Remember to reserve part of your budget for unexpected surprises found once demolition starts. I have been awarded several projects when homeowners attempted to do their kitchen remodels on their own through a big box store. Going this route may seem attractive at first, but once you need to start making corrections and doing things over, the costs end up being far hire than if you were to hire seasoned professionals from the beginning.
For an additional view point, try the article linked below to Better Homes and Gardens. Also check out resources at the NKBA https://nkba.org/.