When a house is fully insulated, it's also more pleasant. When the kids jump overhead, the ceiling fixtures won't swing and the dishes won't rattle in the cabinets. Insulation is very inexpensive and increasing the r-values will make the home more efficient. Adding insulation into the interior walls can dampen noises within the home. 

Owners are frequently tempted to cut back on those essentials to make a project come in on budget and still get the oak floors and granite countertops. However cutting back on the infrastructure of the home could cost more utility bills and maintenance costs. Here is a great tool to help you estimate costs

Most builders say clients usually resist putting money into things they can't see but people are amenable  when you explain not only what to do but also why to do it.  It helps when the person doing the explaining has no vested interest in profiting from the home. 

Where the climate is fairly benign as we have here in the NW, you won't benefit from thicker walls with more insulation as much as someone in Anchorage would. The type of insulation you use can  make a big difference in the comfort of your house. Blown-in cellulose insulation made from recycled newspapers will  reduce air infiltration, which can make rooms drafty in winter. The insulation makes the temperature more even throughout the house, and it deadens sounds from outside.

Windows are another area where you do not want to pinch pennies.  When a house comes in over budget, windows are a tempting target because it's possible to substitute cheaper ones and lower the cost without altering the design. But over time, window quality will affect the ambiance of a space and your enjoyment of it. Everybody wants big windows that flood a space with natural light. But cheap builder-grade windows are generally less effective in stopping heat loss, so they're drafty in winter. In a few years they tend to leak, and the vacuum seals between the two panes of glass often break down so that the condensation fogs the glass.

Windows won't frost in North Puget Sound's mild winters, but the weather there must be taken into account when choosing them. Salt air, wind and sun can ravage the exterior of houses built near the coast. Some clients want to save money on the exterior to get more sizzle inside, but what you save up front will cost you in maintenance down the road when you have to replace the windows

We recommend high quality windows such as clad wood windows (the exterior side of the window is vinyl or aluminum that is finished with a highly weather-resistant paint) on higher end homes.  However, there are many vinyl windows that have good appearance and quality. Most glass today is low E. This type of glass reduces the amount of heat transfer while allow light transmission.  This is a must especially where you have a room with a lot of glass. There are also triple pane windows available but with our mild climate we don't see enough energy benefit to justify the cost.

Though many clients have a hard time getting enthusiastic about extras they won't see, all the builders said customers can have even more problems with what they can see and are enthusiastic about. The number of decisions that must be made can overwhelm even the most decisive business executive. Take your time and don't be afraid to consult the experts before you make your decisions. Changing you mind mid-project can be frustrating, expensive and can cause delays.

Have you considered the convenience of a utility sink in the garage?  Very handy to have for washing up after yard work, auto maintenance, or any other activity.  If there is no room for a sink how about a house bib in the garage with hot and cold water?

Outside receptacles for future landscape lighting requirements, Christmas lights,  yard maintenance equipment, and so forth.  One outlet minimum for front and back of the residence is recommended.  With the number of rechargable devices, how about extra outlets in closets for these devices?

Most codes only require 1 receptacle for the garage.  For me, more is better. If your planning on a work bench, have the electrician add lots of outlets

Ensure water hose bibs (faucets) are available on the front and back of the residence.

Insulate interior walls surrounding master bedroom will afford improved privacy.  You might want to consider insulation for any 2nd floor waste lines over areas such as the dining room.

Gas lines connections may be necessary for any future dryer or kitchen oven requirements.  Is your home already outfitted with these? You can virtually eliminate the hassle of changing propane bottles on your barbecue grill by having your builder install an exterior natural gas line for your back deck or patio.

Ceiling fan provisions can be easily done prior to the drywall installation.  You don't have to purchase the fans before you move in.  However, the ceiling supports and wall switches can be readied by your electrician for any future plans you might have.

If you're the type of person who likes to rearrange furniture from time to time, are the quantity and location of cable/telephone connections suitable?

If your planning on surround sound in the den or living room, ask to have AV wiring put in. Some builder will have their electrician do it or you can contract with a specialty company