Whether or not you've put it on paper, or even if you're not consciously aware of it, as a homebuyer you no doubt have a mental list of "make or break" items for a new home. For homebuilders, the question is how to include as many of these "must haves" as possible. That turns out to be not-so-easy because consumers have differing requirements.

A study by the National Association of Home Builders, "What 21st Century Home Buyers Want," examined 89 different characteristics, products and features in ten broad categories. It then asked respondents to say which items would most influence purchase decisions.

Surprisingly, few of the items on the list were deemed "Essential/Must Have" by large numbers of those surveyed. In fact, the only feature a majority of respondents said they couldn't live without was a laundry room.

Many did deem some bathroom features essential: 42 percent said they must have an exhaust fan, 32 percent considered a bathroom linen closet essential, and 20 percent had to have a separate shower enclosure.

Inside of the house, only two other features ranked as essential by more than 20 percent of the respondents. A dining room was a must have for 36 percent and double-pane windows were critical for 21 percent of those responding.

The other features more than a fifth of the respondents called essential were outside the home. The top three finishers: fenced yard, front porch, rear deck.

Survey respondents could also define a feature as "desirable," something that would seriously influence their decision to purchase a home. Here's the top ten list of features marked desirable or essential:

1. Laundry room

2. Linen closet

3. Exhaust fan

4. Exterior lighting

5. Front porch

6. Deck in rear

7. Lot with trees

8. Dining room

9. Walk-in pantry

10. Patio in rear

The NAHB puzzling over some of the results.

The organization report found it peculiar that something like exterior lighting was deemed so important, since it can be added later much more easily than a built-in feature, such as a walk-in pantry.

Among the built-ins, such as laundry and dining rooms, respondents also expressed considerable interest in having such specialty rooms as a home office and den/library. Just under half of those surveyed rated a sun room as essential or desirable, 29 percent wanted a media room, and just 22 percent wanted an exercise room.

When surveyed about decorative items homebuyers most wanted, built-in shelving topped the list. Seventy-two percent of respondents called it desirable or essential. Other popular items included ceiling crown molding, fireplaces and window seats.

Builders may now have to go back to the drawing board and come up with a new must have list of their own.

Carol Ochs is a Washington-based reporter who covers new home trends.