You must also consider what you want to do with the space that's present in your attic at the very moment. You may also wish to expand your attic while converting it and this can be done properly as well. Should you find any specific task that you want to complete after that, it would also be ideal to prepare them ahead of time. In a project such as this one, timing is everything and an experienced contractor would know how to work things out on schedule.
Attic conversions not only add versatility to your home and it also increases the floor space and re-sale value as well. You can have that office, studio, bedroom or just plain extra living space you have always wanted.
As previously stated, checking for electricity in the space is important, as well as how many junction boxes there are. A single light hanging from the ceiling is not going to be adequate for a living space. If you are planning to include a powder room, see if there is plumbing coming up to the attic. If your home is heating via a furnace and cooled in the same manner, locate the nearest ducting to see if it can be extended. Depending on the size of the attic, the age and condition of the home, it may be necessary to consult a structural engineer. This is an important step. When you are adding so much extra weight to the structure, it is crucial to have an expert evaluate the integrity of the building.
Don't forget to incorporate the position of electrical outlets. Use the elements of the attic to your benefit. If there are load bearing vertical beams positioned in odd places, consider using them for the construction of a bed, desk or shelving. Some large older homes are duplexed or split into condos. If your situation fall under one of these headings, and you share a party wall, it may be necessary to gain permission from the owners association or neighbor.