The addition of a wood fireplace offers home owners a higher return on investment that any other amenity. But fireplaces are not easy additions for everyone. If a house doesn't already have a well constructed chimney, fireplaces require that a professional mason construct one. But, for those who do already have a chimney, and who wish to either add a new fireplace or replace an existing one, the installation of a wood-burning fireplace is a doable project.
Measure the space within which you are trying to install your fireplace. Make sure that the space you are measuring is no less than 36 inches from the nearest combustible wall. If the space you are measuring is near a combustible floor, build a hearth, typically out of slate or brick, extending at least 2-1/2 feet from the mouth of the fireplace. To do this, use an electric saw to remove an area of combustible floor large enough to house your hearth. Layer mortar on the floor and place the bricks or slate on top of the mortar. Use more mortar to fill the spaces between the bricks or slate. Let dry overnight before continuing your installation.
Select a fireplace-body that fits your alloted space. These solid metal pieces are the building block of any fireplace unit, and tend to take up 3' x 4' of space. For smaller spaces, consider portable gas or electric fireplaces.
Slide the fireplace-body into your allotted space. If the fireplace is too small, you can build out the chimney space with bricks and mortar. Clean the chimney space with soap and water, then use the same pattern of bricks and mortar present in the existing chimney space as a blueprint for your brick-work. Hold the newly mortared bricks in place overnight with 2" x 4" wooden boards. If the fireplace is too large, no adjustments can be made without compromising the structure of the chimney or the fireplace.