ONE AND TWO-STORY ADDITIONS
If you need more space and your site permits, consider building a one- or two-story addition rather than adding dormers. Because many of the original owners used a different material or siding on their additions than on the original buildings, you should do the same. Generally, housing or garage additions are structurally separate, built to the side or rear of the main structure, have their own foundations, and often lack basements.
It should be clear that additions are later features and not part of the original structure. There should be no confusion as to what was original and what was added later, and additions should be clearly subsidiary to the original building. This can be accomplished by providing a clear visual break between the original building and the addition, by setting the facade of the addition back from that of the original, or by constructing a recessed area at the point the addition and the original building join together. See Drawings 18, 19 and 20 on left side bar .
2. Change of materials is another way visually to distinguish an addition. On a brick building, for example, a frame addition is a very appropriate way to accomplish this differentiation. See the Siding and Masonry sections for guidance on selection of treatments.
3. Another approach to make an addition "read" separately is to use different detailing. Simplified cornice details, or window and door trim of a slightly different dimension from that on the original building, for example, can provide subtle visual clues as to where the addition begins.
4. A creative approach could be to make an addition essentially a free-standing structure, connected to the original building by a modest glass-walled connector designed to be as transparent and unobtrusive as possible. This same approach should be used to link adjacent existing buildings as an alternative to building an addition. When such connectors are used, they should be placed as far toward the rear as possible, not at the front part of a lot, and they should be only one story high. They should be simply detailed, with no attempt at ornamentation, and they should be painted to match the building's trim color to make them blend in as much as possible.
5. Additions should be placed to the rear of a building wherever possible. An extension along existing building lines toward the rear usually does not require a zoning variance, though it could if too much of the lot area is covered by the building. See the Zoning chapter.