Adding on to an existing house can be tricky. These architects dealt with previous bad additions, cramped layouts, and setback requirements.
Factors to consider, hidden expenses, and sage advice from three architects.
WHETHER A HOUSE is on the National Register or is simply from an earlier era, a host of factors must be considered even before interviewing a contractor or architect about building an addition. Site conditions, materials, budget, and how the new will relate to the old are issues as important as the program for use of new space.
The first is cost.
Additions to historic houses are typically more expensive per square foot than those on newer homes. “If we’re talking about a historic house, we’re talking about historic appearance, materials, and character,” says David Heide of David Heide Design Studio. “There’s nothing basic about that. Everything [the owner] is trying to do with regard to their house has to be custom made. Each time you work with an old house it’s unique.”
Even a modest addition to an old house can be expensive. “The cost that comes with something like this is in the attention to detail,” agrees Howard L. Miller of The Johnson Partnership. Although the remodel on p. 66 was not even 100 square feet, “it cost a bunch of money because we carried over the details of the house.”
Old houses are also subject to more concealed conditions than are new ones. Examples include broken ridge boards (look for a telltale sag in the roofline), rotten floor joists, and obsolete wiring and plumbing. All must be addressed before new construction can begin, says architect Sandra Vitzthum. “Quite often, renovation can be more expensive than building from scratch.”
It’s helpful to have an architect or builder who is experienced in negotiating with local agencies regarding setbacks and the zoning and building issues that come up.
A good architect or contractor will talk about budget from the beginning, and once the initial plans have been thrashed out, will interview contractors and get estimates for the scope of work, says Miller. From there, the budget can be adjusted up or down depending on what the owner can afford or wants to do.
Since older houses in cities and towns are often built close together on lots that no longer conform to modern subdivision regulations, “the first thing we do is look at the lot lines, the size of the lot, and determine what the limitations are, including any height restrictions,” says Heide. “Any responsible architect should do that before the first meeting.”
It’s also helpful to have an architect or builder who has experience negotiating with local agencies to resolve building or zoning issues posed by a historic project. In Seattle, for example, many houses in older neighborhoods were built 3' from the property line. Now the required setback is 5', but “there’s a certain amount of accommodation in the Seattle city code,” says Miller. “If the house was already built at 3' feet from the property line, they will let you extend your house at the old 3' setback.”
Whether you work with an architect or not, it’s a good idea to find a contractor who is familiar with old-house issues. “I’m always impressed with a builder who, before they even start the addition, says ‘this existing floor is out of plumb by an inch and a half,’ ” says Heide.
A good contractor will understand the importance of leveling the floors between
the original part of the house and the new one. “They plan for it,” continues Heide. Since old houses are rarely plumb, “sometimes it’s a combination of lifting one side and lowering the other.”
Arm yourself with knowledge to decide what elements of the existing house you want to keep, especially when dealing with a builder “who may have good intentions, but prefers to rip out the old because it’s less trouble,” says Vitzthum. “Plaster should be kept if at all possible. It’s actually more sound deadening than Sheetrock, and it’s an all-natural material.
“Quite often a contractor will say, ‘You’ve got to rip out the windows and walls and insulate’, but what they don’t tell you is that two-thirds of a building’s heat is lost through the roof. It makes so much more sense to leave the walls alone and put all of the effort into insulating the attic,” especially in colder climates.
Finally, be willing to discuss with your architect or contractor some of the intimate details of how you expect to live in the new space. Be ready to talk about money, privacy, and even parenting as well as your reasons for expanding the existing house. Sometimes a smaller addition or simply rearranging existing space can solve your issues with less fuss.
Bear in mind that the scale of any addon should be appropriate to the original scale of the house. “You don’t want things disproportionate,” says Heide. “One should let the house tell the story of its evolution. But from our client’s perspective, if it’s seamless, we’ve succeeded.”
The builder may have good intentions— preferring to rip out old material because that’s easier. Owners must be clear about what to keep.
A farmhouse pantry tucks behind the kitchen; the stairway leads down to a new laundry room. Additions dating to mid century made the dining room the darkest in the house. INSET
OPPOSITE (before) The garage and patio were crammed into a miniscule backyard. (after) Reclaiming space from a patio and extending a terrace and pavilion over a new below-grade garage opened up ample outdoor space with sight lines to a lake.