The windows at Woodlawn, arguably the most elegant architectural feature of the residence, have been fully restored in the woodworking shop of Oak Grove Restoration, and reinstalled at the Mansion after a nine-month campaign that included more than 65 windows. The well-documented project (see slideshow below) was supported by grants from the Historic Sites Fund of the National Trust for Historic Preservation, which were matched in part by private donations.
Woodlawn is a Federal and Colonial Revival estate near Mount Vernon, given by George Washington to his adopted daughter, Nellie Custis. The residence was designed by William Thornton, the architect of the Capitol. Later the site hosted Quaker and Methodist groups that launched an experimental abolitionist community in the antebellum period. The wings and hyphen were heavily renovated in the early 20th century, adding the distinctive Colonial Revival elements.
The twelve-over-twelve, double-hung windows of the main block date to the original construction (1805) and proved to be irreplaceable in design, craftsmanship, and material. These first-growth cypress windows had not been restored since the house was built, and after this careful restoration they will continue to grace the building for generations.
The windows are composed of straight grain, heartwood which is knot-free and naturally rot resistant. Constructed without glue, the windows have mechanical connections such as mortise and tenon joints with dowel pins and locking wedges. The thin muntin bars are held in place with tension created by the dowel pins.
In locations where the wood was damaged, dutchman (wood-grafts) repairs were employed using mahogany placed with the grain oriented to match the host timber. New wood pieces are connected with scarf joints (two pieces joined on an angle) adding to the durability. Epoxy was used in locations where the grain pattern was too short for dutchman repairs, such as on the oval windows.
The windows were primed and painted in the shop and reinstalled in the openings with new sash cords and bronze weatherstripping. Many of the sills also needed repairs after years of weathering. The sills under the dormer windows were patched with wood dutchman repairs since water dripping from window air conditioning units had caused them to deteriorate. We added copper flashing to these sills to prevent future deterioration.
Ultraviolet film was applied to the windows to protect the interior from harmful UV rays that would damage wood floors, furniture, and collections. The glazing compound was replaced, and severely damaged hand-blown cylinder glass was replaced with restoration glass that mimics the imperfections of the early glass. These exquisitely designed windows should last another 150 years before they need another full-scale restoration.
Currently the basement windows are being restored which will complete the window campaign by early summer.
What We Learned
There are a number of considerations to keep in mind when tackling a building-wide window restoration.
Scheduling. We didn’t want to remove all of the windows at the same time because once the temporary plywood coverings were installed, there would be no light in the building. So we restored the windows one facade at a time. Performing the work in stages also allowed us gain some cost efficiencies as we learned how much each window actually would cost and then could adjust the pricing accordingly for the rest of the project.
Numbering System. It’s important to number or label the windows immediately as they are being removed from the building and before they are driven to the shop. It would be very easy to confuse proper placement if a systematic labeling system was not used.
Paint. It’s always best to paint the windows (primer and two coats of paint) in the shop before reinstalling them, as the conditions are controlled better than they are in the field. Be aware, however, that often contractors do not include the interior sides of the windows in their prices as the interiors often are different trim colors in each room. Fortunately, all of the windows at Woodlawn have the same interior paint color. It is important to pay attention to this detail during negotiations.
Hardware. While the exterior wood jambs were mostly in good shape, deterioration occurred where the hardware connected the shutters to the building. Over the years, water had collected behind the hardware gradually rotting the wood. Therefore, when reattaching the shutters, we repaired the wood on the jamb with dutchman repairs underneath the hardware locations.
Edit: More images here.
More on Retrofits for Energy and Cultural Preservation from The Green Economy.