Eyes on the Yard
Building Renovation, Summer 1994
by Derek H. Trelstad
Completed in early January 1993, Weld Hall looks now as it did when it was originally built in 1870. Brick and sandstone were cleaned and fire escapes were removed, replaced by fire code compliant interior stairs.
The new wood sash installed as part of a comprehensive dormitory improvement program at Harvard University feature true-divided-lites and insulating glass.
Harvard freshmen may be the smartest of the lot. But they are not necessarily kinder or gentler than their colleagues at other schools around the country. So, when the University began a five year restoration program of the 16 freshman dorms on the storied Harvard Yard, the durability of the materials and the quality of the skills that the manufacturers and contractors could provide was paramount. But while the school would have liked the buildings in the Yard, which is a National Register Historic District, to endure indefinitely, budget constraints and a tight construction schedule precluded an iron-clad restoration. What they did manage to pull-off, however, bears testament to the fact that compromise is not always one step down from perfection; sometimes it's better. Particularly when it comes to windows.
Dorms on the Yard had been painted white since the early 1920s. While this single palette had been an enduring part of Harvard's image, the architects felt each building should be painted in colors dating to its period of construction. above.
3 BUILDINGS, 2 CONTRACTORS, MANY WINDOWS
This ambitious project—part renovation and part restoration—began in late 1991, nearly thirty years after Benjamin Thompson and his firm, The Architect's Collaborative (TAC), completed a similar project on the Yard. TAC's approach, stripping back much of the early or original finishes and exposing brick walls, lent a distinctly modern tone to what were then a complex of worn and stodgy dorms. But, by the late eighties, the stark white finishes had begun to gray and the sealer that coated the brick walls had darkened. While the interior was bad, the exteriors were worse. The dorms had reached a state where a simple coat of paint and a good scrubbing were far from adequate to reverse the decay. The roofs leaked, the paint wouldn't stay on the trim, and replacement windows and storm sash were broken. Handicapped accessibility and the capacity of the existing mechanical and electrical systems were also pressing issues that pointed the school toward a comprehensive renovation plan.
Goody Clancy & Associates, a Boston-based architectural firm, handled the renovation of three of the sixteen dorms on the Yard. This article looks at two of these buildings, Weld and Hollis Halls. The third, Stoughton Hall, is similar to Hollis. Because the time scheduled for these projects was short, general contractors were brought on board before design work was completed to work in collaboration with the architect and the owner. Contracts for construction were let to two firms; Beacon Construction for Weld Hall and Shawmut Design and Construction for Hollis and Stoughton. The general contractors bid the subcontracts competitively and eventually selected two window manufacturers to supply the new sash: Architectural Components, a small shop in Montague, Massachusetts, was awarded the contract for the windows at Weld and KSD Custom Windows, another small shop in Tilton, New Hampshire, was awarded the contract for Hollis and Stoughton. While each of the projects required different windows—the number of lites and the muntin profiles of the sash differed slightly from one building to the next—performance and durability standards were exacting and universal.
Weld Hall, built in 1870 to designs by the Boston-based architectural firm Ware and Van Brunt, was one of the first of the 16 dorms to be renovated. Because the University had limited overflow space for the first year class—they had determined the minimum number of beds it could have available at anyone time during the five year project—renovation of each building was kept to an extremely stringent schedule. Weld was one of several consecutive projects for which the University had scheduled a seven month period for construction—demolition could begin after commencement in June and had to be completed by New Year's Day.
Goody Clancy's first contact with the University was in November 1991; the scope of the project was discussed and access to the structure was scheduled during a portion of the winter break—from the day after Christmas to New Year's Day—to conduct investigations and draft preliminary design drawings. Architectural contracts were awarded in December 1991 and construction documents were completed by March 1992.
A MATERIAL THING
Goody Clancy retained the consulting firm Preservation Technology Associates (PTA) to assist in the investigation of the building exterior and prepare recommendations for the repair of the windows and roof, and the repair, cleaning, and conservation of the brick and sandstone facades. After considerable forensic and archival work, Goody Clancy and PTA provided the University with recommendations for the exterior conservation work and a package describing an architecturally sensitive, yet cost efficient and thermally effective, solution of the windows. Several options were presented; single-glazed true-divided wood sash with exterior storm windows, the same sash with a single interior storm panel, and true-divided wood sash with insulating glass. To avoid the maintenance headaches that had plagued the buildings with wood sash over the years, the University insisted that aluminum units also be considered.
A full section of the sash at Weld reveals the similarity of this and the sash used at Hollis Hall. Note, however, that the brick mould, muntin profile, and the number of lites in each sash is different. Fiberglass screens were installed on each window, as much to keep students and their popers in the buildings as insects and other unwanted guests out.
An applied moulded-wood stop was used to secure the insulating glass units from the interior. This puttyless glazing detail was used in an effort t0 reduce maintenance costs and improve durability. It also conveniently eliminated the need to resolve compatibility problems between the seal on the insulating glass and glazing putty
Harvard had worked hard to build a strong relationship with the community, particularly the Cambridge Historical Commission, and made sure they were brought into the decision process. And, in fact, the Commission's experience with other projects in which aluminum windows had not performed as specified was central to the sash selection. The savings the school expected from reducing the need for periodic painting were lost when it noted that the existing trim—cornices, doors, mullions, and dormers—would continue to need painting and that when the finish on the aluminum failed, costs associated with repairing the windows would be considerably higher. The building team and Commission also expressed a concern about the historical accuracy of the new sash; the aluminum sash required a metal subframe, that would either reduce the sight lines (by making the frame wider) or require removal or modification of the existing wood frame. Removing the existing frame was not feasible. The loss of that much historic fabric was unacceptable and it would have been nearly impossible to remove the frames without destroying the existing masonry surrounding the window openings. Lastly, the Commission and the University also wanted to see mockups of the windows. The long lead times for both the fabrication of the mock-up and manufacture of the aluminum windows led the building team, including the school, to reach a joint decision to pursue wood sash options.
Three mock-ups were installed and tested. A true-divided lite sash, with insulating glass was selected as the most durable and maintenance free of the mock-ups—single glazed sash with exterior storms were too dependent on the user for their thermal performance, and the sash with interior storm panels were considered problematic from a maintenance and safety standpoint. Because the applied glazing is flush with the interior face of the sash, there is a tendency for people to hit the glass while attempting to open the window by pushing on the meeting rail. In fact, the glass in the mock-up was broken within a week of being installed.
Because the Yard is part of the Old Cambridge Historic District, the Commission required that work on the exterior the buildings meet the Secretary of the Interior's Standards. At Weld, where the lites in the sash are quite large, this mandate meant the glazing had to appear hand-blown. A local manufacturer built the glass units by hand; standard mechanical fabrication would not have kept the aluminum dividing strip between the panes within the 3/8- to 5/16-inch sightlines of the reproduction windows. (Industry standard is 1/2 inch.) The exterior sheet of each unit is restoration glass made in Germany that is separated from a sheet of standard float glass by a dual seal of poly-isobutalene and silicone.
Once the University had been convinced that the wood sash were the most appropriate choice, the real work began. Windows were ordered as the selection meeting was disbanding; the manufacturers needed as great a lead time as possible and the architects had little time to spare.
As the work of preparing the existing frames got underway, it became apparent that the amount of repair was more extensive than the subcontractor had anticipated. Goody Clancy and PTA worked as a team with Beacon and the subcontractor to establish procedures and standards for scraping, selecting areas for dutchman repair, and epoxy consolidation.
Despite the incredible pace of the project, the building team had done its homework thoroughly, and discoveries and disputes over standards were few. The cooperative environment that had been established at the outset of the project set the tone for the few problems that did arise, which were quickly resolved and had little effect on the tight delivery schedule. The job, new windows and all, was delivered as promised on January first.
Although Hollis, shown here, and Stoughton appear to be twins, Hollis was built in 1763 in the Georgian style and Stoughton, designed 40 years later by Charles Bulfinch, in the Federal style.
While the work at Weld had focused on finding an appropriate replacement sash and minor repairs to the frame, at Hollis and Stoughton the windows had suffered greater abuse. So, while the overall scope of the project on these buildings was not as wide as it had been at Weld—there was considerably less structural work here—repairing the wood window frames that had been damaged less than twenty years earlier when aluminum windows were installed was a considerable task. And, with a two and one-half month slot to complete the renovation (work was to be completed during the summer intersession, between June and August 31) there was a lot to do in a little time.
TEARING OUT THE TIN
Because the schedule on this project was so short, and the building was occupied, access for investigations was limited to a few representative areas. Only a single aluminum replacement window and its panning systems was removed to document the existing and original conditions. When the aluminum windows had been installed, the contractors had torn-off the blind stops, much of the moulding, and several of the outermost edges of the sills. Despite the damage, PTA and Goody Clancy uncovered evidence of the original sash thickness and weight pockets that had been cut out from the solid 3 by 5 inch frame sections. The original sash was approximately 15/16 inches thick and had broad flat muntins. These sash were replaced during a renovation in the early nineteenth century with sash that had a narrower muntin, similar to those originally used in Stoughton Hall. Information on the size and profile of this later muntin was available both in HABS documentation for Hollis and in a single surviving example of the Stoughton muntin, which was on display in the dormitory. The design of the muntins, which was based on the archival evidence, and several variations to accommodate the thicker glass were reviewed and revised with the input of both window manufacturers—to ensure strength and durability—and the Cambridge Historical Commission—to ensure historical appropriateness. Eventually, a slightly narrower and much deeper muntin was selected to accommodate the insulating glass and the durability performance requirements.
Detail drawings of the sash show construction of the wood glazing stop that holds the insulating glass and the different waterproofing details between the wood window frame and masonry. At Hollis and Stoughton, both pieces of glass in the insulating units are standard float glass. While restoration glass would have been more appropriate, the University decided that the smaller lites in these sash would not reveal the irregularity in the more expensive glass.
MATCHING NEW BITS WITH OLD
Paint was stripped from the existing frame material and soft spots and checks were repaired with epoxy consolidants and fillers. Dutchmen for portions of several sills and dozens of blindstops were milled from white pine and mahogany before they were fitted to the frames. To ensure that the repair would be durable, the dutchmen were custom cut to fit the straight and square rabbets and mortises that the mechanics from Colony Architectural, the window subcontractor, had pared out of the jagged edges of the damaged frames. Colony's mechanics used galvanized nails and waterproof glue to secure the dutchmen. Once the frame repair was done, they hung the new mahogany sash using brass pulleys, locks, and lifts and copper sash chains.
LOOKING OUT ON THE YARD
After more than a year of service, the restored and renovated dorms have been well received by students and the University. The historically accurate paint palettes on the window frames and the substantial wood sash have brought a rich variety of architectural detail back to the Yard and have met, or exceeded, the University's performance expectations. In the end, it seems the thoughtful debate about windows and the cooperative working relationships developed during the project have left Harvard with a physical plant that matches its academic reputation.
Technical information for this article was supplied by Judith Selwyn, John Clancy, Susan Pranger, and Seth Ravitz.
Project: Hollis, Stoughton, and Weld Halls, Harvard University, Cambridge, MA
Owner: President & Fellows of Harvard College
Client: Weld: Harvard Real Estate (Peter Riley, proj. manager). Hollis & Stoughton: Faculty of Arts & Sciences (Alana Knuff, proj. manager)
Architect: Goody Clancy & Associates, Boston, MA (John Clancy, partner-in-charge; Susan Pranger, proj. manager; James Norris, Victor Ortale, Randi Holland, and Martin Deluga, proj. architects)
Architecturol Conservation: Preservation Technology Associates (Judith Selwyn, principal; William Finch, associate)
Contractor, Weld Hall: Beacon Construction (Seth Ravitz, proj. manager)
Contractor, Hollis Hall: Shawmut Design & Const. (Michele Murphy, proj. manager) Painting Subcontractor, Weld Hall: Soep Painting Corporation
Window Controctor: Colony Architectural. Cost: Weld, $5m; Hollis & Stoughton $5.4m
Building Materials: Slate, Weld: Buckingham Slate. Slate, Hollis & Stoughton: Pethryn Purple (Wales). Copper: Revere Copper Products. PVC membrane: Sarnalil. Windows, Weld: Architectural Components. Windows, Hollis & Stoughton: KSD Custom Windows. Glass (Weld Hall, only): SA Bendheim. Windows, Hollis & Stoughton: KSD Custom Wood Products. Paint, exterior: Hancock and Conlux. Paint, interior, Benjamin Moore. Epoxy consolidants and lillers: Abatron.
Photos: PTA, unless otherwise noted.
Contractor (Weld Hall)
Contractor (Hollis and Stoughton Halls)
Aluminum combination storm sash and screens had been installed to improve thermal performance and security, but had not proven durable. Leaky roofs had caused wood trim to rot and paint to peel.
Deferring maintenance had caused nearly universal failure of the paint film. As a consequence, much of the wood trim was showing signs of decay.
The existing sash at Weld were a mix of original sash and replacements from a 1960s renovation. Because thermal performance and durability were important factors affecting the window work, the preservation consultant felt that the original sash could be replaced without affecting the building's historic or architectural value.
Because the original window frames had been built into the load-bearing brick walls and had survived more than a century of harsh New England weather largely intact, the preservation consultants recommended that the frames be repoired in situ. This jamb is shown stripped of point.
Because the project was on a particularly tight schedule, the years of point accumulation on the dormers and window frames could not be chemically or mechanically stripped. Therefore, the pointing subcontractor, Soep Painting Corporation, thoroughly scraped the existing finishes.
PTA and Goody Clancy requested that mockups of the work on each window be reviewed before work could continue. To expedite the approval, a phased finishing schedule was adopted. When the scraping and conservation were completed, two-thirds of the window was primed and half of the primed area was painted with a coat of the finish. The consultants were then coiled and all the prep and finish work approved in one visit. Once standards were established, work followed a more normal schedule and was reviewed periodically.
Replacing the original Monson, Maine black slate roof with Buckingham slate required careful attention to details. The thickness of the replacement slates was 1/8-inch greater than the original 1/4-inch thick material. While the decision to use thicker slate will benefit the school in the long-haul, it required rethinking the flashing and trim details around each dormer. The roofing contractor, for example, was required to provide mock-ups of flashing details such as this soldered cap that fits over the sill.
Copper was selected as a flashing material over lead-coated copper because PTA had found that lead-coated copper often suffered from galvanic corrosion at pinholes in the lead coating.
Paint analysis revealed the original paint scheme: black sash, rudely brown window frames and architraves that trimmed the dormer windows. But, as is often the case when original paint schemes are recreated, neither the client nor the architect found these colors satisfactory in the overall context of the Yard. In an attempt to appease all, Goody Clancy had five mock-ups prepared using colors that were slight variations on the original and were considered appropriate for the period. The scheme that was eventually selected, with input from the architect, preservation consultant, University, and Historical Commission, called for black sash and brandywine frames and trim.
The new sash, only one among many new finishes used in this project, provide a smooth transition from the restored exterior to the finely detailed contemporary interior.
The Yard has long been the essential element of Harvard's public image. The false muntins on replacement windows did not do much to support this image; frequently broken or missing, they made the windows look cheap and the Yard disheveled. Worse, the sash did not operate, fit properly, and were a nightmare to maintain.
Integral mouldings and blindstops in the original wood frames, which were built-up from solid lengths of 3 x 5 inch white pine, were torn off when aluminum replacement windows were installed in the 1960s. Many sills had been hacked off to accommodate the sill panel of the aluminum units. This damage was repaired as part of the current work.
Because the frames had been built into the surrounding load-bearing brickwork, conservation and repair of the remaining sections of the frame had to be carried out in situ. The window subcontractor, Colony Architectural, Inc., consolidated the less than solid portions of each frame and squared-up and straightened sections that had been torn apart in the earlier restoration before fitting dutchmen. Holes, checks, and other damaged areas left after the dutchmen had been set were filled with an epoxy compound.
When painted with one coat of prime and two coats of gloss alkyd finish, the new sash and repaired frames looked as good as new. Each of the lower sash is fitted with copper sash chain and brass locking hardware. By specifying that the upper sash in each window be fixed, the architects were able to eliminate the initial cost of one pair of pulleys, counterweights, and sash chain and the on-going costs of maintaining two operating sash, as well as improve the thermal efficiency of the window assembly.
The new sash complement the restored interior finishes. The wainscotting, which dates from a renovation in the late nineteenth century, was turned insideout when TAC modernized the buildings in the 1960s. Goody Clancy had wanted to turn these wide boards right-side-out, but concern for the hazards of removing many layers of lead-based paint prevented them from doing so.