Reuse project

The final weeks of the term are given to the reuse project itself. Each student prepares a complete proposal for the Stanfield's rehabilitation, and the class reviews them together before presenting a single scheme, built on Callum's, to Greenway Homes' board and to the city's heritage preservation staff. Bérubé sets out what the proposal must contain: a statement of significance, a conservation approach for every character-defining element, the design drawings, a code strategy, a carbon comparison, a cost and funding plan and a heritage impact assessment. 'Everything you have learned this term goes into one document,' she says. 'If a reviewer opens it at any page, they should be able to see what you are keeping, why, and what you are changing, and why that change is worth what it costs.'

The brief

Greenway Homes' brief, refined over the term, asks for forty-six homes, a third of them at rents below market, with at least eight designed as live-work units for artists; a public gallery and a community print studio on the ground floor, run by a local arts organization; a lobby, bicycle storage, laundry and a shared common room; and a building that will be comfortable, accessible, safe and affordable to run for at least another century. The owner's option on the building expires in the spring, so the proposal must persuade Greenway's board that the project is worth buying, the heritage reviewers that it respects the building, and the funders that it can be built.

Statement of significance

The proposal opens with the statement of significance the students revised after their archival research and condition survey. The Stanfield Warehouse, completed in 1911 and a contributing building of the Minneapolis Warehouse Historic District, is valued for its association with the wholesale trade that shaped the district; as a largely intact example of mill construction, with brick bearing walls, heavy timber posts and beams on cast-iron caps and nail-laminated plank floors; for its restrained commercial facade of red brick with segmental-arched openings, a stone base and sills and a pressed-metal cornice; for its open, column-filled interiors lit from the ends; for its painted sign and its place in the continuous wall of warehouses along the avenue; and for its later history as a printing works and as artists' studios, including the 1930s mezzanine with the building's only surviving decorative woodwork. Its character-defining elements are listed in a table keyed to the drawings.

The design

Callum's scheme, refined by the class, keeps the building's structure, envelope and principal spaces and inserts the new use with as few large interventions as possible. On the ground floor, the 1960s aluminum storefront is removed and replaced by new wood and glass storefronts based on the photographs of 1912, with a step-free entrance in one bay where the floor is lowered inside the new storefront. The gallery occupies the front half of the floor under the restored timber ceiling, lit from the avenue and from a skylight at the base of the light court; the print studio occupies the back half, opening onto the lane through the restored loading dock, where presses can be delivered and where the studio's work can spill out in good weather. The lobby, mailroom and elevator are placed beside the original stair.

On the four upper floors, a corridor along the central line of posts serves ten homes per floor, arranged on the avenue and lane facades, along the exposed east wall with its new windows and around three sides of the light court. Each home contains at least one whole bay of the timber frame, with its post and beam exposed and its plank ceiling visible. Bathrooms and kitchens are grouped around plumbing shafts placed between beams. The 1930s mezzanine on the third floor becomes the shared common room, reached by a short new bridge from the corridor and furnished with tables made from the timber salvaged from the light court. The one-story rooftop addition, set back 20 ft from the avenue parapet and 10 ft from the lane, holds six homes with terraces, clad in dark standing-seam metal and carried on independent steel columns down to new footings.

Conservation approach, element by element

For each character-defining element, the proposal states the treatment and the method, drawing on the earlier lessons. The brick walls are preserved and repaired: cleaned gently with low-pressure water where soiling traps moisture, repointed only where joints are eroded, with a lime mortar matched by analysis, and with failed bricks replaced by salvaged ones from the new east-wall openings. The parapet's worst section is rebuilt with salvaged brick and a new sloped cap and flashing. The stone base and sills are repaired with lime-based repair mortar, dutchmen and new stone from the original quarry where delamination is severe. The pressed-metal cornice is repaired in place and its missing sections replicated from the surviving profiles and the 1912 photographs, marked as new work. The original windows are repaired, reglazed, weatherstripped and fitted with interior storms; the few beyond repair, and the bricked-up bay, receive new wood windows matching the original pattern. The painted sign is cleaned and consolidated, not repainted.

Inside, the posts, caps, beams and plank floors are preserved and left exposed. The beam ends at the fifth floor are spliced and the wall pockets repaired once the roof has been made watertight. The floors are leveled with the acoustic topping rather than by jacking. The original stair is kept as an exit, enclosed in a rated shaft with a glazed wall to the corridor and given a supplementary guard. The freight elevator's shaft becomes the service riser, with its gate and hoisting machinery kept on display in the lobby. The mezzanine's woodwork is cleaned and repaired. Elements without significance, the 1960s storefront, the acoustic tile ceiling, the concrete-block basement wall and the iron fire escape, are recorded and removed.

Code strategy and performance

The code strategy follows Lesson 9. The project is a Level 3 alteration with a change of occupancy under the existing building code, and the team uses the historic buildings provisions where needed. The building is fully sprinklered and alarmed. Homes are separated from each other and from the corridor by rated construction; the timber frame remains exposed, with its fire resistance confirmed by char calculation and the plank floors rated with the topping. Two exits serve every floor: the original stair, accepted on the basis of the sprinklers, its enclosure and a new second stair of full code geometry; and the new stair against the east wall. A step-free entrance, an elevator to every floor and accessible units distributed through the building meet the accessibility requirements, with alternative minimum requirements used only where full compliance would harm historic significance. The roof is insulated heavily, the windows are repaired and stormed, air leakage is sealed, and modest vapor-open interior insulation is added on the lane and party walls after hygrothermal modeling confirms the brick will tolerate it. Each home has its own heat pump and heat recovery ventilator.

The carbon comparison from Lesson 10 is updated with the final design, after the changes the students made to reduce the carbon of the addition, the topping and the windows. It shows the conversion's upfront carbon at less than a third of the demolish-and-replace option, and a payback for the new building that is measured in decades on a fossil-heavy grid and centuries or more on a clean one.

Cost and funding

Ben Okafor, the cost estimator who priced the students' Design Studio V project, prepares an estimate for the conversion. Old buildings are expensive to estimate because of their uncertainties, so he carries a larger contingency than for new work, about 15% of construction cost, and he prices the conservation work, the masonry, windows, cornice and timber repairs, separately from the general construction so that it can be tracked. The total cost, including acquisition, design, construction, contingency and financing, is about 25.2 million dollars. The students then assemble the funding.

# Funding plan for the Stanfield conversion (dollars)
cost = {
    "acquisition": 2_600_000, "construction (incl. 15% contingency)": 19_300_000,
    "design, permits, testing": 1_900_000, "financing and soft costs": 1_400_000,
}
total = sum(cost.values())
qre = 17_800_000                      # qualified rehabilitation expenditures
federal = 0.20 * qre                  # federal historic tax credit, claimed over 5 years
state = 0.20 * qre                    # state credit, assumed at the same rate for this plan
price = 0.85                          # equity raised per dollar of credit (assumed)
sources = {
    "first mortgage": 12_300_000,
    "federal historic credit equity": federal * price,
    "state historic credit equity": state * price,
    "city and state affordable housing funds": 4_300_000,
    "Greenway Homes equity and fundraising": 2_200_000,
}
have = sum(sources.values())
print(f"total cost {total:,}")
for k, v in sources.items():
    print(f"  {k:<40} {v:>12,.0f}  {v / total:5.1%}")
print(f"funded {have:,.0f}; gap {total - have:,.0f}")

total cost 25,200,000
  first mortgage                             12,300,000  48.8%
  federal historic credit equity              3,026,000  12.0%
  state historic credit equity                3,026,000  12.0%
  city and state affordable housing funds     4,300,000  17.1%
  Greenway Homes equity and fundraising       2,200,000   8.7%
funded 24,852,000; gap 348,000

The plan leaves a gap of a few hundred thousand dollars, which is typical at this stage and which the students propose to close with value engineering that does not touch the conservation work, and with a fundraising campaign for the gallery and print studio. Okafor points out that the historic tax credits provide about a quarter of the project's funding, which is why the design has been tested against the Standards for Rehabilitation from its first sketch: a single element that fails certification, such as replacing repairable windows or a visible rooftop addition, could cost the project millions of dollars of equity. The heritage of the building, through the credits, helps to pay for its own conservation.

The heritage impact assessment

The final document in the proposal is a heritage impact assessment, which describes each proposed change, the character-defining elements it affects, the impact on the building's heritage value, and the measures taken to avoid, reduce or offset it. Bérubé insists that it be honest. A heritage impact assessment that finds no impact anywhere is not believed by anyone. The students rate each intervention on a simple scale and record the mitigation.

# Heritage impact assessment summary for the Stanfield proposal
# impact: 0 none, 1 minor, 2 moderate, 3 major (after mitigation)
items = [
    ("new storefronts based on 1912 photographs", "storefront (non-defining)", 0, "replaces 1960s work; restores lost character"),
    ("new windows in the east wall", "secondary elevation, sign", 1, "simple openings on the bay rhythm; sign panel untouched"),
    ("light court of two bays", "timber floors, open plan", 2, "smallest workable court, central, timber salvaged and reused"),
    ("partitions for homes", "open floors", 2, "walls on bay lines, posts free in corridor, ceilings open"),
    ("acoustic topping over planks", "plank floors", 1, "planks stay visible from below; reversible"),
    ("rooftop addition", "roofline, cornice, setting", 1, "one level, set back, recessive, hidden from the avenue"),
    ("original stair enclosed", "stair", 1, "glazed wall keeps it visible; supplementary guard"),
    ("fire escape removed", "fire escape", 1, "recorded; no longer functional"),
    ("cornice sections replicated", "cornice", 0, "on firm evidence; new work marked"),
]
labels = ["none", "minor", "moderate", "major"]
for what, affects, score, mitigation in items:
    print(f"{what:<42} {labels[score]:<9} {mitigation}")
print("\nhighest impacts:", "; ".join(w for w, a, s, m in items if s == max(i[2] for i in items)))
print("average impact:", round(sum(i[2] for i in items) / len(items), 2))

new storefronts based on 1912 photographs  none      replaces 1960s work; restores lost character
new windows in the east wall               minor     simple openings on the bay rhythm; sign panel untouched
light court of two bays                    moderate  smallest workable court, central, timber salvaged and reused
partitions for homes                       moderate  walls on bay lines, posts free in corridor, ceilings open
acoustic topping over planks               minor     planks stay visible from below; reversible
rooftop addition                           minor     one level, set back, recessive, hidden from the avenue
original stair enclosed                    minor     glazed wall keeps it visible; supplementary guard
fire escape removed                        minor     recorded; no longer functional
cornice sections replicated                none      on firm evidence; new work marked

highest impacts: light court of two bays; partitions for homes
average impact: 1.0

The assessment identifies the light court and the partitions as the two moderate impacts. Both affect the open, column-filled floors, the most fragile element of the building's character, and both are needed for the building to become homes. The proposal argues that they are acceptable because they are as small as the use allows, because the structure remains fully legible, because the removed timber stays in the building and because, without a use, the building would continue to decay. It acknowledges that an office or studio use would have kept the floors more intact, and records that Greenway chose housing because it serves the community's greatest need. This honesty, Bérubé says, is what makes a heritage impact assessment persuasive.

The review

The students present the proposal to a panel of reviewers in the gallery space of the Stanfield itself, under work lights strung from the beams. Gagnon and the chair of the heritage preservation commission review the conservation approach. Kostyshyn reviews the code strategy. Szymańska and Mensah review the structure and services. Takahashi reviews the carbon. Okafor reviews the budget. Two members of Greenway's board and the director of the arts organization that will run the print studio ask what they will be buying. Tomas Okonkwo, the critic who has reviewed the students' studio work since their second year, reviews the architecture.

The questions are pointed. Gagnon asks whether the light court could move one bay toward the lane, where it would remove timber that was replaced after the 1938 fire rather than original timber. The students had not considered it; they agree to test it, and the change turns out to work. Kostyshyn asks how the residents of the fifth floor will escape if the original stair is blocked, and the students show the travel distances to the new stair. Takahashi asks whether the heat pumps' refrigerant has been counted, and it has. A board member asks whether the homes will feel dark, and Ingrid shows the daylight studies of the units around the light court, which meet the targets except in two homes, which the students convert into live-work studios with a larger share of their area at the windows. Okonkwo asks the last question: what in the design would a visitor in fifty years recognize as belonging to our time? Callum points to the addition, the new storefronts, the east-wall windows and the light court, each clearly new and each clearly subordinate to the warehouse. 'Good,' says Okonkwo. 'Then the building will tell the truth about itself.'

What the course has taught

On the last day, Bérubé asks the students to answer, one more time, the question she asked in the first week: why should anyone keep this building? Their answers are longer now and more precise. The Stanfield should be kept because it is evidence of the trade that built the district and of the way buildings were made in 1911; because its open floors and robust frame are good at being reused, as they have been reused before; because its brick and timber hold carbon that would be released and lost if it were demolished; because it makes the street what it is; and because the people who know it, from the retired printer to the artists of the fifth floor, value it. They also know now what keeping it costs and how to keep it well: understand it first, change it as little as the new use requires, repair before replacing, make new work honest and subordinate, and record everything. The building is still empty, but Greenway Homes' board votes the following week to exercise its option and buy it.

Exercise 12: the reuse proposal

• Prepare a complete reuse proposal for a historic building of your choice, with a statement of significance, conservation approach, design, code strategy, carbon comparison, funding plan and heritage impact assessment.
• Present it to a panel and record the reviewers' questions and your responses.
• Revise the proposal in response to one review comment and explain how the change affects each part of the proposal.
• Write a short reflection on the conflicts between conservation, use, cost and carbon in your proposal, and how you resolved them.

Self-check

• Can a reviewer find, on any page, what is kept, what is changed and why?
• Is each intervention justified by the new use and as small as it can be?
• Is the heritage impact assessment honest about the impacts that remain?
• Have I shown that the project can be built and paid for?