Adaptive Reuse of a Coral-Rag Warehouse Inside Galle Fort
A client has bought a 19th-century coral-and-lime-mortar warehouse inside Galle Fort, a UNESCO World Heritage property, and wants it converted into a 20-room boutique hotel within 14 months for LKR 180 million. The building is 42 m long by 11 m wide, with 600 mm coral rag walls, a king-post timber roof that is 40% collapsed, no damp-proof course, and a floor 300 mm below street level. The architect's measured survey records a 40 mm outward lean over 3 m at the north gable, and the lime plaster is salt-contaminated to 1.2 m above floor level. The client's brief includes a reinforced concrete mezzanine, eight new openings cut into the street elevation for room windows, and a 60-cover rooftop restaurant. Consent is required from the Galle Heritage Foundation, the Department of Archaeology and the municipal council. The client argues that adaptive reuse means the building must earn its keep, and that strict heritage conditions will make the project unviable.
1. The client's three interventions - the RC mezzanine, the eight new street openings and the rooftop restaurant - are not equally defensible. Assess each against conservation principles and state what you would recommend, with reasons.
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Apply the tests the approvals bodies will actually use: minimal intervention, retention of significant fabric, reversibility, distinguishability of new work, material compatibility, and authenticity of form, substance and setting.
RC mezzanine. Weakest on compatibility. A rigid RC frame needs new pad foundations and dowels into coral rag; both are irreversible. Propose instead an independent steel or glazed-timber frame carried on isolated pads set in reversible pockets, or a mezzanine that spans wall to wall without touching historic faces.
Eight street openings. Cutting coral rag destroys the substance that carries the property's Outstanding Universal Value, and the street elevation rhythm is part of that value. Recommend retaining the existing openings, using internal glazed screens and light wells to bring daylight deeper, and, if a new opening is truly unavoidable, restricting it to a rear or internal elevation after full photogrammetric recording.
Rooftop restaurant. The decisive issue is the skyline seen from the ramparts, the key view. A 60-cover volume above the parapet is visible and therefore conflicts. Recommend locating the restaurant within the ground-floor volume, or a set-back, lightweight, clearly distinguishable structure that does not break the parapet line.
Then answer the viability argument with a costed alternative scheme rather than trading fabric, and confirm the statutory basis: Antiquities Ordinance approval plus the Foundation's heritage guidelines.
2. The 40 mm lean at the north gable must be resolved before design development. Set out your investigation sequence and state what you would not do in the first three months.
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The first question is not how to correct the lean but whether it is historic and stable or progressive. Many walls in Galle lean; correcting one that has been stable for a century is itself an intervention.
Sequence:
- Documentary baseline - search the Foundation's archive, old photographs, previous measured surveys and any earlier repair records to date the lean.
- Condition mapping - draw every crack, record width and orientation, note previous cement pointing and its role as a hard, brittle repair.
- Monitoring - plumb survey to a fixed datum, tell-tales across cracks, total-station readings of the gable and the roof structure, monthly for at least one full wet and dry cycle.
- Cause analysis - inspect the roof for rafter spread and thrust on the gable, check gutters and downpipes, check ground levels and drainage on the street side, and confirm with a hand auger whether soft or wet material sits at the toe.
- Only then commission any structural analysis.
What I would not do: prop, grout, underpin, or strip the salt-contaminated plaster before baseline monitoring, because each destroys the evidence and may accelerate the problem. I would also not introduce cement-based mortar anywhere, since it traps salts and concentrates decay in the coral rag.
3. Draft the substance of the conservation statement you would submit to the Foundation and the Department of Archaeology. What evidence must it contain?
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A submission that argues only aesthetics will be refused; the statement must work as an evidence-based impact assessment.
Structure it as:
- Statement of significance - why the building matters, its attributes, and its contribution to the Fort's Outstanding Universal Value, with the specific views and elevations that carry that value.
- Condition survey - measured drawings, crack mapping, salt and moisture readings, the monitoring data and its conclusion on whether the gable lean is active.
- Impact assessment, intervention by intervention - for each of the mezzanine, openings and rooftop volume: fabric lost, reversibility, material compatibility, visual impact on the key view, and residual risk after mitigation.
- Alternatives considered - show the option that avoided cutting the street elevation, with the cost and programme difference. Approvals bodies respond to evidence that alternatives were genuinely tested, not to a claim that the client cannot afford compliance.
- Method statements - lime mortars and renders matched to the original, salt extraction and desalination, roof repair in traditional timber, fixing details that avoid chasing historic faces.
- Recording and archiving - photogrammetry before any intervention, with copies lodged with the Foundation.
- Monitoring and maintenance plan - a schedule the hotel operator will actually fund and follow.
Attach the statutory consent applications and the structural engineer's statement reporting the monitoring conclusion.