The Global Standard for Conserving Historic Plaster
Historic Plaster Conservation Services (HPCS) was founded in 1988 to pursue opportunities in the very specific field of architectural plaster conservation. We address and repair the structural problems of fragile plaster in historic buildings.
Over the years, we have developed and patented an array of specialty products, techniques and tools, designed to strengthen and re-attach existing plaster on ceilings and walls. We address the problem at its root – where the plaster meets its substrate.

Our specialty products and techniques are effective on the most elaborately embellished plaster and on the simplest plain face vernacular plaster. Traditional lime plaster on wood lath, cementitious plaster on expanded metal lath, plaster on masonry and even cast fibrous plaster suspended ceilings respond well to our conservation treatment programs.
Consolidating and Securing Failing Plaster in Historic Buildings
We specialize in addressing the systemic deterioration of plaster. Applied as a preventive maintenance procedure, our products economically extend the safe and maintenance-free service life of historic plaster ceilings – avoiding the tragedy of collapse and the huge expense of reconstruction. In short, we preserve original plaster.
Leading preservation architects and heritage consultants specify the HPCS approach in restorations where important plaster is at risk.
Our goal is to work with clients who value the original building fabric for which they are responsible and who wish to retain this fabric with the lowest possible level of disruption and cost.
Featured Projects
BILLINGS ESTATE NATIONAL HISTORIC SITE
Ottawa, Ontario (1829) The Building:The Billings Estate is one of Ottawa’s earliest homes. It was built by Braddish Billings in the late 1820s and was occupied by the Billings family until 1975. In 1968, the house was designated a National Historic Site. The site is primarily known for its landscape and exterior features. Many of the earliest interior finishes have been lost or are covered, but much of the original or early plaster remains. The City of Ottawa operates the site as a historic house museum. Project Synopsis:In 2024, the City retained HPCS to assess the condition of two plaster…