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Conserving Nova Scotia’s Heritage Wood Windows

popularity. Today, there are only a few sash-making shops left in the province. The survival of these shops depends on a niche market fueled by individuals who have a balanced view of heritage and sustainability; and who re-introduce back into design thinking the importance of durability, repairability and the value of our intangible cultural heritage.

Austin Parsons, Assistant Professor School of Architecture Dalhousie University Building Technology Group, Building Culture and Conservation Program Owner, Parsons Lumber Company Limited


Introduction A heritage wood window includes a pair of vertically sliding, single pane, true divided light sashes and a window box assembly made up of a sloping sill, jamb, casing and back band. The window is made from air-dried eastern pine, glass, glazer’s putty, nails and glazer’s points. It is the type of window one would still see today in a period home or in a light commercial building that went through rehabilitation, e.g. a restaurant or museum. History

Parks Canada’s Standards and Guidelines for the Conservation of Historic Places in Canada (2010) name three conservation interventions: 1) Preservation – to maintain and/or stabilize 2) Rehabilitation – to accurately restore elements 3) Restoration – to promote a continuing or compatible contemporary use Their 14 general standards for preservation, rehabilitation and restoration include: • minimal intervention (Standard 3) • reversibility (Standard 12) • repair rather than replace in-kind (Standards 10 & 13)

Heritage wood windows are made by sash makers. The sash-making trade began with the invention of the hung window in the late seventeenth century. This knowledge came to Nova Scotia with the Planters and Loyalists via New England.


As Nova Scotia was settled, people learned the trade through the time-honoured apprenticeship system. Sash-making shops opened in every community, making sashes in different styles

A1. Yes. You can use a site-built window, door and skylight if it doesn’t conform to the harmonized standard National Building Code (2010) Sections 9.7.5, 9.6, 9.7.5 and 9.7.6.

In the twentieth century, Modernity and the energy crisis both affected the heritage wood window’s

Q1. Can I use a heritage wood window built by a custom manufacturer in a new build or a renovation even if it doesn’t conform to the harmonized standard, i.e. NAFS, the North

Q2. Can I use a single pane, true divided light, wood window even if doesn’t meet the Nova Scotia energy standards? A2. Yes. page 2

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Code (continued) 1) Heritage building: The 2010 energy code doesn’t apply to a heritage designated building (Nova Scotia Building Regulations [2011] Section (2)). 2) Non-heritage designated building: Include a storm window as part of the installation (Section Thermal Resistance of Windows in the Nova Scotia Building Regulations [2011] takes precedent over Section Thermal Characteristics of Windows, Doors and Skylights of the National Building Code 2010). Sustainability one most germane to a heritage wood window is its time-tested design made from local materials with a time-honoured craft knowledge. Employing mortise and tenon connections and functional joinery, the window parts are pinned together but not glued so that they can be removed and replaced or repaired as required. Its life cycle is long because it is durable and repairable. Design A heritage wood window performs as a system. Its deliberate construction sequence means that a heritage wood window sheds water via a series With the addition of a storm window, it is designed to control capillary action, surface tension, momentum, gravity and pressure differential. page 4

Technology Four over two square and round top window front elevations and section.

Material palette – air-dried eastern white pine, nails, glass, glazier’s putty and glazier’s points, 4 lb cut shellac, primer, paint, weather strip, window hardware and a storm window

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Austin Parsons


t. 902-233-3431 s. 902-858-3431 e.


houdinidesign June, 4 2013



Conserving Nova Scotia’s Heritage Wood Windows

Parsons Lumber  
Parsons Lumber