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According to the World Green Building Council, buildings are the main source of greenhouse gas emissions, accounting for approximately 40% of greenhouse gas emissions. We know that adapting and reusing existing buildings, whether heritage or not, is vital in order to combat climate change. Adaptive reuse of existing structures, including significant changes with minimal intervention, has always been a key objective for heritage architects and consultants. As a heritage consultant, I believe that the design and technical decisions that go into preserving a building are as important as the long-term environmental impact of the building.
Being educated as an architect in Cuba, a country with limited resources, taught me the importance of creatively repurposing buildings. In Cuba, my work spans institutional, residential, commercial and religious projects. In my work as principal and heritage specialist at GBCA Architects in Canada, I draw on my experience in Canada and Cuba to conserve a variety of buildings – some with national landmark status, such as Massey Concert Hall and the Mackenzie Hall in Toronto The concert hall is in Windsor, some are just old buildings.
Architects, particularly heritage architects and their consultants, have a responsibility to advocate for accountability throughout the process. However, there are several obstacles that make the above key goals difficult to achieve. Some obstacles are technical and some are not.
Non-technical obstacles include legislative challenges and misconceptions that Canadian heritage is “not old enough” and that “heritage is expensive.” Let me address these issues.
A major obstacle is the misconception that preserving heritage is expensive. I believe that part of my role when advocating for the conservation of buildings is to help clients understand the economic benefits of heritage conservation strategies.
Reusing existing materials and components can save money by reducing construction time and the time and labor costs associated with demolition. Add to this the costs of removal of materials, disposal of materials, demolition which may sometimes require street closures and traffic, and the overall financial picture can be considerable.
Clients are encouraged to see that preserving existing buildings not only saves money by reducing construction time and avoiding demolition costs, but also demonstrates goodwill towards our heritage and a commitment to reducing carbon emissions. Thankfully, these non-monetary issues are increasingly important to today’s building end-users. Customers, including some developers, responded positively.
For example, GBCA was hired to renovate a late 19th century building (circa 1893) in Toronto’s west end. The goal is to enhance the site for new rental residential units. The building is not designated or registered and is simply an “old building” typical of the community. It is part of a congested community, located on a busy traffic line, with many site constraints and challenging heritage assembly.
Our first approach is to assemble a team of consultants experienced in heritage work.
We were able to show our clients that they could save money by reusing existing bricks and other materials, thereby reducing demolition deliveries without requiring road closures or special permits, or the use of expensive cranes.
The use of new materials is limited to reinforcement requirements and some compartments and interior decoration. Key to the project was the ingenuity of specification consultant Allan Larden, who provided a wealth of technical rationale for the staircase’s reuse. They wrap around the elevator and therefore do not meet “current codes”. Paradoxically, he proposed an acceptable upgrade so that the stairs could be retained and used as another means of egress, thereby meeting the Ontario Building Code.
Thanks to the creativity of the entire team, we were able to reuse approximately 80% of the structure.
Technical barriers to adaptive reuse Weaknesses in existing structures include a lack of research-backed data (fire ratings, engineering properties, etc.) and a lack of knowledge about historic materials and their combinations, especially among non-heritage trained consultants. And, as noted above, the estate is dismissed as not complying with “current norms” without creatively evaluating the opportunity.
Despite this long history, we still don’t have many reliable sources about the materials and methods used in Canadian construction in the past. Due to a lack of data, it is difficult to demonstrate an evidence-based rationale for preserving materials and/or integrating heritage with current building code requirements.
As heritage consultants we promote the reuse of existing materials and components by demonstrating how historic materials and wall components work. For example, weak wall components such as clamp-bonded (also known as hidden joints) can still be reused. GBCA did just that in a recent adaptive reuse project (see below). This is another heritage-related success due to teamwork and our in-depth understanding of heritage construction techniques and assembly systems.
To achieve this success, we worked with Montgomery Sisam Architects, LEA Consulting Engineers and Clifford Restoration on the Toronto Catholic District School Board’s conversion of a religious building into a new school at the former Scarborough Foreign Mission. Project cooperation. We retained much of the structure and avoided expensive and environmentally unfriendly retention systems.
A study of historical photographs provided valuable insight into the construction methods of the 1923 building’s terracotta tiles, steel columns and steel structure. Armed with this knowledge, the design team considered three options.
One option is to completely eliminate traditional elements by introducing a facade retention option, which is also not environmentally friendly. Another option would require full reinforcement but retain historical elements, but would negatively impact progress and raise environmental concerns.
The third option is a hybrid approach: reusing existing elements in a carefully planned construction/demolition sequence “from top to bottom.” We chose the third option.
By adopting a “top-down” construction/demolition approach, we were able to reuse existing steel beams along with the new concrete deck, avoiding more destructive methods and mitigating environmental impact. We also reused existing clay bricks in each floor as new concrete forms and recycled and reused the proposed supports in each floor. I used this method successfully in Cuba about 20 years ago, converting a 1920s convent into a hotel.
Teamwork and knowledge help overcome our obstacles. Consultants are vital to heritage architects and as we all know, they can be friends or foes of project strategy.
In addition, our industry can make more progress by solving the following problems Barriers from our own lack of technical knowledge About heritage buildings. Our education system needs to incorporate more heritage-related content to cover the science and pathology of heritage building. This will help build a community of professional consultants who can provide practical solutions that combine existing building components with current building regulations. This is particularly important as Canada’s inner-city buildings age and the need for skilled consultants for heritage work increases.
In summary, reusing existing buildings can bring significant social, environmental and economic benefits. To achieve this, I encourage architects and relevant consultants to engage heritage professionals early on in their projects and enhance their technical understanding of heritage practice. Incorporating these practices into educational programs across a variety of built environment disciplines will promote a more holistic approach to architectural conservation and sustainability.
Carlos Morell has 30 years of experience in conservation and historic preservation. He trained as an architect at the University of Havana, Cuba, and studied cultural heritage conservation and restoration before moving to Canada. He started working at GBCA Architects in 2007 and is currently responsible for all technical aspects including drawings, specifications, masonry restoration, building envelope analysis, integration of new technologies into heritage buildings and contract administration.
Carlos is a principal at GBCA Architects in Toronto and has worked on the design of heritage buildings such as Fort York, Union Station, Ontario Legislative Assembly, Mackenzie Hall (Windsor) and Massey Concert Hall.
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