An Architect's Guide for Sustainable Design of Office Buildings
1. Sustainability
A New Agenda for Building Design
1.0 Introduction
Following the publication of the Brundtland Commission's report, Our Common Future,[1] sustainability has emerged as a widely held and necessary notion to guide all future human endeavours. Although sustainability is, and will remain, a difficult notion to define in substantive terms, the implications are clear. Sustainability will require that we become less wasteful of natural and human resources, take appropriate steps to maintain a healthy, productive planet and place greater worth on the welfare of future generations.[2]
Sustainability has social, economic and environmental dimensions. Environmental sustainability implies that future generations should enjoy continued access to resources. However, it is the total capital, both natural and physical, passed on to future generations that is of primary consequence.[3] Since buildings result from the transformation of both renewable and non-renewable natural assets, building design and construction can make a significant contribution to the sustainability debate.[4]
1.0.1 Renewable Resources
Discussion of renewable resource use is only meaningful when set against the biological limits and production capabilities of the biosphere. The continued degradation of the biosphere through over-exploitation and abuse diminishes its ability to produce essential resources but also its ability to recover from such abuses. A prerequisite for sustainability is the maintenance of the functional integrity of the ecosphere so that it can remain resilient to human induced stresses and remain biologically productive. Sustainability will require that the generation of waste and pollution from human activity, including the construction and operation of buildings, be kept within the assimilative capabilities of natural systems.
1.0.2 Non-Renewable Resources
Non-renewable resources, as finite assets, must be used or transformed such that they remain useful and accessible to future generations. Therefore, in addition to reducing the amount of resources invested in them, buildings must become useful assets for future generations. The implications on the quality, longevity and reusability of buildings and the recoverability, reuse and recyclability of their constituent materials and components will be profound.
1.1 Federal Environmental Policy Framework
Since the release of the Green Plan in 1990, and of the Federal Code of Environmental Stewardship in 1991, environmental requirements have increased significantly for all federal departments. The Green Plan sunset in 1996, to be replaced by a government-wide strategic plan, the Federal Sustainable Development Strategy. Environmental requirements will continue to increase as will reporting requirements to central/regulatory agencies, Parliament and the public. Through amendments to the Auditor General Act on December 15, 1995, all federal departments are required to prepare a Sustainable Development Strategy (SDS) with concrete goals, objectives and action plans, to be tabled in Parliament by December 1997.
The general intent of the strategy is to provide the departments with the framework to integrate environmental considerations in the management of their activities. This is to be achieved by adopting an approach compatible with sustainable development principles, including adhering to the Federal Code of Environmental Stewardship (Table 1.1), to the latest federal policy on Greening of Government Operations,[5] and to other related policies.[6]
Within Public Works and Government Services Canada (PWGSC), Real Property Services (RPS) have the most input in the development of the departmental SDS. The branch has committed to sound environmental practices (management); and to achieve this goal, environmental goals and objectives have been formulated. They are summarized in Table 1.2, together with the potential impact on building design. They address the dual role of RPS as a "provider of services" to clients, and as a "custodian" of Crown-owned and leased inventory of buildings and other property assets.
Table 1.1: Code of Environmental Stewardship
The Federal Government is committed to:
- Detailing so that long life components will not be damaged when shorter life span elements are being replaced;
- Meeting or exceeding the letter and spirit of federal environmental laws and, where appropriate, being compatible with provincial and international standards;
- Improving the level of awareness throughout the public service of the environmental and health benefits and risks of operational decisions and to encourage and recognized employee actions;
- Applying environmentally responsible management strategies to hazardous substances used in operations, specifically with regard to the acquisition, handling, storage, safety in use, transportation and disposal;
- Seeking cost-effective ways of reducing the input of raw materials, toxic substances, energy, water and other resources, and of reducing the generation of waste and noise associated with day-to-day activities;
- Ensuring that environmental considerations are integrated into government purchasing policies and practices;
- Acquiring, managing and disposing of lands in a manner that is environmentally sound including the protection of ecologically significant areas.
1.2 Greening of Government
Addressing the environmental agenda will require an explicit restructuring of priorities and a questioning of a host of related assumptions which directly and indirectly shape buildings.
In April 1995, the Federal government approved a coordinated approach to green government operations. The policy on Greening of Government Operations commits federal organizations to address a number of specific issues in their sustainable development strategies.
Table 1.2: RPS Environmental Goals and Objectives
1: Toxic or Hazardous Substances and Waste Management
Real Property Services (RPS) will contribute to the prevention, reduction and, where possible, the elimination of impacts of toxic or hazardous substances and wastes on human health and safety.
Design consequences:
- Handling of Polychlorinated Biphenyis (PCBs) when replacing electric lighting installations;
- Specification of environmentally sound building materials;
- Specification of low maintenance systems and finished;
- Site landscaping to treat storm water.
2: Ozone Depleting Substances Management
RPS will phase out the use of ODSs to respond to the deadlines laid out in the 1987 "Montreal Protocol on Ozone Depleting Substances" and its subsequent amendments.
Design consequences:
- Education or elimination of ozone depleting substances.
3: Non-Hazardous Solid Waste Reduction
RPS will:
- Contribute to the objective of reducing the amount of office solid waste sent for disposal by at least 50% by the year 2000 relative to 1988 levels;
- Facilitate the reduction of construction, renovation and demolition waste.
Design consequences:
- Provision of adequate facilities to promote waste recycling programs;
- Specification of renewable, recycled content, durable and maintainable materials;
- Conscious design and construction planning to minimize construction and demolition waste.
4: Energy and Water Efficiency in Facilities
RPS will:
- Contribute to the use and promotion of more efficient, environmentally friendly alternative sources of energy to heat, cool, ventilate and provide lighting and power facilities. It will also promote the efficient use of water.
- Reduce gas emissions to respond to Canada's commitment to the requirements of the 1992 'Framework Convention on Climate Change'.
Design consequences:
- Improved building energy efficiency;
- Higher energy performance standards, use of clean; renewable energy sources;
- Specification of low embodied energy building materials;
- Use of low water consumption appliance and water efficient landscaping strategies.
5: Contaminated Sites Management
RPS will contribute to the prevention, reduction and, where possible, the elimination of negative impacts of contaminated sites on humans and the environment.
6: Land and Marine/Fresh Water Activities Management
RPS will contribute to the prevention, reduction and, where possible, the elimination of negative impacts on humans and the environment in their land and marine/fresh water activities.
Design consequences:
- Greater understanding about implications of building construction and operation of site;
- Landscaping strategies which enhance site ecology;
- Construction practices which reduce environmental impact and construction waste.
Departments and agencies must:
- Meet or exceed federal environmental statutes and regulations;
- Emulate best practices from the public and private sectors;
- Develop and implement environmental management systems, including action plans.
They must give priority to a pollution prevention approach in the greening of government operations; this is achieved by using processes, practices, materials, products or energy that avoid or minimize the creation of pollutants and waste, and reduce overall risk to human health and the environment. The Greening of Government Operations form an integral part of sustainable development strategies.
The key federal statutes which focus on environmental quality include the:
- Canadian Environmental Protection Act (CEPA)
- Canadian Environmental Assessment Act (CEAA)
- Canada Wildlife Act
- Fisheries Act
- Transportation of Dangerous Goods Act.
In particular, the CEAA is likely to impact the design on new and renovated buildings. Under this Act, a project must be screened for its environmental impacts at the earliest possible stage before any irrecoverable decisions are made. Also, the design must incorporate any mitigative measures that have been identified in any environmental assessment studies conducted to meet CEAA requirements. In addition, a monitoring program for the anticipated environmental impacts and for the effectiveness of the corresponding mitigation measures must be included in the design.
1.3 Design Priorities
Legislation and public policy, the free market and infrastructure, natural events, and personal design philosophies all affect progress toward sustainable objectives.
Implicit in all Real Property Services goals and objectives toward environmental responsibility are the commitments to address the specific issues laid out in the policy on Greening of Government Operations:
- To keep pace with all significant environmental legislation, developments and initiatives;
- To offer services to RPS clients for the management of environmental issues;
- To pursue environmental research, development and demonstration;
- To develop and implement educational programs and aids to train employees involved with environmental activities and services;
- To participate in the development of environmental legislation and communicate RPS environmental expertise.
Table 1.3: Design Responsibilities
The environmental agenda will require architects and other design professionals to:
- Understand the emerging environmental agenda and develop the appropriate knowledge and skills to be able to respond accordingly on all design projects;
- Challenge existing design norms and reassess each design project on its own merits;
- Be open and receptive to emerging environmental ideas and be willing to re-evaluate best practices;
- Establish a coordinated team approach to design in which every member of the design team is, at some level, aware of and can make timely contributions to all the significant design issues;
- Look creatively at reusing existing buildings, materials and components in conjunction with a host of new materials that will become available as the building industry examines innovative ways of turning wastes into resources;
- Develop new skills, knowledge, and attitudes to support renovation work and to learn to be more curators of the built environment rather than creators;
- Examine the cost effectiveness of environmental strategies within a comprehensive analysis of total renovation costs and not simply evaluate them on the basis of the incremental cost-benefit of the strategy alone.
These collectively mean that design teams working on federal projects will be dealing with clients who:
- Are more aware of environmental issues;
- Are more committed to the implementation of improved environmental strategies within their facilities;
- Expect environmental issues to be explicit in all phases of the design process.
This will affect the knowledge and responsibilities of design professionals and the relationship between them (Table 1.3).
The conscious choices architects and other members of the design team face in deciding how to design buildings will have a profound influence on the future health of the planet. Environmentally responsive design involves satisfying human activity using resources efficiently and effectively, and with minimum stress on natural systems. It will affect and dictate whether we build, where we build, what we build and how we build.
We are currently in the early stages of a transition toward sustainability. It will take a considerable amount of time before a comprehensive environmental design ethic creates a realignment of priorities. It is the transition from the current period to such a future time that we can anticipate inevitable contradictions and difficulties. All aspects of 'sustainable' building design and operation will continue to be clarified and redefined.
Sustainability requires first and foremost an attitudinal shift, to embrace new ways of thinking about the processes of production, use and disposal of building. It is incumbent on all those responsible for building design and operation to begin to chart this new direction.
These guidelines emphasize environmentally responsible building design practices which establish the environmental agenda as fundamental design criteria and which result in innovative and progressive methods of construction and operation. Adherence to current economic imperatives must be maintained, but considerable advances are expected to be made in terms of resource efficiency and minimizing environmental impacts. Wherever possible and appropriate, design should challenge existing design norms and adopt innovative, more environmentally appropriate strategies which reduce environmental impacts and operating costs throughout the lifetime of buildings.
Such a realignment will require:
- The continual questioning and re-examination of traditionally held attitudes and approaches to design;
- Transcending professional boundaries between architects, engineer and all others involved in the production of buildings.
| Health and Well-being | Ecological | |
|---|---|---|
| Resource Use | Ecological Impacts | |
| Thermal Quality | Land Use | Global Warming |
| Indoor Air Quality | Energy Use | Air Pollution |
| Lighting Quality | Material Use | Waste |
| Acoustic Quality | Water Use | |
1.4 Environmental Issues
Environmental issues relevant to buildings include both occupant health and well-being and ecological impacts. (See Table 1.4)
Health and well-being design issues include the provision and maintenance of thermal, indoor air quality, lighting and acoustic conditions which directly and indirectly affect building occupants.
The ecological design considerations comprises resource use issues and environmental impacts:
- Resource use concerns centre on the depletion of land, energy materials and waters resources and how improved building design can employ them more efficiently and effectively;
- Ecological impacts cover the broad range of adverse impacts caused by the construction, operation and demolition of buildings.
1.5 Renovation of Buildings
Improved energy standards and increased potential for recyclability and reusability in buildings constructed from this point in time alone will not be sufficient to realign the built environment towards a sustainable future. Attention must be directed at the use and upgrading of the existing building stock.
Although the rehabilitation and reuse of buildings was originally a product of the historical preservation movement, today this growing trend also reflects a changing attitude towards resource use and a realisation of the economic and environmental limits to growth. Indeed, the beginning of the next millennium will mark a "shift from the era of building to the era of rebuilding".[7]
Demographic and economic factors, such as an oversupply of commercial buildings, slow economic growth and a decrease in the rate of population growth, have contributed to a decrease in demand for new construction:
- Both the public and private sectors will increasingly be forced to respond to needs for office space by renovating rather than building new;
- Improved energy and environmental standards for new buildings alone will not meet national environmental targets.
PWGSC office facilities consists of some 370 Crown-owned office buildings, amounting to approximately 3 million m2 and valued at about $2.2 billion. About 85% of these buildings are more than 25 years old. In addition to the aging asset base, significant changes are currently taking place in the federal government that have an impact the demand for new construction: new technologies and trends towards flexible work arrangements are redefining the workplace.
Also, reorganization and consolidation of federal government operations implies substantial rationalization of the Crown portfolio over a 10-15 year period. Integral to RPS strategic directions is the commitment to bring Crown-owned facilities up to full environmental standards as quickly as possible, subject to resource availability.
1.5.1 Extent of Renovation
Renovation can range from relatively straightforward reorganization of interior space through to the complete upgrading of the building envelope and building systems.
Four levels of renovation can be considered:
- Major renovations that generate significant waste because parts of the structure are removed and/or replaced;
- Minor renovation as part of routine repair and maintenance on the building;
- Fit-up projects, where the facility is adjusted from base building standards to fit the needs of the tenants;
- Tenant service renovations which the tenants conduct themselves.
Each renovation project presents its own unique problems and opportunities to provide cost-effective environmental upgrading.
A prerequisite to consider in renovation projects is a detailed audit of the existing environmental characteristics of the building including energy, water and materials. This is not considered in this guide but appropriate procedures are identified in the Building Renewal Evaluation Guide.[8]
1.5.2 Environmental Benefits
Although most of the buildings in a city are not landmarks and may possess only marginal cultural and historical significance, they are valued for other reasons, such as the distinctive character and quality that they give to established urban areas.
Despite their lack of landmark status, the more modest buildings that constitute most of the urban fabric of Canadian cities represent a huge investment of capital and resources. Demolition of these buildings is a "flagrant waste of materials and energy", and their conservation becomes more an environmental issue than a cultural one.[9] Table 1.5 presents the environmental advantages of re-using office buildings.
1.5.3 Economic Benefits
Generalized statements about the cost of renovation versus new construction are difficult to make because of the large number of variables involved. Every project is unique and costs will vary depending on the extent of the work that is required. A large commercial rehabilitation can cost anywhere from 12% less to 9% more than comparable new construction that takes place on an empty site.[10]
Table 1.5: Environmental Benefits of Renovation
1: Conservation of Resources
As supplies of non-renewable resources are depleted, and as the costs of remaining sources increase, the conservation of all resources will become far more important.
- Although reusing buildings undoubtedly conserves resources, buildings are largely composed of materials that are relatively plentiful: gravel, stone, and cement with steel and lumber typically being the next two highest ranking materials;
- The environmental costs producing these materials is currently a more important concern than their conservation.
2: Reduced Environmental Impact
An existing building represents a concentration of natural and manufactured materials, the environmental impacts of which were incurred many years ago.
- Retaining buildings and upgrading or adapting them for new uses reduces the currently environmental damage caused producing materials such as steel and concrete. Reusing buildings requires lower quantities of these materials since a structure is already in place.
3: Energy Invested in Existing Buildings
Reusing old buildings conserves embodied energy.
- Existing buildings represent a past investment of large amounts of energy invested in the processing, manufacturing, transportation, and assembly of their constituent materials. This investment is known as a building's "embodied energy".
4: Energy Efficiency
Many older buildings from the late 19th and early 20th Century can use less energy than newer buildings.
- The thermal mass provided by thick masonry walls tempers heat gains much more effectively than the glass and steel curtain walls of later structures;
- Pre-World Ware II buildings usually relied on natural light and ventilation and their relatively smaller window areas and external shading devices reduced solar heat gains.
5: Reduced Volume of Waste in Landfills
Debris from demolished buildings, if not recycled, is dumped into local landfills.
- With many landfills reaching their capacity, reducing the volume of waste is becoming a critical environmental concern;
- Reusing buildings also saves the energy that would be required to demolish them.
6: Reducing Suburban Sprawl
Reusing and adapting existing or under-utilized buildings can help rejuvenate old neighbourhoods and slow the rate of urban sprawl which destroys agricultural land and increases energy required for commuters.
7: Changed Attitudes
Indirectly, reusing existing buildings encourages the idea of designing for longer life-cycles and taking into account the long term economic and environmental consequences. Reusing old buildings is part of a move away from the "throw-away" mentality of the past.
8: Cultural Heritage
There is a need for cities to preserve their physical memory. Buildings provide a physical link to the past.
- The preservation of buildings helps to maintain a unique sense of an increasingly standardized world;
- Cities are enriched by the character and scale that older buildings add to the built environment.
9: Abundant Supply
In some parts of the county with a long urban history there is a large supply of older buildings that can be utilized for new purposes.
10: Existing Buildings as a Resource Base
The existing building stock represents a vast source of future building material. Although it was created without a view for reuse or recycling of materials, a large portion of it will be re-made into 'new' building.
In a situation where an existing structure must be demolished before new construction can begin, renovating the building instead can cost anywhere from 3 to 16% less. If major elements such as mechanical, electrical, or plumbing systems, windows, roof, etc., can be reused, cost savings will be greater. Construction costs for minor renovations usually range from 40 to 50% of those of a comparable new structure.[11]
Table 1.6 presents the economic advantages of reusing office buildings.
Table 1.6: Economic Benefits of Renovation
1: Demolition Costs
Reusing old buildings saves demolition costs:
- Demolition can account for as much as 5 to 10% of total construction costs;
- In urban areas, where safety concerns can restrict the methods of demolition that can be used, building demolition and removal can be very expensive and time consuming.
2: Land Costs
Reusing an existing building save the high cost of purchasing undeveloped land.
With rising land costs, even in outlying areas, there is less reason to build on vacant land in outlying areas rather than renovating an existing structure in an already built-up area.
3: Construction Time
The total amount of construction time required to renovate an old building is generally less than the time required to build a comparable new facility.
- Renovation work can take place year round since contractors can work inside during the winter months and there is no need to wait until spring to do excavation work;
- Less construction time also leads to reduced interest costs and an earlier rent income.
4: Staged Construction
Buildings can be renovated in stages so that one section can be completed and occupied before work begins in another area.
- This provides a source of income for developers during the construction process;
- With higher interest rates, and longer delays in the availability and shipment of required building materials prolonging construction time, the lag between construction and occupancy will become an increasingly important cost factor.
5: Desirable Accommodation
Renovated buildings can be as, if not more, desirable than newer ones and command high rent.
- The unique character of old buildings, a product of their age and craftsmanship, offers a quality rarely obtained in new construction;
- Features such as high ceilings, large windows, ornamental woodwork, often found in old buildings, can greatly improve the marketability of rentable space.
1.6 References
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WCED, (1987) Our Common Future. [The Brundtland Report]. Oxford, Oxford University Press (for) UN World Commission on Environment and Development, p. 393. (back to 1)
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Creating Opportunity, The Liberal Plan for Canada, Liberal Party of Canada, Ottawa, 1993. (back to 2)
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Slow, R., 1993, An Almost Practical Step to Sustainability, reviewed in Resources, 110, Resources for the Future, 116 P Street NW, Washington DC, 20036-1400. (back to 3)
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Hill. R.C., et al, 1994, P.A., A Framework for the Attainment of Sustainable Construction, Proceedings CIB TG-16, Sustainable Construction Conference, Tampa, Florida, 1994, pp. 13-25. (back to 4)
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A Guide to Green Government, 1995, Ministry of Supply and Services, Ottawa, Cat. No., En 21-136/1995E. (back to 5)
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Directions in Greening of Government Operations, 1995, Public Works and Government Services Canada, Ottawa, Cat No. 40-497/1-1995E. (back to 6)
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Levinson, Nancy, "Renovation Scoreboard". Architectural Record. Vol. 181. January 1993, p. 70. (back to 7)
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Building Renewal Evaluation Guide, Real Property Services, Public Works and Government Services Canada, Ottawa, 1996. (back to 8)
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Kalman, H., The Conservation of Industrial Buildings: Feasibility and Practice. The Heritage Canada Symposium, 1976, p. 4. (back to 9)
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Rypkeme, Donovan D., "Making Renovation Feasible." Architectural Record. Vol. 80. No. 1. January 1992, p. 27. (back to 10)
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Rypkeme, Donovan D., 1992. (back to 11)