Fire Protection Engineering Bulletin
Date : February 3, 2016
Subject: Rehabilitation of Existing Buildings – Listed Historic and Other Structures.
Issue Number: 2016-01
While new condominiums represent the largest segment of property entering the market, refurbished buildings are in high demand due to their aesthetic appeal. The lack of availability makes these properties attractive to developers as potential rentals and condominium conversions.
The property market dictates the price of accommodation; however, there are many factors affecting the cost of renovations and the ease to which buildings can be modified and upgraded to a reasonable standard. If these costs can be reduced then it increases the bottom line for developers. This cost reduction increases the potential supply of units in the market place. This helps bring supply and demand back into balance.
In the City of Vancouver the aim is to align the scheme for upgrading buildings with Part 11 of the Vancouver Building Bylaw. This Part is now relatively comprehensive and has improved significantly since the 1980’s. Although this bulletin focusses on the Vancouver Building Bylaw it should help inform the approach to be used in other centres. In general, two strategies may be used to define the scope of an upgrading project in cases where the building and/or proposed changes do not qualify for an exception to the upgrading requirements:
Option 1: Identify the scope of upgrading using Vancouver Building Bylaw Part 11 and Division B Appendix A-184.108.40.206. This requires you to select the appropriate chart for the categories of work and extent of upgrading. Many practioners use these requirements and it does not take a significant level of technical expertise to apply the rules.
Option 2. Carry out a fire risk analysis and building code assessment to develop a bespoke strategy for the building improvements. This includes obtaining concurrence of the City / authority on the proposed programme and the intent of the Part 11 / Appendix A requirements for the specific project.
USING OPTION 1
While Option1 may seem the most practical there are several reasons why this is often not the optimum approach:
- The one constant is the endless variety of heritage projects, specific non-conforming features and issues that have to be addressed. If these issues are not dealt with, they will emerge as unanticipated problems and costs in the construction/inspection phases. This is expensive; consequently, all details have to be tied down.
- The current bylaw represents the ‘best practice’ based on experience on heritage buildings to date but it has to be constantly updated to reflect new conditions as they are encountered on different projects. The incremental changes are usually made at each code cycle.
- Conservation should be the driving force of any heritage project. Often the fabric of the building necessitates a different approach to issues such as fire resistance and combustibility of construction. Key features- for instance, exposed heavy timber or large dimension joists- should be retained wherever possible as they reflect the original character of the period.
If the City staff are asked for advice independently they may take the ‘worst case’ approach and this can significantly increase the project scope and costs.
- Ultimately there has to be a process with which the project is aligned. These fall into planning or building permit realms. While building permit processes may be relatively well-defined, in practice numerous issues can delay or complicate a project. Planning is more subjective and the process may become as much political as it is technical.
Figure 2: Larger dimension joists are typical of low-rise Yaletown and Gastown Buildings. These were retained based on improved sprinkler performance requirements.
Planning in Perspective
When a heritage building forms part of a larger development site- combined with new structures- the heritage building may be treated differently to a single heritage building on a site. In the past, the authority has been sufficiently flexible to permit the heritage component of a larger project to be upgraded to a ‘reasonable’ standard rather than to be fully upgraded to Code. Any legal agreements that dictate that upgrading levels must be to current codes should be interpreted reasonably i.e. in the appropriate context for the heritage building. There is no point in requiring full upgrading of any heritage building to current codes. It is counter-intuitive and inconsistent with heritage conservation principles. It is also significantly more expensive and perpetuates the myth that renovation of a building costs more than new construction.
Similarly the conversion of an existing building to condominium use should have reasonable caveats applied. The price for meeting full code requirements can be virtual reconstruction of a building. Any requirement that is imposed to this effect is counterproductive; numerous studies have shown that upgrading an existing building- rather than demolishing it and building new- is both less costly and has a lower carbon footprint than new construction. Therefore any scheme which requires removal of floors and other essential building fabric cannot be easily affordable or considered sustainable.
Many developers rely on architects to come up with a scheme to adapt a building for a new use. While this is an effective strategy, certain architects excel at renovation; others may be less sensitive to retention of the features of a building. Developers that focus on renovation as a principal part of their portfolio have to assemble the best tools at hand to make the project successful. Certain principles have emerged on how to do this.
- The heritage features and circulation should be retained or re-used if possible in the new design. Fabric that is proposed to be removed should only be removed if absolutely necessary based on the benefits and costs.
- Most heritage buildings have existing stairs and any scheme to create new stairs can be invasive. Early reinforced concrete construction does not lend itself to the penetration of floors to create new scissor stairs for instance. The more invasive a scheme is, the bigger the impact on structural upgrading required. Using existing stairs is a more effective way to approach the exiting scheme.Exposed wood floor and roof structures are often a key feature of heritage buildings in Gastown, Yaletown, Victoria and other historic centres.
- The material is often clear fir or other old growth timber. Strategies can usually be developed that enable such structure to be cleaned and restored to their original patina/visual condition. Upgrading by encapsulation using gypsum board is counter-productive, invasive and is not recommended for sustainability and other reasons
Figure 3: The preservation of buildings in Gastown has created a successful neighbourhood / tourist destination
Note: For large facilities such as heritage town sites, conservation is the prime driver and often the strategy is site-wide to enable infrastructure to be established and upgrading facilitated across many buildings rather than to deal with them individually.
Heritage Buildings and Planning processes
A strategy to upgrade a heritage building should be sensitive to the building. While transfer of density is an option under Heritage Revitalisation Agreements (HRA’s), any arrangement concerning upgrading an existing building fully should not arbitrarily impose onerous upgrade requirements without the fire protection engineer assessing whether the schedule of work is reasonable under the Part 11 guidance.
The strategy should be respectful of the building and relatively easy to implement without invasive processes including un-necessary demolition.
Many heritage buildings can be upgraded with little or no impact on the exterior of the building. This begs the question why such buildings could not be fast-tracked through the planning approval processes? Even simple projects are being routinely delayed for extended periods. Obviously occupancy changes, additions have to be assessed for their impact on the community.
On the whole, the heritage planners are sensitive to the practicalities and will process their reviews in a reasonable time. Planning applications should be fast-tracked where existing construction is involved. By rolling renovations into the mainstream planning process, routine building projects are being held up by complex new- builds which require extended planning processes to obtain public approval. This un-necessarily delays projects in major centres involving conversion to residential and other occupancies. Such refurbishment projects typically have a positive impact on the areas in which they are located; even major conversions and additions- within reasonable bounds- should be encouraged and fast-tracked rather than be excessively scrutinised. If a building already exists it should be implied that it is already appropriate in its location and thereby easily adapted to suit new needs.
In particular consideration should be given to a new process exclusively for existing buildings to facilitate adapted re-use and fast-tracked changed to bring housing supply back into balance.
USING OPTION 2 – THE RISK-BASED APPROACH
This approach enables the proponent to:
- Maximise the use of existing heritage features and building features rather than to drive excessive internal changes with greater impact.
- Develop a fire strategy around the essential heritage features and compensate for inadequate fire resistance of fire separations and other features by compensating in other ways.
There are several important steps to be followed to achieve this:
- A complete fire risk assessment and identification of all potential building code issues should be undertaken before the architectural scheme becomes well established and irreversible. It is not uncommon for architects and developers to make assumptions about the level of upgrading and this combined with a more aggressive scheme of conversion can, in combination with other factors, render the scheme so costly to implement that only key features such as the external walls can be saved. This should be regarded as failure of the whole process.
- The impact of the changes that are planned have to be assessed and a rational concept for upgrading the building developed for alignment with Part 11. Based on previous projects the following factors can be considered in bringing the upgrading concept together.
- If the fire risk of the building is fully addressed then all the other issues are put in perspective and can be carried forward to the City as part of the process. This builds trust with the authority and also help to put the strategy into better perspective
- Assess how the Owner’s aspirations fit into this process. If there is extensive cosmetic work such as renovations of a hotel then those items should be separated from associated upgrade work that will be undertaken. The work usually presents the opportunity to undertake other upgrading work such as those to fire and life safety systems.
- The mechanism for the level of upgrading should be clear. However, there may be a compelling argument to take a different approach. This inevitably arises because the features are different than those anticipated. It is a good general principle that the building will tell you what it wants to do and the rest should be how to retain these building features as a fundamental part of an upgrading scheme. If your process works the other way around then you will not be undertaking the project in the best way for the building and you will find yourself dictating to the building fabric rather than the other way around.
Involving a fire protection engineer early in the process is essential as the strategy for upgrading can be discussed before the level of upgrading becomes locked in stone.
The fire protection engineer/code consultant should be able to deliver a broad-based agreement with the authority. This should include the level of seismic upgrading and other upgrading work such building envelope and accessibility.
Figure 4: External brace on Railway Street: a unique solution to lateral restraint – John Bryson and Partners
Without a close working relationship with the structural engineer, the Owner and the fire protection engineer/code consultant, it may be assumed that full seismic upgrading is required. By driving this process the fire protection engineer can determine the actual level of seismic upgrading required achieving significant cost savings in the process.
Some structural engineers are more comfortable working with renovations and have shown flexibility and creativity in their work as well as willingness to align their design to the agreed upgrade scheme. If any engineer or architect tells you that full upgrading is inevitable this is a red flag.
Once the fire protection engineer/code consultant has fine-tuned the fire strategy then the structural engineer should support his or her role and represent the joint position of the team in a meeting with the City.
Figure 5: This feature stair was recently removed as new stairs were created as part of the architectural design.
THE BUILDING PERMIT PROCESS
If the scheme involves architectural changes of significance then there will be an architect retained to carry out a design. Some architects have evolved their service over the years into a full service for renovations. Such professionals are also cognisant of the conservation issues. This is true in both Canada and the UK.
Where there is a major addition to a building such as a horizontal addition to a school or hospital there may need to be a programme for upgrading the building as a whole. This then poses the problem: who should coordinate the project to implement the upgrading requirements? Where the code consultant does not undertake design work, the project typically requires mechanical, electrical and other consultants to complete the design. If a structural engineer or geotechnical engineer is required this makes the task of coordinating the design challenging.
Depending upon the scheme it may be possible to streamline the number of consultants required to complete a project.
Certain fire protection engineering firms undertake design of projects and this enables them to reduce the number of consultants required to implement the design. Much design work in the City of Vancouver until 2001 was carried out on this basis. The same strategy has been used on major heritage upgrading projects undertaken by the Province of BC.
In all cases, it is essential that the agreement on the extent of upgrading be reached before the design development takes place. If not, then it is typically too late to control the extent of work of the consultants and costs get out of control.
CERTIFIED PROFESSIONAL PROGRAMME
The predominance of Certified Professionals has enabled them to coordinate the Code conformance of projects. The lack of a streamlined process for carrying out the design of renovations has driven up the number of consultants and the schemes towards full code compliance with relatively few exceptions. This is because the underlying model for conformance is the building code for new buildings which is never an effective fit for heritage and other existing buildings. Unwittingly the CP process, though effective on new buildings, may have complicated and increased the cost of renovation. This along with other factors has reduced retention of features of existing buildings and increased demolition and costs.
Figure 6: This infill Building in Gastown formed part of a block-wide seismic strategy
If a strategy is worked out by a fire protection engineer/code consultant that is bespoke then it makes sense that the coordination should be managed by the same party and if possible key elements of the design such as the fire protection systems and related work undertaken by the same party.
If the fire protection engineer/code consultant works with the City then certain aspects such as reasonable changes to existing stairs can be worked through with the City building inspector to achieve practical improvements rather than application of literal requirements of the code necessitating replacement of stairs.
- A risk-based approach by which heritage and other existing buildings are fully assessed is typically more flexible and enables retention and heritage conservation to form an integral part of the strategy. Retention of individual building features should drive the upgrading scheme.
- An overly adventurous or invasive design scheme for the building will exacerbate the fire and building code problems, escalate construction costs and complicate and delay planning approvals.
- A streamlined approach to planning is required where there are nominal exterior changes and uses are consistent with the area plan. This would help facilitate residential conversion and make rental and other housing more affordable.
- Fire and building consultants should be responsible for reaching consensus with the authority; they should lead on issues such as the reuse of existing stairs and exposed heavy timber. Strategies should be adapted to retain key heritage features.
- Some details are best left to the District Building inspector to work out on site. Such issues should be identified at the agreement stage. This can avoid the need for costly Alternative Solutions.
- A new process for renovations should recognise the bespoke nature of upgrading and use a customised checklist based on the agreement with the authority rather than a complex checklist based on new building projects.
- A reduction in soft costs can be achieved if the fire and building code consultant can carry out much of the design work rather than reliance on a conventional team less familiar with fire and life safety systems.
- Structural consultants should rely on the upgrading strategy reached with the City as significant reductions in costs can be achieved if aligned with the nature and extent of changes. The fire protection engineer/building code consultant should take the lead on this.
Prepared By: John T. Ivison
January 15, 2016