Reading an article on acoustics in the July 2012 issue of The Construction Specifier reminded me of a number of useful lessons learned in the process of designing and administering public school construction projects. Here is one:
Basic Acoustical Treatment for a School Gymnasium: Although acoustical treatment on walls and ceilings is commonly omitted or is eliminated through value engineering, it is typically crucial for a gymnasium. Some basic guidelines provided by an acoustical consultant on a school project 20+ years ago have proven helpful on several other projects. The guidelines related to a gym with a single basketball competition court, a substantial bleacher area, and a clear height of approximately 25 feet to the underside of the roof structure. The guidelines were simple: Cover approximately 15% of the wall area and 50% of the overhead (roof/ceiling) area with a well distributed array of acoustical panels. The panels were the equivalent of 1.5-inch thick wood fiber (Tectum) mounted on furring and backed by a layer of batt insulation. The distribution of the panels is important in order to adequately reduce sound reflection in the large space. We utilized a checkerboard pattern of panels on the upper half of all walls, and we covered every second joist bay of the underside of metal roof deck.
In practice, the 15+50 surface applied acoustical treatments described above have generally been more successful than "built-in" alternatives like acoustical concrete masonry units (e.g., "SoundBlox") and acoustical metal decks (including (1) those with perforated flute walls and laid-in fiberglass strips and (2) cellular acoustic deck with a perforated bottom plate and internal insulation).
The 15+50 surface applied acoustical treatments described above have also proven to be acceptable "fixes" for existing or newly constructed gyms of similar size that suffered echo chamber effects and were considered too noisy for normal use.
(It should be noted that the basic guidelines described above will not be effective in every situation, and larger or different spaces are likely to need different percentages and/or different types of acoustical treatment. In addition to acoustical consultant resources, there are good published resources available to architects; one such publication is Architectural Acoustics - Principles and Practice (available as an NCARB monograph).)
School Construction Photo
A job site photo of a school under construction
Tuesday, July 3, 2012
Saturday, May 12, 2012
Rethinking the Cost of Time
Building design and construction have been governed in modern history by our modern perception of time as a cost based commodity. Both design and construction are assumed to have greater competitive value if production time is minimized. The first cost is generally lower if it takes less time to design and build a project. We can generally recognize a disconnect between first cost and long term cost when we consider building products (e.g., cheap windows vs. expensive windows), where lowest first cost may lead to higher long term costs in energy usage, maintenance, and replacement. Yet, as a profession and an industry, we have not been able or willing to pursue the long term value of time invested in design and construction, such that more available time (if well managed) results in more integrated attention to systems and details that enhance long term building performance and optimize long term operating costs. This issue is most notable in our continuing willingness to commit to abbreviated time periods for design and construction. We talk about the value of high performance buildings in terms of energy efficiency and healthful environments, yet the market continues to demand speed over performance due largely to the long established premise that "time is money" - a premise that is reinforced by the owner who wants the building quicker and by the designer and contractor who must bid low to get the job and then minimize time in order to avoid loss. When minimizing time is the highest priority, long term performance does not enjoy equal consideration. Owners, designers, and contractors need to rethink the cost (and focus) of design and construction time as they relate to long term building performance. We have come to recognize long term risks associated with fast food; fast construction deserves similar consideration.
Thursday, March 29, 2012
Who Should Answer This Question?
Architects are faced with questions all the time. Clients ask questions. Consultants ask questions. Contractors and subcontractors ask questions. The list goes on. Architects generally want to be helpful, they like to be asked questions, and they want to have the answers - ideally, all the answers - at the ready. But, they don't always have the answers. Instead, they may know more about where to get the answer and who is the most appropriate person or entity to provide the answer. If they don't know on first thought, they may be able to figure out who should answer the question. Although the persons who ask the questions usually want a direct answer and may even be suspicious of a suggestion that another party may have the answer, that suggestion may in fact be the best answer the architect can offer.
Architects visiting a construction site are likely to be asked questions by subcontractors that should be answered by the General Contractor (G.C.). For example, the architect may want to answer a question about sequence, but there is a risk that the architect's best answer will contradict the General Contractor's plan of attack for the project. Knowing that the G.C. is responsible for deciding sequence, the architect should refer the subcontractor to the G.C. Even if the subcontractor's question appears to be about the content of plans or specifications, the architect should only answer it in the presence of the G.C. and should address the answer to the G.C. This may seem overly formal or "stiff", but the architect must respect the G.C.'s authority on the job site. This approach allows the G.C. to answer the subcontractor's question.
Another kind of question that an architect might be asked is one that should actually be answered by an owner. The question might relate to use of a particular space, and the architect's information about the use of the space may not be complete enough to answer the question. In that case, the owner must be consulted for the answer.
It's healthy for the architect to recognize questions, whether they are actually asked or simply appear as decisions or choices to be made in the design process, and to consider who should answer the questions or make the decisions or choices. In some instances, the questions will be best answered after consultation with more than one party.
We hear architects talk about "getting into trouble", and it is often the answers they offer or recommendations they make that get them into trouble. One way to minimize the "trouble" is to consider who should answer a question before offering an answer.
Architects visiting a construction site are likely to be asked questions by subcontractors that should be answered by the General Contractor (G.C.). For example, the architect may want to answer a question about sequence, but there is a risk that the architect's best answer will contradict the General Contractor's plan of attack for the project. Knowing that the G.C. is responsible for deciding sequence, the architect should refer the subcontractor to the G.C. Even if the subcontractor's question appears to be about the content of plans or specifications, the architect should only answer it in the presence of the G.C. and should address the answer to the G.C. This may seem overly formal or "stiff", but the architect must respect the G.C.'s authority on the job site. This approach allows the G.C. to answer the subcontractor's question.
Another kind of question that an architect might be asked is one that should actually be answered by an owner. The question might relate to use of a particular space, and the architect's information about the use of the space may not be complete enough to answer the question. In that case, the owner must be consulted for the answer.
It's healthy for the architect to recognize questions, whether they are actually asked or simply appear as decisions or choices to be made in the design process, and to consider who should answer the questions or make the decisions or choices. In some instances, the questions will be best answered after consultation with more than one party.
We hear architects talk about "getting into trouble", and it is often the answers they offer or recommendations they make that get them into trouble. One way to minimize the "trouble" is to consider who should answer a question before offering an answer.
Monday, March 19, 2012
Interdisciplinary Coordination of Construction Documents
Gaps between design disciplines are a common cause of construction change orders. In some cases, the consulting disciplines' standard practices may generate a gap. For example, the electrical engineer may establish an electrical scope of work that "stops" 10 feet outside the building, while the site civil engineer may expect (and indicate on the site drawings) that the electrical contractor will provide power to a sewage lift station that is 15 feet outside the building. Unfortunately, it is quite possible that neither the electrical engineer nor the civil engineer will become aware of this gap in electrical service until the contractor submits an RFI.
Similar gaps can occur between plumbing and site trades, between mechanical and general building trades, between structural steel and miscellaneous metals trades, and between other trades. In most cases, proactive coordination by the project architect during the construction documents phase can help to minimize these gaps."Proactive" coordination means getting involved in finding and highlighting possible gaps and managing document revisions to eliminate the gaps by conferring with the related disciplines, considering applicable trade practices and regulations, and assigning responsibility to the most appropriate party. (It's usually not enough (and not really proactive) to simply tell the consultants to work it out between themselves.)
Similar gaps can occur between plumbing and site trades, between mechanical and general building trades, between structural steel and miscellaneous metals trades, and between other trades. In most cases, proactive coordination by the project architect during the construction documents phase can help to minimize these gaps."Proactive" coordination means getting involved in finding and highlighting possible gaps and managing document revisions to eliminate the gaps by conferring with the related disciplines, considering applicable trade practices and regulations, and assigning responsibility to the most appropriate party. (It's usually not enough (and not really proactive) to simply tell the consultants to work it out between themselves.)
Friday, March 9, 2012
Code Talk: Challenges for Architects
Most of the architects I have known are not comfortable with codes. They want to comply with applicable codes, but they find them confusing, tedious, contradictory, or even frightening. Codes are always being revised or superseded. It takes time to determine how a combination of applicable codes can be reasonably applied to a particular building type and scale, and it seems that the codes are changed almost as soon as the architect reaches a level of comfort with the requirements.
One of the reasons that it takes more than a little time to determine the application of codes to a specific project is that codes tend to be dense and voluminous texts that are full of "fine print", numerous exceptions and cross references, and hierarchies that are hard to follow (i.e., "Which article has precedence in this situation?"). Further, the architect is usually charged by statute with the professional responsibility to account for the application of numerous, differing codes - on the same project. In some cases, state or local authorities have adopted parts of different codes that cover similar matters, adding their own hierarchies to interpretation of requirements, and the architects are challenged with having to determine how to resolve gaps and conflicts that have not been addressed by the state or local authorities. Codes that include graphic illustrations of requirements are generally easier for architects to understand, because many - if not most - architects tend to think graphically. In that regard, accessibility guidelines that rely on graphic illustrations have been much easier to follow than text-only codes. Code commentaries or handbooks such as those available from ICC and NFPA can be more useful than the codes themselves due to the use of graphic illustrations. Graphic illustrations can also be enlightening for code writing authorities where the illustrations are intended to cover typical conditions, and the pictures themselves may raise questions that are then considered and addressed by the authorities.
Another challenge for architects is how to satisfy the professional responsibility to apply code requirements in those situations where less than full design services are contracted. If contracted services are limited to preliminary phases of design or other design iterations that exclude detailed drawings and specifications, how should the architect account for code requirements in the preliminary design phases, and how should the architect account for code requirements that would normally be applied to the development of detailed plans and specifications? How should the architect alert the owner (and/or contractor) of the need for the owner or contractor to complete the process of code compliance related to parts of the design that are beyond the architect's contracted scope of services?
I recall the advice or direction of one architect employer to make sure that what you do show on drawings is correct. His comment was not really focused on codes, but it could be applied to the question of code compliance in preliminary design. The code requirements to be considered in preliminary design tend to be large scale matters that would govern detailed development of a design in later phases. For example, a schematic design would consider zoning regulations such as building setbacks and building height and also allowable area and height as established by the applicable building code for the intended building use. That would be an appropriate design phase for consideration and documentation of building code construction type. The preliminary code analysis should reveal any applicable requirement for fire walls to divide the project into 'technically' separate buildings, and appropriate locations for such fire walls could be shown diagrammatically on the preliminary plans together with notation referencing the specific code provisions that would govern development of detailed design in a later phase. If it is not practical to even approximately locate such fire walls diagrammatically, those applicable code requirements should be included in notes that relate to the schematic plans. A similar approach can be followed for other code considerations that relate to the preliminary design, such as wheelchair accessible entrances that will require detailed design (e.g., accessible ramps, railings, door approaches, hardware, etc.) in subsequent design phases. Following this approach, each design phase would include code information appropriate to the phase and an indication of further design that is required in a subsequent phase.
One good reason to develop a comprehensive preliminary design approach to code compliance is to lay the groundwork for subsequent design development and documentation that will be performed by staff in the same office or on the same team. Another, perhaps more significant reason, is that architects are sometimes invited to defend themselves against claims of noncompliance where their services were limited to preliminary design and the code matters in question would customarily be applied to a later design phase (e.g., detailed construction documents). While an argument of exclusion by agreement may be valid, the time and cost to wage the argument after the fact may be a greater problem, especially if the project owner has encountered either an unexpected and costly construction change or post-construction change after the architect was dismissed from the project.
One of the reasons that it takes more than a little time to determine the application of codes to a specific project is that codes tend to be dense and voluminous texts that are full of "fine print", numerous exceptions and cross references, and hierarchies that are hard to follow (i.e., "Which article has precedence in this situation?"). Further, the architect is usually charged by statute with the professional responsibility to account for the application of numerous, differing codes - on the same project. In some cases, state or local authorities have adopted parts of different codes that cover similar matters, adding their own hierarchies to interpretation of requirements, and the architects are challenged with having to determine how to resolve gaps and conflicts that have not been addressed by the state or local authorities. Codes that include graphic illustrations of requirements are generally easier for architects to understand, because many - if not most - architects tend to think graphically. In that regard, accessibility guidelines that rely on graphic illustrations have been much easier to follow than text-only codes. Code commentaries or handbooks such as those available from ICC and NFPA can be more useful than the codes themselves due to the use of graphic illustrations. Graphic illustrations can also be enlightening for code writing authorities where the illustrations are intended to cover typical conditions, and the pictures themselves may raise questions that are then considered and addressed by the authorities.
Another challenge for architects is how to satisfy the professional responsibility to apply code requirements in those situations where less than full design services are contracted. If contracted services are limited to preliminary phases of design or other design iterations that exclude detailed drawings and specifications, how should the architect account for code requirements in the preliminary design phases, and how should the architect account for code requirements that would normally be applied to the development of detailed plans and specifications? How should the architect alert the owner (and/or contractor) of the need for the owner or contractor to complete the process of code compliance related to parts of the design that are beyond the architect's contracted scope of services?
I recall the advice or direction of one architect employer to make sure that what you do show on drawings is correct. His comment was not really focused on codes, but it could be applied to the question of code compliance in preliminary design. The code requirements to be considered in preliminary design tend to be large scale matters that would govern detailed development of a design in later phases. For example, a schematic design would consider zoning regulations such as building setbacks and building height and also allowable area and height as established by the applicable building code for the intended building use. That would be an appropriate design phase for consideration and documentation of building code construction type. The preliminary code analysis should reveal any applicable requirement for fire walls to divide the project into 'technically' separate buildings, and appropriate locations for such fire walls could be shown diagrammatically on the preliminary plans together with notation referencing the specific code provisions that would govern development of detailed design in a later phase. If it is not practical to even approximately locate such fire walls diagrammatically, those applicable code requirements should be included in notes that relate to the schematic plans. A similar approach can be followed for other code considerations that relate to the preliminary design, such as wheelchair accessible entrances that will require detailed design (e.g., accessible ramps, railings, door approaches, hardware, etc.) in subsequent design phases. Following this approach, each design phase would include code information appropriate to the phase and an indication of further design that is required in a subsequent phase.
One good reason to develop a comprehensive preliminary design approach to code compliance is to lay the groundwork for subsequent design development and documentation that will be performed by staff in the same office or on the same team. Another, perhaps more significant reason, is that architects are sometimes invited to defend themselves against claims of noncompliance where their services were limited to preliminary design and the code matters in question would customarily be applied to a later design phase (e.g., detailed construction documents). While an argument of exclusion by agreement may be valid, the time and cost to wage the argument after the fact may be a greater problem, especially if the project owner has encountered either an unexpected and costly construction change or post-construction change after the architect was dismissed from the project.
Sunday, March 4, 2012
Change Orders: Making the Architect's Call on Contractor Claims
When construction contracts are based on drawings and specifications prepared by architects, the need for changes during construction raises questions about the completeness, correctness, and coordination of the architect’s drawings and specifications – in short, questions about the architect’s performance. Of course, change orders may also be precipitated by changes that are beyond the control of the architect, like changes in the project owner’s criteria for the project, or some changes in codes and regulations, or other conditions that were not foreseen or perhaps could not have been foreseen by either the owner or the architect.
Regardless of the actual causes of change orders, architects are commonly judged on the basis of “how many” change orders are executed on their projects. Simply quantifying the number of change orders on a project can be very misleading when it comes to gauging an architect’s performance. Given the possible sources of change orders cited above and also the fact that the architect does not have control over the number of change order requests or claims that a contractor may submit or the number of changes that a project owner may request or direct, it is easy to understand that the quantity of change orders is not an accurate way to measure an architect’s performance. Instead, it may be fairer – though still possibly an oversimplification - to consider the resulting cost of change orders that are related to errors, inconsistencies, and omissions in the drawings and specifications prepared by the architect and to compare the change order costs as a percentage of construction cost to those related to other architects’ drawings and specifications on similar projects that are designed and constructed under similar circumstances (i.e., measuring architects against their peers).
Considering the architect’s decisions in response to contractor claims, the American Institute of Architects (AIA) A-201 General Conditions (2007) include the following provision:
§ 4.2.12 Interpretations and decisions of the Architect will be consistent with the intent of, and reasonably inferable from, the Contract Documents and will be in writing or in the form of drawings. When making such interpretations and decisions, the Architect will endeavor to secure faithful performance by both Owner and Contractor, will not show partiality to either and will not be liable for results of interpretations or decisions rendered in good faith.
This requirement for impartiality is also found in AIA standard owner-architect agreements and in various professional regulations and codes of conduct. Yet, given that the architect is typically under contract with the owner and paid by the owner, the architect faces a de facto conflict of interest in evaluating a contractor’s claim for extra cost. Contractor claims are typically related to items of construction that are found to be needed but are not, at least in the contractor’s opinion, apparent on the drawings or in the specifications (“the contract documents”). The challenge for the architect faced with such a claim is to determine whether the needed item is “reasonably inferable” from the contract documents. If the architect determines that the item is required by the contract documents and denies the contractor’s claim, the owner may not have to pay an extra cost for the item, and the owner may be satisfied with the performance of the architect in terms of both the contract documents prepared by the architect and the construction administration services provided by the architect. If, on the other hand, the architect agrees with the contractor’s claim, then the owner may be dissatisfied with the architect on both counts. It takes a different owner attitude to appreciate the integrity that is necessary for the architect to acknowledge an imperfection in the contract documents.
There is no single rule of rightness that applies in every case. Sometimes one party is in the right, and sometimes the other party is in the right, and it is difficult to outline a simple rule for governing these situations beyond the provision of “impartiality” that is established in the General Conditions.
Drawings and specifications may never be perfect, and some would say they never can be perfect. However, drawings and specifications that are complete, consistent, coordinated, and are clear and readable to the extent possible leave less to interpretation; so there is less need for determinations of reasonable inference. With those goals in mind, change orders related strictly to imperfections in drawings and specifications can be minimized.
Another way to consider what is “reasonably inferable” is to ask what a bidder would see (or could reasonably be expected to see) in the contract documents as the basis of a bid (or sub-bid). The question of “inconsistencies” is interesting, because it is not clear that a bidder would actually see inconsistencies in the drawings and specifications that might become apparent to the architect when reviewing a contractor claim. The contractor may have developed a bid based on an interpretation (a complete “picture” of the project, if you will) that considers all of the differing provisions of the drawings and specifications in a consistent way. It is not unusual for the architect to be the one who is befuddled in this responsive review of the drawings and specifications, discovering “inconsistencies” that must now be interpreted in a way that would allow for compliance with a design intent that may not have been clearly conveyed. If it is necessary in the architect’s response to a contractor’s claim to explain numerous contradictions and take exceptions to numerous drawing and specification provisions in order to reach a conclusion that matches the designer’s intent, then the requirement is not reasonably inferable. A less troublesome approach for the architect would be to develop the necessary consistency in the drawings and specifications before they are issued for bidding.
Sunday, February 26, 2012
Planning a Phased School Renovation and Expansion
School renovation and expansion projects are commonly related to overcrowding and/or obsolete facilities. Construction in phases may be the only choice when school operations must continue in the same building or on the same site during renovations and expansion. Phasing needs and requirements should be considered during the design of such a project in order to ensure that provisions are adequate for ongoing school operations during each phase of the project.
Phasing plans and specifications should be based on at least the following considerations:
1. Each phase should provide sufficient classroom space for the enrollment. It may be necessary or advisable to rent or purchase relocatable modular classroom units for use during one or more phases of the project. The actual determination of necessary classroom count should be made by the school authority.
2. Construction areas must be adequately separated from occupied areas.
a. Separation walls may include a combination of existing walls or partitions and temporary or permanent new construction that affords the required fire separation and minimizes dust, fumes, and noise transfer from construction areas to occupied areas[1]. It also, of course, must adequately separate construction personnel from building occupants.
b. Construction fencing should be planned to separate contractor staging and construction areas from owner/user areas, neighboring properties, and public areas (e.g., streets and sidewalks). The fencing layout may need to change from phase to phase.
3. Utilities should be adequate and uninterrupted[2] in the occupied areas of the building. These utilities would typically include heat, lights, power (normal and emergency systems), telecommunications, water, sewer, fire protection and alarm systems.
a. Replacing boilers in a school can take as long as six months, especially if hazardous materials removal is part of the process, so the heating season should be considered when determining project phasing and the feasibility of replacing a heating plant in the existing location. It may be more practical to construct a new boiler room in order to minimize downtime and the risk of delays.
b. In order to maintain existing electrical services, it may be necessary to build a new electrical service entrance and backfeed the existing systems that will continue to serve existing occupied areas[3]. These backfeeds may be different for each phase of a project.
c. Any of the utilities may need temporary connections, extensions, routes, “jumpers”, supports, and/or temporary equipment in order to satisfy the need for adequate and uninterrupted utilities in occupied areas[4].
4. Adequate exits (i.e., egress facilities) must be provided. Exits must be adequate in width and arrangement to meet applicable code requirements. Exit calculations should be performed to determine code compliance. If any existing exits will be blocked by a phase of construction, the remaining exits must be sufficient in arrangement and width to meet code requirements[5], or additional permanent or temporary exits must be provided. Exit signage and lighting must also be coordinated with the exit arrangement for a given phase. Temporary[6] corridors may be necessary to link occupied parts of a building that are separated by construction areas. Protected exit walkways may be necessary to link building exits to the public way and maintain separation from construction areas.
5. Toilet facilities must be adequate to serve the occupied areas of the building. In some cases, this may influence the delineation of phases or the location of new toilets.
6. The need for food service must be addressed throughout phased school construction. Food preparation, service, and dining areas may need to be relocated to accommodate renovation and/or new construction. The challenge is reduced if food is typically prepared in a remote facility and delivered to the school undergoing renovation, but the challenge may be greater if the school undergoing renovation houses the main kitchen for several schools in a district. Can a temporary source or provider be arranged to prepare and deliver adequate meals? And, if the cafeteria itself must be offline for renovation, can an alternative space be used?
7. Athletic facilities use tends to vary seasonally. It may be practical to take a gymnasium offline during the months when physical education and other athletic programs can be accommodated outside. This consideration may influence the phasing schedule such that gymnasium renovations occur during warmer months; and field improvements may need to be completed during summer vacations or planned such that new fields are completed before existing fields are improved or taken offline.
8. Parking must be maintained or provided in sufficient quantity and condition to serve the building occupants. The parking arrangement may need to be changed from phase to phase to satisfy the requirement. Walkways must be included to connect parking areas to building entrances. Parking areas for building users should be separate from construction parking areas.
9. Separate driveways should be planned for building users, school buses, and construction. The typically desirable separation of school buses from cars should be part of each phase, and a separate vehicle entrance to the site should be planned for construction personnel and deliveries.
10. Air intakes must be protected from dust and fumes. Temporary air intake “stacks” may be necessary at building air intakes adjacent to construction areas to avoid contaminants related to construction.
11. Accessibility features that are required for the school facilities must be maintained as part of each phase[7]. These would include, for example, ramps and elevators to the extent required.
Timely phasing considerations are likely to influence a project design in ways that will make construction less disruptive for building occupants.
The requirements related to phased construction should be clearly established on the drawings and in the specifications that will be used for bidding and constructing the project.
[1] Special requirements applicable to hazardous material removal may be more stringent and take precedence over general criteria based on desirable separation. Also, the EPA has published indoor air quality (IAQ) guidelines for school renovation (see http://www.epa.gov/iaq/schooldesign/renovation.html), and states and other authorities have established similar criteria.
[2] Contract documents may provide for necessary, brief or momentary interruptions to occur during power switchovers and similar changes. If they are necessary during occupied hours, they should be scheduled in advance with the building owner.
[3] Local fire authorities typically want to limit electrical services to a single location where power to an entire facility can be shut off in order, at least in part, to minimize risk to fire fighters.
[4] Special attention is warranted where partial building demolition will sever the services or structural support of services between occupied building areas. The bid documents should be clear in requiring temporary support or temporary rerouting of utilities and/or temporary equipment to serve the remote areas.
[5] The applicable code should be studied to determine whether any reduction in egress capacity is allowed, even in the case where existing exits exceed code requirements.
[6] The applicable code should be studied for requirements and limitations related to “temporary” construction. The duration of such construction may be limited by code to less than the anticipated duration of use during phased construction. For example, Section 108 of the 2009 IBC limits a permit for temporary structures and uses to 180 days; yet some requirements for temporary structures are not less than what is required for permanent construction. Chapter 31 of the 2009 IBC also includes requirements for temporary structures and for special construction that may be considered applicable to temporary facilities for phased school construction.
[7] Accessibility requirements would typically apply also to temporary modular classroom units.
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