I got the opportunity to design some school buildings right out of college. They were fairly large projects taking six months to a year for the design phases. There was lots of time to recover from missteps. After a couple of these I got an admin building for a small school district. By comparison this was a three-bedroom house in scale. Before I had a handle on what the project would entail, I started focusing on the entrance and how I wanted that to work. After a day or two, the question came. "What the hell are you doing?" I explained about the importance (to me) of the entrance. "Do you even know if this is going to be 1-story or two? Does it fit the site?"
This is one of the chapters in my e-book, Trello-PM. I want to give you a glimpse at how you might develop a Project Master Template. It is a great Competitive Advantage using a tool like Trello™. See what you think...
The Extension Offices project has 9,200 square feet on one floor.
The structure was classified Mixed Use Group, A3 and B, and Construction Type 5B, sprinklered, when built in 1993.
Facilities include offices, a community workshop, library with a high density storage system, conference room, work rooms, a demonstration kitchen, and a large community room capable of being divided into three smaller meeting rooms with folding partitions.
Photos and drawings available below...
The Municipal Courthouse project housed three courtrooms, judges’ chambers, Clerk of Courts offices, public and other ancillary spaces in 17,500 square feet on one floor.
The structure was classified as a Mixed Use Group A-3 and B; and the Construction Type was 2C with sprinklers.
Built in 1992.
Notable features are the skylighted lobby and triangular light shafts at the entrance.
Photos and drawings available below...
The Technical Design Diagnostic came to our attention about 1990. Unfortunately we have lost track of its origins - perhaps Fred Stitt?
The concept of the Technical Design Diagnostic is that it is a first step in getting a handle on the project. If your goal is to find the best design that meets your client's program, including budget and schedule, which it should be, then the Technical Design Diagnostic is the most direct way to do that.
The Technical Design Diagnostic also takes less time than a design study that ignores the parameters that will inevitably bring you back to just a subset of what you once thought was possible. We have found that by using the Technical Design Diagnostic, the project design concept becomes very clear in just a few days for most projects.
The Technical Design Diagnostic is intended to be followed one step after the other in roughly the order shown here. When you have thought all these issues through, then you are ready to start designing.
One of the key features of PM-Steps is the use of STEPS. The STEPS subdivide the work of each design Phase into four sets of tasks. Breaking the work of the Phases into more manageable chunks that are in turn arranged in a logical order is intended to provide more control over the performance of the work. One of the aspects of project management that I always found challenging was delegating tasks in a way that kept the process moving forward. Too often the delegation had to be revisited (reworked) when later work showed that the early assumptions were now wrong. STEPS help to prevent that.
The Assembly Concept is a system of categorizing work based on the major components of a building project. This is a useful way of thinking about your project for many purposes - storing typical details, organizing design work, estimating costs, structuring bid packages, planning construction.
The old 16 division (now many more) CSI system with its many sections represents the final work breakdown by individual components. This is helpful when you are looking for completeness or trying to describe, price or specify those components, but in many ways and for many tasks this fine detail is an impediment. For example, a window section in a masonry wall involves Divs 4, 5, 7, 8, 9 for masonry, lintel, flashing, window, and finishes respectively. It is very difficult to think about the window detail in terms of those five divisions, but the detail fits very nicely into one of the Assembly Divisions in this system - Exterior Closure.
This Schematic Design Process has been developed over many projects. But the nature of design is that there are many ways to get to the end result. The benefits of this Seven Step Process is that each step builds upon the last to avoid re-work, which is the killer of efficiency. Use the process to explain to your client why you need information from them now rather than later (to avoid additional design costs for them). Whether you use this process or one of your own making, I highly recommend that you standardize on a methodology that your team can use to anticipate what to do. Even with a standard like this, no two projects will follow it exactly. I think Eisenhower is supposed to have said something along the lines of "The plan is rarely very helpful, but the planning is indispensable." Also, remember to review each step with your client to make sure your interpretations and understandings are on target with their needs. Yes, pesky, but necessary.
Curtain walls have certain advantages. The main one is appearance, followed closely by maximized glass for daylighting. Another advantage is that erection can be done as fast as any other system.
Low-rise curtain wall is different from high-rise curtain wall. The sophistication of the water shedding and pressure equalization are the differences. These details show a low-rise solution.
Some of the key factors to consider about curtain walls are:
In my experience stages fall into two broad categories. Traditional Theater Stage (proscenium, arena, thrust) includes stages that are used for plays, musicals, and dance; and Platforms include stages that are devoted to only speaking, town meetings, video and presenting.
Stages can be designed for a specific purpose, e.g. drama, musical theater, dance, or musical performance; or they can be multi-purpose. Once you pass the limits in the building code for a Platform, there are several 'triggers' for specific requirements. Take a look at Chapter 410 of the International Building Code.
The type, size, flexibility and sophistication of the venue (whether Stage or Platform) is dependent on the function and end user: Amateur/Professional, Primary/Secondary School, University/Professional Theater, Broadway Touring House or Regional Theater. All of these considerations will affect the design criteria much more.
C10-Special Access Handicapped Toilet Room
OVERVIEW / DESCRIPTION
I have been volunteering my time for a non-profit for 30 years. During that time I have learned a lot about accessibility. The first toilet room conversion that I did for the agency was a disaster. The clients are REALLY disabled, and a standard ADA toilet room is barely a good start.
This project converted an office into a toilet room. This became a priority when a reorganization of space created a 75' trip down the hall to get to the rest rooms. The adult clients were going 'walkabout', having 'trouble', or taking staff with them for assistance, which left the program understaffed.
The big takeaway is to look beyond what is being requested to see what the real requirements are.
When I first got out of college, twenty years before the internet, I searched and searched for a description of how to do project management. I wanted a how-to. A checklist.
I never did find one.
About ten years ago a friend, who designs public schools in Ohio, shared this with me. I believe the state architect developed this as a guide to keeping projects for the state on schedule. There are 45 steps in the process. One for every week of the expected duration of the combined three design phases - Schematic Design, Design Development, and Construction Documents.
You will notice that we began making it our own, and you might want to do the same thing. I have included a link here so you can download a Word.doc of the document to help you customize it.
As designers we aren't always comfortable on the site observing what’s going on. But there are good reasons to do it anyway.
First: Most clients like the idea of having their representative looking after the construction work.
Second: We have had the experience of being blamed for screw-ups that the contractor created. Being involved protects your reputation.
Third: If the contractor is shoddy, your being involved could avert unfortunate results. This is good PR.
Fourth: You make more money on every project by including CA.
CA is poorly compensated in most contracts and fee structures. So up front set a limit on the time that is included in your fee. Keep the client aware of how that allowance stands, and alert them when you have to start billing hourly. I lost money on every job until I hit on this solution. I had one client in 15 years balk, but even he begrudgingly went along because he saw the value.
The Construction Administration Phase usually starts when the contractor or construction manager receives a signed contract or a Notice To Proceed [NTP]. No two projects are the same, however the main tasks during this phase are:
Construction Administration Overview
Every time I have used this technique for understanding cut and fill, an engineer has told me "You can't do it that way" or even "That doesn't work". And yet I always get useful information that engineering can't provide. Well, it can provide it but there are impediments. First you need an engineer on board. Second you need a proposed topo to give him to work from. And third you have to convince him to do this several times. Of course all this takes a week to get the engineer on board, a day to create and send the proposed topo, and an indeterminate amount of time to get the revisions. I can use this technique to get a 'good-enough' answer in a couple of hours.
Why do I want to know about cut and fill? Basically I want to know because I don't want everyone to get excited about my fabulous site plan only to learn later that earthwork will cost more than the building. So I want to know that my idea will be defendable. Plus I love this site planning stuff.
I have used several Project Management Tools similar in concept to PlanGrid - Buzzsaw, Project Central, AutoCAD 360, Basecamp... What works so much better with PlanGrid is the ability to easily annotate your drawings inside the app and publish the markups to the whole project team. The markups could be coordination comments to the design team (or client!) in the design phases or correction comments to the contractor during the construction phase. PlanGrid really excels at graphic communications. Site photos are easily integrated into the drawings to enhance the punch list process, too.
Projects are set up on www.plangrid.com and shared to other team members by browser, tablet or phone (which works surprisingly well). Input by team members using a tablet is very easy, so annotations can be done anywhere.
This is the third post in a series that addresses design aspects of stairs. The earlier two posts can be found here and were called Commercial Stair Layouts - Rule Of Thumb and Stair Technical Considerations - Rule Of Thumb. These form the basis for jumping into finish considerations.
When I am working out a stair configuration and basic structural considerations, I find that is it helpful to have a concept of what I want the final stair to look like. This might take a half hour longer during the early design, but it can save you hours of changes later. There are four components of a stair that need consideration - Stringers, Hand Rails, Guards, Treads/Risers.
The reasons that you might consider one material instead of another was covered in the 'Technical Rule Of Thumb' noted above. 99% of the time I use steel for the stringers. If I want the stair to be a focal point or a design feature, I discard the usual channel stringer solution and start to consider using a plate, a tube or a pair of boxed channels. I like the way these structural shapes look. You will need to get your structural engineer involved at some point, but there are lots of ways to get the look you want by varying the structural characteristics of the steel stringer. For instance, a standard 12" steel channel could be doubled up to form a crisp box shape about 3" x 12".
Usually getting the shape you want "overdoes" the structural capacity, as long as you stay close to a 12" depth or more. This same stringer could also be a 2" or 3" x 12" tube or a 1-3/4" x 12" box shape formed by welding a plate to close the open side of a channel. Or keep it really simple with a 3/4" x 12" plate. In all these solutions a key to looking good is to remove (grind off) all mill marks, grind welds smooth, and fill any joints by continuous welding or by using body filler.
Code has lots to say about hand rails, limiting diameter, shape and clearances. Hand rails can be wood, steel, aluminum, stainless steel, or nylon-covered metal. I think wood looks a bit out of place unless your building has a lot of wood trim elsewhere. Steel needs to be painted and the paint rarely stays intact for more than a month. I tend to use a lot of anodized aluminum for hand rails with a hairline jointing system. Stainless steel usually costs more and is harder to get and keep a good finish on. Nylon-covered metal is fairly expensive, but it is the only way to realistically introduce color. I don't like to leave the hand rail mounting brackets up to the contractor's discretion. The wrong brackets will "kill" a lot of design effort.
Guards are another item that the code controls by dictating configuration: height, strength, openness, climb-ability. The choices are pickets, screens, panels, glass, and solid. Before the latest International Building Code was released, which I haven't reviewed yet, the non-climb-ability provision eliminated everyone's favorite solutions - the horizontal rails, cables. This eliminated a lot of descent-looking solutions that weren't terribly expensive. You are left with pickets at 4" on center or jump right into some fairly expensive screens or panels. The screens are made of wire or expanded metal lathe in frames that are made to the sizes needed to fill the guard openings between posts and rails. Panels are similar except mostly solid and made from wood, composites or sheet metal.
The next big jump in cost is to glass. The tempered glass is expensive, and some of the stainless steel posts can take your breath away. Of course you can always put your own system together using epoxy painted steel posts and standard fittings to hold the glass. Unfortunately this usually shifts the cost out of construction and into design where you might not be compensated for your effort to save money. Solid guards are a low-cost solution. You need a steel framework into which to set metal studs and drywall. This solution works best when you can create an interesting shape out of the stair or you just want something without the curse of pickets.
The typical commercial stair has treads and risers made of concrete-filled steel pans. Code may also dictate 'closed' risers. How to dress this up? Rubber and vinyl are the only products that I can think of that are designed to solve this issue. Unfortunately, they don't really offer an up-graded appearance. They are the 'picket-solution' of tread finishes.
Carpet is the old standby and works well. Wood, stone, tile, and other floor finishes need some careful attention. The leading edge of the tread is very susceptible to impact damage or becoming a tripping hazard. Another issue is that a flooring over 1/4" in thickness starts to impact the stair configuration itself and may need adjusted riser heights at the top and bottom. That said, a 1" stone tread is well worth the attention to detail.
If you have gotten this far, you probably fall into one of two camps. First, those folks who can't wait to get their hands on the next stair design. Second, those folks who are sure they don't want to design a stair. I like stair design. It is like a mini-project with all the same considerations as a building without the pesky need to integrate the M/E disciplines.
I've been working on a series of articles about designing stairs. There isn’t any special order to them. The first one was Commercial Stair Layouts Rule Of Thumb about a month ago.
The technical considerations I’m talking about are selection of materials, and structural detailing. Here is how I usually proceed. The vast majority of buildings we have designed are Type 2B, which back in the day was known as “unprotected non-combustible”. That ’non-combustible’ part all-but-eliminates wood stairs. But other issues that work against wood are the width of stair required in non-residential buildings and the difficulty of joining the members structurally. It may sound odd but it is much simpler to build a steel stair. The standard joining methods scale up very nicely in steel; not so much with wood. This leads to not only more difficulty designing the stair but also building it. The perceived savings by using wood quickly disappears.
We can dispatch concrete stairs by simply saying they work great, easy to design and, unfortunately, require lots of skilled carpentry labor to construct. This prices them out of reach for most budgets.
Steel is the workhorse when it comes to commercial stairs. You see them everywhere - confirmation of their fitness. You may have also noticed that they can be ugly.
The typical exit stair is made from channel stringers, a concrete-filled sheet metal pan resting on angles fastened to the stringers. The railings are steel pipes with steel bar pickets at 4" o.c. It can get rough. But there are several things you can do to improve the looks. These are simple and well worth the effort and cost if the stair isn’t completely utilitarian.
A couple of other tricks that improve the appearance of stairs are:
a) adding a little width to make a more gracious appearance;
b) holding the descending riser back one tread on a switchback stair so the handrail can make a smooth transition;
c) splay the stringer(s) at the bottom for a spartan version of a Renaissance flowing stair;
d) use the strength and workability of the steel stringers to ’suspend’ and display the stair.
Once you are conversant with the detailing and code limitations, push the limits.
If you are ever in Las Vegas, check out the stairs in the high-end shopping venues to see how you can make the stair into an art object! Sounds like tax-deductible research to me.
Stair Finishes are considered here.
So here is how Construction WorkZone works.
Register for free to look up 10 items; or sign up for monthly use - $.99/first month, then $3.95/mo., cancel anytime.
The data search looks like the screenshots below.
The localized cost modifier seems to be a constant percent when I spot checked it. So you could do that just once on your subtotal.
The key features of cost estimating don’t require exact unit costs, which don’t exist anyway. Just look at the bids you receive for proof.
SUMMARY - PROs
Lots better than guessing
Low learning curve
SUMMARY - CONs
A little more time-consuming than I would like
Must transcribe costs, which is error-prone
Results not saved for you (so take screenshots??)
A system for storing our standard and typical drawings has eluded us for years. After all, the real promise of Computer Aided Drafting is saving time by not having to draw the same thing over and over. Everybody wants that.
What this has amounted to for us is scavenging details by cut and paste from one project to another. Everyone has their preferred sources that they have worked with in the past. Standardization implies “perfected over time”, but scavenging implies “re-used as is”. There’s a big difference.
For the longest time we tried to make the CSI 16 Divisions work as the filing system. This was very unsatisfactory. Then we hit on UNIFORMAT assembly divisions and found that it worked great for the filing system. The only problem was that it took too long popping open file after file looking for appropriate details.
Finally we came upon the concept of storing the details of each assembly in its own sheet of drawings. That minimized the search to opening just one file and panning around. This guide below was placed in the folder with all the standard sheets of details as a reference.
Most recently we hit on an improvement to this method of storing and retrieving standard and typical details. And that was to store the details in a template drawing that would actually be used in each project where its contents apply. The process was to simply copy the whole .dwg file to the current project folder; re-name the file; 'viewport' the applicable details; and add custom work as needed.
EXAMPLE: In a template sheet named “A-50b-InteriorDetails” collect all your drywall, masonry, casework details, etc. These are in Model Space. The “b” in the name is a placeholder for the actual sheet number when you know it. If any of these details are ALWAYS used, say a standard drywall partition detail, place it in a viewport in the Sheet view. On the next project that comes along, copy the file to the project folder, ’viewport’ any other details that apply, and then continue as always.
You can get a jump on this sheet template system by assembling good examples from past projects to use as your templates. Delete the non-standard stuff and you are ready to go. Add in other standard details as you find or create them. In about a year you will have a very nice addition to your firm’s intellectual property that will continually pay dividends.
We haven’t completed the transition from the system shown above in the image to using template drawings. However, we think the templates hold a lot of promise because even a Site Plan, which is always unique, could have a template sheet populated with items that will be needed: north arrow, legend of line types and symbols, paving key, standard boilerplate notes, etc.
Are you inspired to start saving time on the mundane stuff so you can spend it on Design?
Most projects are not the work of a single individual. There are many roles that need to be filled, and it is the unusual project where all the roles are filled by one person. Civil, geotechnical, structural, M/E engineering are just a few of the obvious ones. When the project has a Design Team, complexity builds and it is important to think about how you will simplify things for everyone. Below is a checklist of all the issues we have identified. You might have others to add or some to scratch off. In any event, when you kick-off a project, it helps to have a detailed discussion of specific roles and responsibilities. The success of the team depends on it.
ROLES AND RESPONSIBILITIES
Similarly, the Design Team should consider a number of issues relating to the Client/Owner. Communicating and working with the owner needs to be managed congruently by the entire team by addressing the following issues:
My experience is that you will never get all of these issues aired; but it is better to try and learn what you can before it bites you.
Every project faces 6 key issues. They are Needs, Character, Context, Constraints, Schedule and Budget. You will need a good understanding of these six because the goals for your project lie in these six areas.
Needs encompasses spaces and the types of spaces you require. Part of this issue is also the relationships that these spaces should have to one another. Specific functions that you need to accomplish are part of this issue:
- area of spaces
- types of spaces
- relationships among spaces
- special functions
Character includes non-spatial issues and some of these are immaterial as well.
- appearance of exterior and interior
- green initiatives
- building systems
Context considers the environment in which your project takes place. Whether you are considering a free standing building, an addition, or a remodeling project, there will be issues arising from the surroundings of the project.
- location /access
- availability of utilities
- orientation (solar and wind)
- shape and size of site
- available transportation
Constraints are the limitations and restrictions that you will encounter. Some are universal, but most are specific to you and your context.
- building code
- environmental regulations
- permissible contract styles
- parent organization processes
- source of funds
- stakeholders' desires
The schedule issue is part of many endeavors. However, most projects have schedules that consist of innumerable tasks within four broad phases before occupancy occurs.
The issue of budget is the most crucial issue for the majority of projects. The budget has income and expense sides to the issue. In a general way the whole project is usually an attempt to match the sources of funds with the expenditures that the other five key issues prompt you to make. The costs fall into 2 categories - hard costs and soft costs.
Hard costs are:
Soft costs are:
- other services
- interest expenses
You will find that you return to these six issues over and over. Some resolve themselves fairly early in a project, but others, for example Schedule and Budget, will require attention right up to occupancy of the project.
Poor building acoustics can really undermine a good design. I think there are only about five rules of thumb to keep that from happening.
Building Acoustics 101
Thanks to Hollywood everyone thinks sound absorbing materials like you find on the walls of a recording studio are what makes the room soundproof. The fuzzy stuff on the walls of a recording studio is to kill reflected sound. It doesn't keep sound out - or in. What’s inside the walls, ceilings and floors does that, along with sealed doors and windows.
When you want to limit sound from getting in or out of a room, you need to eliminate sound transmission paths and make the enclosing structure dense. The dense-ness can come from brick, PAINTED concrete block, glass or extra layers of drywall. Glass while great at stopping sound needs extra attention around the perimeter. The typical aluminum framing has numerous gaps through which sound can travel. Concrete block is dense but porous; paint seals the pores.
Commonly overlooked sound transmission paths (air paths) are walls that are not sealed to the floor or roof above, walls that are not sealed to exterior walls, and floors that are not sealed to exterior walls. Contractors love to stop walls 6" above the acoustical ceiling. Without some other measures to stop the sound from just going over the walls, you might as well have cubicles.
The nature of building acoustics is that it is generally easy to make a room less noisy - add some fuzzy stuff. It is much harder to seal sound out of the room if it wasn't addressed during construction.
Even the ideal room enclosure for keeping sound transmission to an inaudible level can be undermined by building utilities -
Ducts often act like a sound conduit as well as an air conduit. You need sound baffles to eliminate sound traveling through the ducts. Three right angle bends in lined ducts that travel between rooms will make a big difference but it won’t stop loud noises without baffles.
An under-appreciated solution to sound privacy is a white noise system. White noise works great because it creates about 50 decibels of noise in the same range as speech. However, a lot of people object to the white noise solution initially, but within two to three weeks they will never think about it again. The real downside to white noise is its green-ness. Its not very green. It is more stuff that has to be manufactured; and, worse, powered all day long. The opposite of green.
A great way to get an education in acoustics is to hire an acoustical engineer for a sensitive project and ask him a lot of questions. That's what I did.
The most common type of crane that we have dealt with is a bridge crane. These cranes have spanned bays as wide as 80' and had hoists rated for lifting 20 tons. A 35' (or taller) building is often needed in these circumstances. These cranes travel most, if not all, of the length of a bay of a building, the crane bay.
The main components of a crane assembly are: footings, columns, crane beams, crane rails (like railroad rails only lighter weight), crane bridge, truck, and hoist. Each of these components has its own considerations.
The columns - often separate columns are used to isolate vibrations and bending caused by crane beam brackets. X-Bracing may be required.
Structural capacity of crane beams needs to limit sag and camber can be a problem too. Either can stress the trolley carrying the end of the bridge and in extreme cases causing it to become stuck.
Welding the crane rails to the crane beams is not desirable for long crane spans or heavy cranes. J-Bolts seem to work best and are easy to adjust.
OSHA has clearance requirements at ends of the bridge span and above the truck and hoist.
Electrification of the crane is accomplished by festooned cable or buss bar. The electrician supplies power to a point along the crane beam for hookup by the crane erector.
Height to the crane lifting hook is the vertical criteria around which clearances and structure are worked out. Clear span or horizontal travel of the hook determines the width of the bay or building. It is rare that the hook needs to get to the edge of the specified clear width.
Take care with roof drains, exh ducts, or plumbing vents that there is a path for each of them that respects the required clearances.
Often lighting levels need to be high in a crane bay used for assembly work. The vertical clearance can make this a challenge. Consider portable floor set mobile lighting. It may provide better light where needed rather than trying to light the entire crane bay to 70 fc. If feasible this could reduce energy use and provide better lighting.
Get the Owner's crane supplier tied down early so coordination doesn't cause construction delays and extras. Not all cranes can fit as intended if the building design is determined without the crane specs.
Occasionally we have worked for the contractor instead of the Owner. Lots can go wrong in this arrangement, but with the right firm it can also work well - for everyone.
One of the things that might be different working for a contractor is that they may have specific requests for how they want information shown. We rarely use a sheet size other than 36x24. This determines the placement of a lot of information. Considerations like this ignore the user of the drawings.
One of my favorite contractors is the third generation in his family's business, usually a bad omen; but he is more hands-on than almost anyone I've come in contact with. For an office addition for his (our) industrial client he had a very clear idea of how he wanted our work laid out on the drawing sheets. See the image.
His instructions were: "Get both floor plan and ceiling plan on the same sheet along with door and finish schedules so everything is together and I don't have to flip back and forth when I'm working with my subs."
As you can see, it worked out very well. Although, compliance with the National CAD Standards was shot all to hell!
The issue of 'reception' has changed from a typical function for every office-based business from corporate headquarters to DMV clerk to a begrudging necessity for those who can't eliminate the receptionist. Baring elimination, combining job functions becomes the next step. Some of the solutions are to use a security person to also greet and direct people, or place a clerk or secretary at the reception counter.
If you find that a reception counter is needed, the first decision is to determine the full role of that person. From that determination, the next step is to decide on the size of the station and the height that is desirable. Rarely is the reception counter 36" high because this would require the clerk to sit on a stool; or, if the clerk side is 30", then the client is looming over the clerk. The stool or the 'looming' is always a deal breaker. 30" is always desirable for the clerk side.
The degree of customization is always an early decision to resolve. Systems furniture can provide both customization and changeability. Haworth and Herman Miller offer very attractive systems solutions.
In a prestigious setting where interaction with the receptionist is brief, a desk or table (with modesty panel) is a good solution. Telephone reception is the only other job function that is easy to combine with this station without ruining the effect. Because of that, the 30" reception counter is used less and less, except for any portion of the counter that needs to be accessible per ADA.
The more common solution is to provide a 30" counter height on the clerk side and a 42" high transaction counter on the client side. (See this Detail) The 42" height offers decent screening for the equipment and cables that would otherwise be exposed to view and tinkering. The transaction counter works best if it is 14" deep, which allows paperwork to be easily handled. A two or three inch difference between the edge of the transaction counter and the base board prevents the client from kicking the counter as they move close. This recess can be provided in the toe space or in the overhang of the transaction counter or both.
One other configuration that can be used is a raised platform on the clerk side. A 12" high platform places the client side at 42". This creates a comfortable eye-to-eye arrangement with the clerk seated at a 30" counter and the client standing. (See example)
The finishes of the counter can be almost anything - plastic laminate, solid laminates, solid surface material, wood, stone, etc.
A few other things to consider are the flooring that will get the most wear at the clerk stations, electronic equipment placement and wiring needs.
You might also consider an unmanned station using a flat screen display for greetings, logo, company news and a CCTV link to a behind the scenes workstation(s). Years ago Fidelity Investments used a kiosk for guests at one of its regional offices. You logged in and were directed to the appropriate floor where you were greeted by an escort. I think that is what the future reception process will look like.
Hey, I'm Rick Wolnitzek and Architekwiki is my blog for sharing what I've learned practicing architecture for ... a long time. Enjoy!