Mid-rise and low-rise: The unassuming buildings you ignore every day

Part 1: Inside the maze-like hallways, confusing access areas and stairwells, void spaces and other puzzling features that hamper operations

July 28, 2022 02:16 AM •

Mid-rise and low-rise structures are popping up in every growing city. Cities that never had any building taller than a two-story residential structure are now experiencing an entirely new type of fire response – and many organizations simply don’t know what they could face on these runs.

In my experience, too many departments, company officers and crews are ignoring the very presence of these new mid-rise and low-rise buildings, not to mention their building features and construction methods, plus the unique challenges that come with them. Many don’t even have a plan for an event in these buildings. Some officers think they are simply going to approach it like any other structure fire, while others mistakenly believe they can approach it like a high-rise event.

The engine or truck company drives by these buildings every day on the way to the grocery store. Someone in the backseat might say something like, “We should go do a walk-through of that building.” That is usually the extent of the conversation before someone breaks out the grocery list or sales ad as they pull into the grocery store parking lot.

Many mid-rise residential buildings have a center courtyard. Many courtyards can be found on the second- or third-floor rooftop of the parking garage. In these photos, the courtyard is located on the rooftop of the second-floor parking garage. Our main concern in these types of buildings will be access. With units on both side of the hallway, there will be no ladder access from the courtyard. You will not be able to get a 35- or 50-foot ground ladder into the stairwell. You will need a backup plan for any rescues above the second occupiable floor.

These crews are in for a reality check when facing a fire event in one of these buildings. Access issues, multiple levels, huge void spaces, sometimes entirely useless lobby entrances, and multiple points of entry that rarely take you directly where you need to go are the norm for many of these buildings. Many of these residential buildings have long, maze-like hallways that crews must traverse while fully geared and carrying any assortment of equipment. Some of these residential mid-rises and low-rises may have a footprint that spans four to six city blocks long and two city blocks wide. Add premium security measures to the mix, and access will be a major factor affecting your reflex times once on location. The variations with these buildings are limitless.

In this article, we’ll cover several critical factors: mid- and low-rise buildings definitions, building construction appearances and types, and construction features and materials. Part 2 takes us deeper into operations, covering standpipes, fire attack options, attack packages, building systems, and communications.

Defining mid-rise and low-rise

Before we go any further, you might be asking yourself whether you have any of these new low- or mid-rise structures in your first due. What exactly constitutes a mid-rise or low-rise, and what determines that building’s category?

There are several factors at play with the categorization of these buildings. The NFPA has its definition, and the builders have their definition, and a city may have its own definition as well. For this article, a low-rise is three or four stories, and a mid-rise is five stories or taller, up to 75 feet (roughly 7 stories). Either could be residential, commercial or mixed use in nature.

Honestly, it doesn’t really matter because the required life safety features of any new mid-rise or low-rise will be very similar. Most newer buildings will be required to have alarm systems, sprinkler systems and standpipes. Features will also depend on the jurisdiction having responsibility for building codes. Both building types could have elevators and Type l stairwells. This cannot be said with any confidence regarding older buildings of the same heights.

A story of frustration

Appearances can and will be deceiving with these buildings. I once responded to the dispatched address and by all appearances, I was at what most would consider the front of the building. It wasn’t. In fact, there was no “front of the building.” Occupants entered the occupiable spaces through the multi-level parking garage or another elevator that also served a grocery store on the ground level. There was also a small parking lot, a store front lobby entrance, and an elevator in view through the double swinging glass doors.

Some mid-rise buildings will have lobbies that are no more than access to a leasing office or mailroom with no access to the rest of the building.

I looked around for a minute or two and could not locate a Knox Box for keys. After a few minutes of frustration, I decided to use through-the-lock forcible entry. We removed the cylinder and made entry into the lobby. The lobby led to nowhere. The elevator in the lobby required a key-fob to access its controls.

Some mid-rise buildings will have the same systems you find in a high-rise building, but many mid-rise buildings will not have much more than a residential panel.

A minute later, the engine company came from around the corner with the keys and key fob they retrieved from a Knox Box located near an exit stairwell on what would have been considered the Bravo side. The key-fob opened the elevator door and we piled in. Looking at the elevator panel, it only served the second floor of the leasing office. We all exited the elevator and walked back around to the B-side exterior exit stairwell and started making the climb.

As we walked, I was frustrated and voiced my frustration (some profanity may have been included) at the design and planning of this particular building. What we discovered was, access to the occupiable areas had to be gained either through the parking garage, the grocery store or the B-side stairwell, and then you could access the elevator that served the other floors, but not through the lobby like we typically experience.

The buildings

These buildings can be Type l, ll, lll, lV or even any hybrid combination thereof. They can have a formal fire control center (FCC) that includes an addressable alarm panel, printer, keys and elevator recall panels, or simply have an alarm panel that resembles a residential touchpad located on a wall in the lobby.

The lobbies in these buildings vary widely. They can be quite elaborate and allow easy access to the rest of the building or extremely minimal and offer nothing but frustration and disappointment and, as was the case with the aforementioned scenario, deny access to the rest of the building, as it is nothing more than a leasing office.

Most of these buildings will have staff during normal business hours, but after business hours and on weekends and holidays, there may or may not be a contracted security guard on the premises, and that guard will often have zero formal guidelines and really be of little help.

Some commercial mid-rises could, by all appearances, be confused as a small high-rise inside. Tactically, however, one would be greatly mistaken to approach these buildings with a rigid mindset for high-rise operations. One example: setting up a formal lobby control for a mid-rise that doesn’t have a formal lobby at all.

Construction features and materials

From the exterior, many mid-rises and low-rises look like Type l and Type ll construction, and with sprinklers, some might assume that there’s no real threat of a significant fire. This is a huge misconception.

I once watched on TV as a department responded to a mid-rise fire that started as a small fire in a flower bed (cigarette and mulch) and ended up destroying a new five-story hotel. This building had sprinklers and alarm systems, and the fire department was on scene well before any real fire spread occurred. Construction features (large void spaces) building materials played a huge factor in concealing the fire and allowing for a quick and undetected spread once it found enough fresh air.

100_4013 (1).JPG — Construction materials and methods in mid-rise buildings can be any combination of hybrid material. Mid-rise buildings can fall in any category of fire resistance I-V, depending on what the city of builder wants.

Regarding these buildings, planners, developers, construction companies, the city itself, building inspectors and even the fire marshal at times all seem to be conspiring against us. Where am I coming from here? When a developer comes into town with their grand plans for a new mid-rise, they seldom take into consideration the department’s staffing, training, equipment or capabilities. I mean, really, if you’re building a Type lV building six stories tall that spans several blocks, how hard can it be to take apparatus access into consideration?

In the area where I work, several mid-rises are under construction. Most of them are being constructed atop two-, three- and four-story parking garages, and all the residential mid-rises have center courtyards with swimming pools, dog parks and picnic areas. If you didn’t catch that, the courtyard and first occupiable level of residential units are on the roof of the parking garage that could already be three stories high. These buildings have center hallways around the entire building with units on both sides of the hallway, meaning you have units with windows or balconies that face the street side and units with windows and balconies that face the courtyard side. If a fire was to occur, the occupants facing the courtyard who are forced to their 4 x 8-foot balconies would be dropping babies down to other occupants below and looking for enough sheets to tie together make their escape and hoping for a crew with a ladder. Think about this for another minute: A crew given an order to perform rescues from the courtyard will first have to navigate through and up a three-to-four-story parking garage with their ground ladders before making it into the courtyard. I don’t care what your T-shirt says, that is going to take time, plus a lot of communication, coordination and physical effort. However, we must plan for it and potential alternatives.

Void spaces seem to be a very common issue with these buildings as well. Builders will create a void space simply for aesthetics. I have seen void spaces in these buildings that you could park a small SUV inside.

From the exterior, many mid-rises and low-rises look like Type l and Type ll construction, and with sprinklers, some might assume that there’s no real threat of a significant fire.

One additional construction feature that is very harmful to our cause but seems very popular with builders at the moment is the exterior material being used, the cladding or the façade. It’s a type of polystyrene panel wrapped in lath-like material and then covered with a thin layer of a stucco-type surface on the exterior. These panels have a few different product names and are also considered a type of insulation. The panels can be delivered as a finished product, or the builder can finish them on-site. Please take the time to Google this – and start paying attention to any new buildings going up in your own territory.

Polystyrene is not limited to just panels. It also comes in the form of blocks used to construct eaves, parapet walls and decorative corner pieces. It can literally be shaped into anything the builder requests and then simply affixed to the building’s exterior framework. They can even shape gargoyles. Imagine a flaming gargoyle falling from the top of the building as you arrive.

The key here: Polystyrene is extremely flammable and puts off an obnoxious amount of heat and byproducts when burning. Add a small fire that makes its way into the large void space with a polystyrene-type material, and you have yourself an extreme fire event in a matter of minutes (think Grenfell Tower). This was exactly what occurred in the case I mentioned earlier, and there have been many more examples since.

Our current concern regarding mid-rise buildings is the exterior cladding. Polystyrene is a highly flammable yet remain a very popular building material. In a finished building, what looks to be a Type I or II building could really be a Type V building wrapped in this material – not a good combination if the fire starts in a large void area, as fire will quickly extend beyond the cladding to structural support members.

Regarding the footprint of some of these buildings, everyone needs to slow down before bailing off the rigs. It is inefficient, not to mention unprofessional, to enter these buildings and not know where you are going. Even more unprofessional is having three to four crews in tow and nobody knows where they are going. Even worse than that is entering through a useless lobby only to find that the closest stairwell to the fire is in the Charlie/Delta corner two blocks away. You’re in for a walk now.

Newer mid-rise and low-rise residential buildings will have multiple stairwells as required by law, fire codes and ordinances. Having all crews stage and allowing the initial-arriving crew to act as a recon unit is the preferred option here. When the recon crew has determined where the fire is and the best access point, they can then relay this information to command, and all units would then report directly to the closest usable stairwell to the actual fire unit. This will help eliminate having crews walking around randomly in such large buildings looking for the fire. Also, this reduces the physical effort that would be placed on the crews carrying equipment needed for the attack.

In-depth operations

Here we’ve covered the building basics and unique features that you’ll face. In Part 2 we’ll shift to operations – standpipes, fire attack options, attack packages, building systems, and communications.

Stay safe! Get out and train!