Modular design in construction is the use of easy-to-assemble components that have been developed off-site to simplify the building process. Modular design and construction equipment have been receiving a lot of positive press recently. To date, the process (also known as off-site construction) has been touted in print and on television as the answer to almost every societal problem, from homelessness to reducing carbon emissions.
While many assume that modular design is the result of technological advances like BIM (Building Information Modeling), the process can be traced back to post-WWII London. Needing to replace over 1 million houses and buildings quickly, local authorities in post-war London embraced modular construction. London remains ground-zero for modular construction, as evidenced by the world’s tallest (43 floors) volumetric modular building, 101 George Street.
Most assume that traditional and modular construction are worlds apart, but both building methods follow the same basic four-step design process:
- Schematic design
- Design development
- Construction documents
- Construction
Of course, the biggest difference between the two construction options is the work location. Building at a modular plant or factory presents several cost-saving opportunities for owners and developers:
- Shorter construction schedules
- Virtually no weather delays
- Lower labor costs
- Minimal on-site material storage concerns
- Less waste in landfills
These benefits are the direct result of an additional step not mentioned in the modular design process described above—the design freeze.
Modular Design and Construction: What Is a Design Freeze?
A design freeze is simply a point within the design development phase when all major project design decisions must be made by a certain deadline, and become “frozen.” In other words, no substantial changes may be made to infrastructural elements such as electrical, structural, mechanical, and plumbing systems and their major components or locations reducing impact from change later on in the building process.
For example, finished plumbing fixtures can be chosen at a later stage in the design process, but the sink, faucet, and toilet locations must be finalized during the design freeze.
The precise locations of registers and grilles can be adjusted or changed to fit tenant requirements. However, the Heating Ventilation and Air Conditioning (HVAC) technology like Variable Air Volume (VAV) or Variable Refrigerant Flow (VRF)
unit locations must be determined during the freeze to allow time for setting up the required electrical and plumbing service connections.
The beauty of modular construction is that the units connect together similar to playing with Legos. The assembly plant builds the units at their physical location, and then they are shipped to the construction site. Since the modular units are nearly 100% complete when they arrive on site, any changes to the infrastructure systems, such as moving a toilet, or adding another mechanical unit could be expensive and time-consuming. As a result, design team members must adhere to the design freeze, or the cost of later changes will dramatically exceed their utility₁. However, since modular construction first emerged in post WWII London, the design freeze has become a critical component of the modular construction industry.
Incorporating Flexibility into the Design Freeze
The biggest challenges for both traditional and modular construction are the ever-changing tenant needs for commercial spaces. Some tenants require only a fresh coat of paint, while others require a major upgrade for the space to work for their business.
Design freeze decisions such as Crossed-Linked Polyethylene (PEX) plumbing lines and zoned Heating, Ventilation and Air Conditioning (HVAC) equipment can simplify future tenant improvement work for a variety of tenants and business models.
PEX plumbing arrives on easily transportable spools and doesn’t require heat and solder like copper pipes. PEX can also be fished through an existing wall assembly without it being necessary to remove the drywall.
Zoned HVAC systems make expanding a suite or moving walls around a much simpler and cost-effective process. Simply add or remove the affected units to the master thermostat control circuit, and you’re done.
In the instance of tenant electrical and cabling needs, raised flooring systems can provide maximum flexibility combined with quick and easy access. Within the 2-3” open space created above the existing slab, there is ample room for all the electrical, data, voice, internet, video, and computer cabling for even the busiest of offices or call centers.
The Gridd Adaptive Cabling Distribution® system, for example, was specifically designed and developed with facilities management teams in mind. To keep up with varying tenant requests, power and data cables are kept readily accessible without a need for demolition if modification is necessary. After removing the finished flooring (typically carpet tiles), our raised floor panels require no special access tools, unlike other flooring systems.
The result is that facilities teams can now quickly change cabling in a commercial space within a matter of days as opposed to weeks or months. Gridd allows businesses to integrate, update, or replace technology smoothly.
Learn more about how Gridd can simplify your commercial raised flooring project.
