As cities continue to grow and populations increasingly move into more urban environments, the need for development in these areas will increase. Unlike rural or most suburban locations, construction in urban markets comes with added challenges that contribute to project costs and schedule for completing work. Choosing the right contractor with knowledge about the complexities of urban development and with preconstruction solutions to deliver your project on time and on budget is crucial.
As a high-rise builder, we want to share the top 6 challenges we have seen companies face.
1. Public Safety
Worker and public safety is our ultimate priority on all construction projects, and in a condensed, urban environment, maintaining top safety standards is a challenge that must be met. Site considerations for public safety accommodations include:
- Secure site fencing
- Covered pedestrian walkways, such as Pac-Van’s modified shipping containers
- Safety netting for both worker fall protection and debris containment
- Clear ingress and egress signage
- Clear working hours and notifications to the public regarding excessively noisy activities
- Maintaining accessible routes for the disabled community
In very large cities, the amount of construction that takes place and the covered walkways that result has been a bone of contention with residents. For instance, in New York City, there is cumulatively three hundred miles of pedestrian protection in use. The need for pedestrian routes through construction areas has even sparked a new business, known as the ‘Urban Umbrella’, which makes covered sidewalk structure pleasing to the eye and user-friendly for pedestrians.
2. Site Logistics
Urban construction sites tend to have little to no space between the lot lines of the site and the placement of the building. This ‘zero lot line’ situation makes construction logistics especially difficult. The following are crucial site logistics that need to be considered well in advance to avoid costly delays:
Construction office location
Street and/or sidewalk closures
Existing and new utility locations
Site ingress and egress
Erosion and sediment control
Emergency meeting areas
Delivery and loading zones
With little to no room outside of the building footprint, a great amount of consideration goes into each one of these factors. In some instances, we have leased vacant lots nearby for crew parking, equipment and materials staging and jobsite offices. When dedicated parking for the crews can’t be achieved, workers utilize street or paid lot parking or use alternate transportation methods.
Delivery and loading zones are another crucial piece of the site logistics puzzle. Project managers and superintendents must extensively plan for materials to arrive just-in-time without any need to be staged before install. Delivery zones may be limited to the street, which means coordinating with local jurisdictions and traffic control vendors for street and sidewalk closures to accommodate this traffic.
Ingress and egress is also a challenging consideration. Many urban jurisdictions have extensive rules and regulations related to street and sidewalk closures and points of access are often limited to a single street. Coordination of trades to accommodate traffic coming in and out is required to maintain traffic flow both on and off the site.
There can be legal ramifications related to site logistics, as well. For example, large tower cranes may infringe on the airspace of neighboring properties, potentially requiring an airspace easement or special licensing agreement.
We know there are nuances that are particular urban developments. Our deep experience in a wide array of industries in urban markets will translate into data points and comparables to ensure a solid and successful project from the ground up.
3. Neighboring Properties
Maintaining neighboring property, including shoring and temporary protection measures, as well as limiting noise, dust and vibration are big components in constructing urban, high-rise buildings. New projects may be within inches or feet of existing structures. In some cases, the foundations of neighboring buildings may be found to encroach into the new building’s footprint, an aspect that may not be known during the design phase.
Particularly when new construction includes underground stories, supporting the foundation of the neighboring structures can add significant cost and time to the project.
4. Local Jurisdiction
Jurisdictions across the country vary in terms of rules and regulations, with every site location likely under the authority of multiple agencies. The different layers can include the city or county, the local water bureau, Department of Environmental Quality, or local transportation agencies. In addition, projects fall under a mix of local and national regulations.
In the City of Portland, Oregon, some local jurisdictional rules include:
- Rules related to street closures, which include accommodating ambulance routes, closure moratoriums and pedestrian access to walkways
- Coordination with the Portland Bureau of Transportation for railroad impacts.
- Stormwater discharge considerations through Cleanwater Services
- Coordination with local utility companies for temporary shut-downs and tie-ins
- City of Portland codes and land use regulations
5. Construction Practices
The riskiest component of most construction projects is the sitework, and urban construction is no exception.
The site logistics, utility installation and connections, building foundations and the first 1 – 2 floors are the most challenging part of high-rise construction. The foundations of each building may include driving piles, tie-backs, underground retention ponds, all while coordinating with the local jurisdiction to tie in power, sewer, water and fiber. Underground work may even include re-rerouting public utilities to accommodate the building and still maintain use of each system.
Protecting the finished materials as the building progresses can become a challenge and requires significant coordination. In high-rise construction, the lower floors are finished ahead of the upper floors. It’s possible to have a lower floor that is completely finished while the upper floors are still only a steel structure with a slab. Because of this, a variety of trades will need to be onsite at any one time, and interior finishes may be complete before the structural tradesmen are done above them.
As the upper floors are being constructed, the lower floors are being finished, so coordination of the trades to avoid collisions or damage to finished product is imperative. The building skin, or the exterior envelope of a building, might be most important in a multi-story building where access is exceedingly challenging once complete. The skin must be watertight and meet building codes for energy efficiency while providing things like sunlight to inhabitants of the building. Sometimes, windows are operational. The skin must be installed from the bottom up, often in pre-fabricated sections for ease and speed of installation.
Building components of a high-rise are complex and all moving parts must be considered in advance. For instance, multi-story buildings contain a ‘core’, typically made up of elevator and utility shafts, with restrooms and lobby spaces directly adjacent to the core on each floor. The remainder of the floor plate is dedicated to the individual needs of each tenant.
6. Tenant Improvements
Interior construction on occupied spaces requires a higher level of attention to project logistics and service to tenants. There are significant obstacles in completing work inside an occupied space, which is a bigger challenge when located in an urban high-rise. Some of the factors that make this work specialized include:
- Noise, dust and contaminant concerns for adjacent tenants, either beside, below or above the space.
- Access to common-use elevators, including protecting existing finishes, avoiding non-construction personnel and leaving the space clean after use.
- How to remove debris or load materials into and out of the space. Tactics may include packing materials up and down stairs, debris chutes out the side of a window, or crane lifts.
- Utility tie in’s and/or shut-downs and the possibility that construction work may disrupt service to adjacent tenants.
Construction teams must be polite to tenants, extra cautious about safety procedures and thorough in their planning to avoid disruption to other occupants as much as possible.
Urban construction and multi-story buildings certainly present additional, multi-faceted challenges. The added complexity of increased public safety combined with a tight site, little or zero lot lines and jurisdictional requirements all add to the time and cost of these buildings.
Inherently, construction is risky business, but with proper planning, all challenges can be overcome. The ultimate key to success is a thoroughly designed pre-construction plan that covers logistics, scheduling, and identification of site-specific challenges, along with a diligent general contractor capable of managing ongoing and unexpected changes with a solution-oriented attitude.
If you’re considering an urban construction project, connect with us here to further discuss your options.