McKenzie Apartments is a 450-unit residential tower in downtown Seattle, with seven floors of underground parking, and first floor retail/commercial space. Resident amenities include a rooftop deck with cooking, bar, and lounge spaces, a pet terrace, community and conference rooms, exercise facilities including a yoga studio on the sixth floor, spa, steam room, and a sauna.
McKinstry provided fully integrated, design-build services for mechanical (with sheet metal fabrication), electrical, fire, and data for the shell and core, while our engineering team designed the tenant improvements for the retail space (Wild Ginger).
Though the building is not currently pursuing a LEED® certification, McKinstry provided documentation and engineering calculations for rebates through Seattle City Light and provided commissioning support. During preconstruction we provided energy modeling and design services.
Mitigating Design Bottlenecks
Early Design Engagement
Demand for unique design in luxury residential buildings is both common and critical, and multiple design teams are typically used to maximize building recognition and interior appeal. Design uncertainty from shell and core teams and interior teams was causing delays and bottlenecks during design. Due to delays, much of the detailing work went unfinished, causing additional onsite delays due to constructability issues. Because of this, trades couldn’t be utilized to their full potential, and they couldn’t perform as needed to meet the project’s schedule .McKinstry stepped in to complete detailing work to get CDs released quickly, while catching and resolving system misalignments that prevented costly onsite mistakes, material waste, and unnecessary field labor costs.
Creatively Condensing in an Urban Environment
Due to the site’s location in a highly-congested area, McKinstry needed to overcome challenging site logistics. Extensive planning, prefabrication, kitting, and close trade coordination mitigated trade stacking and delivery issues. In order to maximize cost savings, bulk material orders were placed and shipped to McKinstry’s massive fabrication shop for assembly and storage. Our manufacturing mindset allowed us to prefabricate plumbing systems for three floors at a time, kit them, and send only the systems needed onsite for connection by onsite teams. Plumbing and connections to FCUs were kitted for simplified onsite installation.
Ensuring Quality through Phased Construction
Mock-Ups for QA/QC
Ground-floor mock-up units were created to sign-off on final design before the final units were built. Significant changes were made to the mock-up and reflected across the building. These mock-ups were also used to sell the units before building completion and offered safe access to see building design during construction.
Leveraging EVT for Labor Productivity
Due to major unforeseen design issues with the shell and core design team, the detailing budget had significant overruns. However, due to our robust EVT tracking, we were able to track labor at the micro level to ensure we were maximizing onsite labor dollars. Due to this high touch approach to labor productivity tracking, we were able to achieve field labor hour savings to balance the detailing overruns.
Mechanical Project Details
Residential heating and cooling was provided by 2-pipe chilled water vertical fan coil units with electric resistant heat and a unit mounted thermostat. Chilled water was provided from air cooled chillers located on the roof of each tower. Besides the residential units, chilled water was provided to the corridor air handlers, lobby area horizontal fan coil units and a vertical fan coil unit located in the sales office. Additionally, chilled water was stubbed into the retail area for future use.
Supply air in the residences is a combination of ducted and un-ducted supplies depending on each unique arrangement. Return air is at the return grille in the lower panel of each vertical fan coil unit. Outside air was provided via trickle vents supplied by others. Toilet, whole house, kitchen and dryer exhaust was routed to the building exterior in sheetrock soffits. Exhaust air terminates in the back of exterior louvers.
Plumbing scope included installing condensing gas-fired domestic water boilers, hot water storage tanks, hot water circ pumps, domestic water boost pumps, sand/oil separators, sump pumps with controls, backflow preventers, lobby restrooms (water closets, lavatories, mop sink, drains), all drains including overflow drains routed to rainwater collection sumps, water piping to in-slab PEX, residence plumbing fixtures, and waste/vent/water stubs serving residential and future retail space
We installed water piping into the floor slab prior to the concrete floor (pointing the pipe upward at termination points). By saving valuable site space traditionally consumed by water piping, we were able to increase productivity, minimize site waste and were able to better sequence mechanical work.
In-Wall Vertical Rough-In Before Framing
Mechanical teams prioritized installing in-wall piping prior to framing, which allows for schedule compression. Drywall contractors work around our piping using two, micro-studs instead of the traditional stud. The benefits allow for more efficient sequencing, early-start installation, and 1.5X improved productivity.
Electrical & data/Telecommunications
Residential power was provided by three (3) 4000 amp aluminum bus risers; feeding residential meter banks across 16 floors. Each unit is fed by a 125 Amp aluminum MC Feeder cable. Power to the shell and core residential floors is provided by distribution boards located on floors 7, 15, 21, 27, 36 and the roof. These distribution boards are fed with an aluminum MC cable feeder. Residential units were also furnished with additional circuitry and receptacles for stacked washer/dryer, stove, microwave hood, garbage disposal, dishwasher, and residential fan coil unit.
Residential core lighting included surface mount fixtures in electrical rooms, trash rooms, and mechanical rooms. All stairway fixtures were provided with integral occupancy sensors. LED lighting was chosen instead of recessed can lighting for lobby and retail lighting to accommodate ceiling space issues with HVAC duct. Parking spaces included LED surface garage light fixtures with integral occupancy sensors and fire alarm circuitry. A high rise life safety and emergency power system and standby system was included. McKinstry also provided all mechanical and plumbing controls, heat tracing, and fire alarm wiring.
For amenity spaces, McKinstry provided and installed CAT6 cabling, wireless access point locations, voice/data locations, coax cabling, equipment and ladder racks, and elevator phones. In each residential units, we provided and installed multimedia smartboxes preloaded with phone, data, and TV modules/splitters and data outlets, CAT5e cabling, cabling pathways and routing, cable terminations, and testing. McKinstry also coordinated the service, entrance, riser backbone cabling with the service providers.
Security scope included providing a telephone entry system tied to the CCTV camera system, access door controls, emergency stations in the garage, and public safety DAS system. While a cellular DAS system was not included in the original scope, McKinstry performed the cell DAS system review, equipment layout, benchmark testing, and final testing/documentation of the system.
For residential spaces, McKinstry provided a wet pipe light hazard system. This system included wet standpipes with hose valves inside heated stairwells at the main landings, hose valves and control valve assemblies on each main level landing, and control valve assemblies. The penthouse and back-of-house mechanical spaces have wet pipe ordinary hazard fire sprinkler systems with quick response sprinkler heads throughout the roof penthouse.
The garage included fire pump room connected to a 33K gallon water storage tank (provided by others) with an electric horizontal split-case fire pumps (primary and back-up), points of connection to the valve room. The sprinkler systems was a dry pipe ordinary hazard system with quick response sprinkler heads and valves with air compressor connected to the fire pump room. Wet standpipes with hose valves were provided at main landings in the garage. Two, flush-mount fire department connections were provided along 8th Ave and along Blanchard St.
Retail space included a wet pipe ordinary hazard shell system with provisions for future ceiling drops. Core area with suspended ceilings have quick response sprinkler heads.