Location: Tāmaki Makaurau (Auckland)

The Pacifica

At 57 storeys high, The Pacifica reaches through Auckland’s city skyline to offer residents and tourists broad views of the harbour while surrounded by the comforts of a bustling city.

The fire safety design for The Pacifica employed an innovative response to the challenge of smoke ingress to the fire protected stairs. Each of the two stairs is internally subdivided by fire separations to limit the potential spread of smoke. This design strategy is more effective (more reliable and with higher efficacy) and less expensive to maintain than a conventional stairway pressurisation system. Each stair is provided with the ability to exit and re-enter the alternate stair to bypass any section of the stair that is compromised by smoke or blocked by firefighter activities.

The Holmes project team designed (fire modelling) and specified an innovative stairway smoke purging system which is intended to provide clear air within the stair for firefighters. Holmes provided an innovative double-curtain fire separation, to substitute for a fixed glass fire separation wall that could not be constructed due to supply issues for fire rated glazing systems.

The fire safety design considered the specific needs of the civilian occupants during a fire emergency and firefighters’ specific needs when working in a tall building (influenced strongly by the lessons learnt from the Grenfell Tower fire in London). building-specific stair signs to provide civilians and firefighters with information specific to their situation: which stairway they are in; the floor level identification (for accurate communication when assistance is needed); where the final exit is located and the number of floors to reach either the final exit or a place in the building for interim refuge or assistance). Additional WIP phones were provided to allow fire wardens to communicate with firefighters from a place of safety and for firefighters to communicate from inside the stairs to the Fire Control Room.

Fire engineering services included:

  • fire engineering design for an Alternative Solution for Code compliance
  • design and documentation of the Fire Engineering Strategy
  • coordination of fire requirements for building services interfaces
  • performance specification for the stairway smoke control systems
  • specification of the evacuation sequencing and coordination with the Evacuation Scheme consultant
  • review of and coordination with the fire protection systems consultant and contractor
  • review of passive fire stopping details at fire separation junctions, review of submissions from the specialist passive fire contractor
  • review of the fire safety systems interfaces & commissioning programme
  • construction monitoring for the duration of the construction programme
  • witnessing of fire systems interfaces operation and evacuation system sequences operation

The Hotel Britomart

The Hotel Britomart is the first eco-friendly hotel to hit Auckland, providing the city’s thriving tourism industry with a boutique offering that seamlessly blends sustainable features into an indulgent yet comforting atmosphere. Opening its doors in mid 2020, The Hotel Britomart incorporates a new 11 storey building and the refurbished, adjoining Masonic and Buckland buildings. The hotel offers 104 rooms, mixed use commercial space and administration on the ground floor, and a gym in the basement.

As the first property company in New Zealand to join the Green Star Performance rating system, Britomart successfully achieved a 5 Green Star rating during its design and build as well as its Green Star Performance accreditation since operating. This was achieved through the choosing of sustainable materials, incorporating reused concrete and recycled water through and passive design.

This project allowed our team to provide our client with a unique level of service through our collaboration with all our Holmes engineering practices including Holmes Solutions. The team from Holmes provided valuable insight into the structural elements of the design while Holmes Solutions undertook full scale testing of the precast façade panels incorporating pieces of brick.

Rigorous cooperation with the other stakeholders was required to successfully navigate the complexities of upgrading a heritage structure to current fire standards while adhering to sustainability and design requirements. The Fire Engineering strategy for The Hotel Britomart utilised smoke modelling to assess the most effective solutions for the project. Given the hotel’s height and occupancy requirements, one of the main challenges was the single stair. Through smoke modelling and egress calculations Holmes Fire showed that the stair achieves the fire safety performance requirements. The single stair was an important part of the design as it maximised the floor area available for hotel rooms.

The refurbishment of the existing Masonic and Buckland buildings included additional structural support, fire rated separations, smoke sealing and sprinkler protection.

 

 

ASB North Wharf

ASB North Wharf, headquarters of ASB bank and the anchor project in Auckland’s Wynyard Quarter, was a first-rate example of flexible working spaces and sustainable design when it was completed in 2013. The building spans two sites, with a multi-level glazed walkway over a central public lane that provides access through to the adjacent Waterfront Theatre site. 

The ‘Activity Based Working’ design presented a number of challenges that required performance based solutions. 15 individually themed, open areas were designed for flexible working also required a flexible evacuation design flexible to allow for the building’s occupants to move between floors. By utilising a performance based approach, Holmes reduced the number of stairs required by a prescriptive solution, supporting the project’s objective to create an open and flexible layout. The evacuation plan also was designed to be flexible and utilise the open interconnecting stairs for egress in some fire scenarios.  

Sustainability was also a significant factor that influenced the design and use of the building. The addition of a ventilating funnel and controlled internal shading have assisted in the reduction of the building’s energy use by 50% and resulted in the completed building achieving NZGBC 5 Star Green Star Rating for Office Design. While the ventilation funnel provided beneficial natural lighting throughout the building, Holmes designed a smoke management system that not only aligned with the ventilation system but also avoided the need for a dedicated smoke control plant. A ‘hot smoke test’ was conducted by Holmes following the completion of the project demonstrating the strategy for smoke movement in action. 

Take a virtual tour through all 7 storeys and explore ASB North Wharf.

Auckland Art Gallery Toi o Tāmaki

The Auckland Art Gallery is an iconic and much-loved part of the city’s cultural heritage. When the gallery needed to seismically strengthen and refurbish the buildings, including fire safety design—which were built in 1888 and 1916 respectively—they trusted the challenging work to Holmes’ expert engineers. The final part of the work was to design new space to host an ever-growing number of exhibits. This project required the technical expertise to cope with a challenging seismic ‘retrofit’, combined with the ability to match the character and style of the new space with the existing structure. The existing building – one of the oldest in Auckland – was the first municipal art gallery built in New Zealand and contains the most valuable public art collection in the country.

Retaining the building’s heritage features, sensitive refurbishment and upgrading fire safety was of utmost importance. Key features of the architectural design include the impressive four storey north atrium and the three storey south atrium. The new and refurbished parts of the building required large, interconnected open plan spaces with a high degree of openness and visual connection to adjacent galleries and atria.

Fire Safety Design

The fire safety design involved a challenging mix of conflicting aspirations. As the building has to deliver specific performance requirements, the fire safety engineered solution was equally performance-focused: innovative to suit this client and this architectural design. The regulators expressed concern about the number of design issues that were required to vary from ‘standard fire approaches’ and insisted on an extreme level of engineering justification. Holmes responded with engineering design solutions that addressed the significant challenges of this unique architectural masterpiece.

The fire engineering brief evolved over five years, with contributions from art curators, gallery event managers, international exhibition advisors, architects, security consultants, structural and mechanical services engineers, Fire Service and Auckland Council regulatory reviewers. The final fire safety strategy successfully achieved the outcomes required by the fire engineering brief.

Holmes used computational fluid dynamics analysis to model smoke movement and also evaluated the movement of people in a fire emergency, using a variety of engineering building use scenarios for safety and robustness. The primary public circulation routes are also used as principal fire egress routes (allowing fewer dedicated egress stairs than prescriptive regulatory requirements). Holmes coordinated a detailed review of fire protection requirements in all areas storing and displaying art. Holmes designed the systems controlling fire and smoke spread to protect the building, the art collections and the building occupants. ‘Standard’ solutions for exit signage and security on exit doors were modified to suit the specific requirements for this building.

Seismic Strengthening

The seismic strengthening work started rigorous assessment of the building’s structural needs, drawing on market-leading modelling technology to identify potential weaknesses. The strengthening solution focused on minimising the impact on existing heritage features, creating a robust, resilient structure for the future. The new space included three galleries and two new roof level sculpture terraces, and the addition of a three storey glass atrium structure with a tension rod façade system and tree-like canopies that define and cover the entry forecourt, atrium and gallery areas.

Auckland War Memorial Museum

Tāmaki Paenga Hira/Auckland War Memorial Museum is one of New Zealand’s iconic heritage buildings. It is a treasured part of Auckland’s cultural heritage, ‘telling the story of New Zealand’ to a huge number of local, national and international visitors. It’s a site of enormous cultural significance, occupying a commanding position on Auckland’s skyline.

When the structure of the museum needed to be seismically strengthened and modernised, Holmes technical design experts were the logical choice. Our design of this multi-award winning project integrated dramatic architectural and engineering features into a world class facility, bringing a national heritage building into the 21st century.

Structural Strengthening and Fire Design

The museum redevelopment was delivered in two major stages over 12 years. The first stage comprised a well-crafted refurbishment of the existing Historic Places Category I building and exhibition design for all of the gallery spaces. Significant earthquake strengthening and securing works were also undertaken, carefully integrated with existing heritage spaces to preserve the elements that make the building so distinctive and compelling.

The second stage, the Grand Atrium Project, delivered an ambitious, four storey, seven hundred tonne suspended building within the existing courtyard.  An adjacent two-level underground visitor car park was also developed, and overall floor space was increased by 60%. Two storage and curatorial basements were added beneath the stunning ground floor atrium. By utilising a wide variety of performance-based fire engineering design methods, specifically tailored to the constraints imposed by the building’s configuration and uses, Holmes optimised the performance of the egress routes within the addition, minimised the amount of applied fire proofing needed for the structural steelwork and verified the extensive use of architectural timber lining.

Finally, teaching and performance spaces situated within the suspended ‘bowl’ are crowned by the spectacular events centre, under the feature wave dome roof.

Holmes’ engineering services enabled the architect’s original vision for the project to be realised with a minimum of compromise and in a manner that significantly exceeded the client’s expectations.

Australis Nathan Building

These historic buildings, built in 1903 and 1904 were originally warehouse and storefronts for importers and merchants, fast forward over 110 years and these have been transformed to bring these heritage buildings back to life. Australis House and the Nathan Building was an ambitious refurbishment combining the two buildings to function as a single structure and repurposed them to include high end retail, hospitality and office spaces. These buildings had strong character with a combination of cast iron columns, heavy timber columns and beams, timber floors with herringbone bracing and impressive brickwork.  

Our brief on this project was to avoid providing ceilings beneath these floors and encasing these columns in order to celebrate these features. Our performance-based design solution involved a combination of sprinkler installation, assessment of inherent timber strength and application of clear intumescent coatings to achieve sufficient fire separations within the building and achieve Building Code compliance.

B:Hive Smales Farm

B:Hive is taking commercial space to a new level offering shared office space that is fresh, vibrant and architecturally impressive! This new build construction has seven levels in total. One basement level (below ground) for car parking, one on-grade ground floor level which provides hospitality tenancy spaces, meeting room and breakout spaces, entry foyer and reception for the offices above. Above this are four levels of serviced office space leased on highly flexible short term and long term basis. The top-most level is dedicated for plant and building services.  

The 11,000 square metre building incorporates a diverse mix of office uses, with a mix of dedicated and shared spaces. It has the ability to house businesses from 10 to 310 employees per floor: from small startups to established corporates. 

Two features key to the design flexibility and interactive working environment are the open atrium and stair interconnecting all office levels and the ability for tenants to use flexi-space with up to 50% more occupants than a standard office building design. Using a novel smoke control strategy developed collaboratively with the day-to-day ventilation design, Holmes justified a fire safety solution which avoided the need for fire curtains or smoke separations around the atrium.

Pier B Extension, Auckland International Airport

Auckland Airport has a number of expansion phases planned and underway on its International Terminal. The expansion of Pier B added two new gates (17 & 18), increasing the number of international aircraft using the airport. The 190-metre extension enables Pier B with the flexibility to accommodate a total of four A380 or eight smaller A320 aircraft at any time. In addition, the Pier B bus lounge was expanded from two boarding gates to four, to allow greater ability to board flights using aircraft located away from the terminal.

The project challenge for Holmes was the delivery of the construction phase in five stages, whilst maintaining the continuous operation of the airport for commuters and staff alike. Construction involved temporarily relocating the principal three main egress stairs for Pier B and then reinstating these into the permanent design. All of this needed to be undertaken without adding significant cost through temporary works.

Working with interim strategies is a frequent request of our clients, where we need to strategise closely with our project stakeholders, ensuring smooth transition of construction through to operation whilst meeting adequate safety requirements through the entire process. In doing this we take to time to understand the constraints and provide options to ensure the most workable solutions are adopted.

Using performance-based design solutions for the project provided a more efficient egress design including reduced construction costs for the client where we enabled the elimination of stairs that were part of previous fire strategies.

Feature New Zealand landscape artwork and sculpture is also incorporated to the design, welcoming guests to this area of the international terminal which has also been fitted out with a new retail store and food and beverage outlet. Feature ceilings provided challenges to our fire protection design to ensure that sprinklers were installed to operate effectively, and without compromising the aesthetics.

Middlemore Hospital MHU

Holmes is provided fire engineering services for a new mental health facility at Middlemore Hospital. The building is comprised of sleeping wards as well as activity spaces, office and administration areas. As part of the design process, extensive communication was undertaken with the hospital to meet its needs, including accommodating for phased construction that allows for the facility’s continued operational use. Our design achieves the desired open architectural layout, deviating from more restrained institutional aesthetics.

Discrete exit signage has been incorporated to reduce stimulation to the residents in the building on a day-to-day basis, while functioning effectively in the event of a fire. Additionally, reduced fire resistance ratings to sleeping rooms have been incorporated; this assisted other aspects of the building design, including security and anti-ligature requirements while limiting the number of occupants exposed to a potential fire and meeting the requirements of the NZ Building Code.

Commercial Bay | Te Toki i te Rangi

Commercial Bay is the largest mixed-use development ever undertaken in Tāmaki Makaurau (Auckland) CBD. The project combines two existing office towers with a new three level high-end retail complex and a new 39 level commercial tower—all above three levels of basement car parking and two train tunnels, with associated major complexities and structural transfers. Holmes was the Lead Structural Engineer on this important project, as well as providing fire and infrastructure engineering.

Structural Engineering 

The architecture of the flagship 39 level Commercial Bay tower in downtown Tāmaki Makaurau celebrates and showcases the structural form of the building. Working closely with the architect and the wider project team, Holmes designed visually striking columns and diagonal braces, which are clad to express and accentuate the structure. The structural system of the tower consists of a diagrid structure, featuring composite concrete filled hollow section steel tube columns and braces and long span beams.

In a large complex project with many stakeholders and challenges, the Commercial Bay tower is an example of a well-coordinated structure, underpinned by great BIM execution and a willingness for project partners to work through challenges collaboratively. This result was achieved through excellent continuous ongoing collaboration and communication between project stakeholders—particularly the architect and the structural engineers. Weekly exchanges of Revit files via a shared FTP site ensured well-coordinated Revit models and delivered a clear accurate picture of progress.

The penetrations through the floor slab were modelled in the structural slab, and penetrations for building services were incorporated into the structural steelwork floor beams. Across the project, regular meetings, ongoing communication and open, positive discussions ensured alignment and synergy through the design process.

With a premier site overlooking the harbour, Commercial Bay is already an iconic landmark on the Tāmaki Makaurau foreshore and skyline.

Fire Engineering

Holmes provided fire engineering advice for the entire development, including master-planning to allow for future subdivision of the entire block into four discrete separate properties. The fire engineering allows for separate phased evacuation and independent commissioning and ownership of fire protection systems serving the retail centre and the office tower. Holmes was also engaged to provided advice to almost all of the retail and office tenants, to integrate their specific tenancy fitout design with the overall base building fire engineering strategy.

Holmes was also engaged to provide specialist structural fire engineering services to rationalise the passive fire protection requirements of the entire tower. Advanced finite element modelling was undertaken to analyse the response of the whole floor and megaframe in fire. The analysis demonstrated the robustness of the whole structural frame in resisting a full burnout fire. The resulting analysis showed the composite columns and secondary beams did not require passive protection and a reduced FRL could be applied for the primary beams. The analysis was peer reviewed by Professor Jose Torero who is a renowned international expert in structural fire engineering.

This resulted in major savings on site with regard to project timeframes, labour and material costs, and the improved aesthetic and air quality within the space. The costs savings in fire proofing alone was estimated to be approximately NZ $4M.

City Rail Link Tunnels

The City Rail Link (CRL) runs beneath the Commercial Bay site on the Auckland CBD waterfront. Holmes, as part of a Fletcher Construction Design and Build Team, were responsible for the structural engineering design and documentation of the portion through the Commercial Bay site for the owner Precinct Properties and key stakeholder Auckland Transport. This separate CRL tunnel portion ties into the two adjacent enabling C1 contracts, C1 (Britomart Station) and C2 (Albert St).

The two box tunnels are on a curved alignment and merge into a twin tunnel box within the site. Separation of the tunnels from the surrounding development and the transfer of loads from the multi-storey office tower above were among the considerable challenges involved. The CRL box tunnels are constructed within the Commercial Bay basement area, with the structure of the development forming an enclosure over the top of them. Tension piles resist hydrostatic pressures on the base of the tunnels. The cast insitu tunnel base, walls and roof were formed using moveable formwork. The tunnels were designed for IL3 loads, with a 100-year design life.

ASB Waterfront Theatre

Located in Auckland’s popular Wynyard Quarter, ASB Waterfront Theatre is the first theatre in the Southern Hemisphere to be targeting a 5 Green Star rating for efficiency and sustainability. Offering a 650 seat theatre, it features a glass walled air bridge linking the theatre to the ASB Bank. The public artworks within the theatre have become a major attraction of the building’s design with one of the works featuring 10,000 LED lights, creating an image visible through the theatre’s glass wall.

The building was redesigned in 2012 after an initial preliminary design phase was put on hold. The new design was one of the first buildings in New Zealand to adopt the new C/VM2 Verification method for quantified performance based design. This new design approach was significant, as it allowed Holmes to develop a solution that did not require smoke detection nor a dedicated smoke extract system. This is of huge benefit to a performing arts theatre as it eliminates the risk of false activation of smoke detectors and smoke control systems as theatre effects use haze, dry ice, and artificial smoke. This solution also avoids the need to have an ‘isolate’ facility on the smoke detection and fire alarm system eliminating the need for the stage manager to monitor haze effects and other theatre-created environments which typically play havoc with smoke detection systems. Designing a fire compliant solution without a dedicated smoke extract system, activated with hatches and doors, avoided the inevitable potential compromise into what otherwise needs to be an acoustically sealed auditorium.

Key parts of the steel structure were assessed for adequate fire resistance without the need for passive fire protection, saving on construction cost.