Snow Hill, London, EC1A

Premier Inn Ochre Ltd

Mar 2023 - Feb 2024

£3m

London, EC1A

Location & Overview

Commissioned by Premier Inn Ochre Limited (Whitbread), the project’s primary objective was the demolition and subsequent redevelopment of the site. The project site, once home to the Snow Hill Police Station, housed a historic building with a rich architectural heritage. The structure consisted of multiple levels with a mix of brick and stone construction, supported by steel columns, including a basement and sub-basement. Block A, distinguished by its Grade 2 listed status, stood as a testament to the city’s architectural legacy and was retained with minimal alterations. Meanwhile, Block B, while not listed, retained historical significance and contributed to the site’s overall character underwent extensive demolition, excluding the retention of its rear façade. The project encompassed a wide range of activities to prepare the site for redevelopment. While the primary focus was on demolition, significant enabling works were undertaken to facilitate tower crane erection and façade retention. Commencing with an extensive R&D Refurbishment survey to identify and address asbestos-containing materials, removal was conducted by John F Hunt Environmental, ensuring compliance with safety regulations. Soft strip operations involved the careful removal of fixtures and fittings, preserving heritage-listed items wherever possible while preparing the buildings for demolition. Existing building services were isolated and disconnected to facilitate subsequent demolition activities. Installation of site welfare facilities and temporary utilities ensured a conducive working environment for the site team. The demolition process, which employed a combination of manual, mechanical, and robotic techniques, targeted specific sections of Block A and the entirety of Block B. Enabling works, including piling, façade retention, and site clearance, laid the groundwork for subsequent construction phases. Temporary works, designed and implemented by John F Hunt, were instrumental in maintaining structural integrity throughout the demolition process.

Work, Challenges & Solutions

The project site presented a range of challenges including its status as a live site, close proximity to neighbouring structures, presence of listed buildings, and logistical constraints.
Additionally, conservation area regulations and heritage preservation requirements added complexity to the project. These were overcome through planning, innovative solutions, and proactive collaboration among project stakeholders tailored to the site’s unique characteristics typical of John F Hunt.
Two key innovations were pivotal in overcoming project challenges. Firstly, a bespoke protection screen was devised to facilitate the removal of a structural wall above a live car park, ensuring safety and minimal disruption to neighbouring areas. Secondly, a custom weatherproof protection system was implemented to safeguard the heritage-listed Reading Room during demolition, showcasing the project team’s commitment to preserving historical elements.
The project successfully achieved all outlined objectives in adherence to the contract scope and regulatory requirements including the strip out and demolition of Block B and the removal of Block A’s 5th-floor roof slab. Block B was demolished down to basement slab level, while Block A’s heritage features were preserved. The Heritage Listed Reading Room was preserved fully intact, with waterproofing protection measures implemented to safeguard its integrity showcasing the project’s commitment to heritage preservation. The removal of the B1 basement slab and completion of pile probing for the B2 basement extension were accomplished, laying the groundwork for future construction phases.
Circular Economy and Carbon Footprint: Despite limited opportunities for salvage due to the condition of existing fixtures and fittings, the project prioritised recycling and waste reduction initiatives, contributing to a reduced carbon footprint and promoting a circular economy achieving a remarkable 97.3% recycling rate for waste generated during construction.
Complex Temporary Works: The complexity of the project necessitated innovative temporary works solutions, particularly for retaining structures such as the Reading Room and boundary walls. Careful planning and execution were required to ensure the safety and integrity of retained elements amidst ongoing demolition activities. Customised protection screens and specialised demolition techniques were employed to mitigate risks and safeguard adjacent structures.
Tower Crane Erection: To facilitate the early erection of the tower crane, the site team had to navigate the tight spaces between existing structures, resulting in the two-storey annexe building linking Blocks A and B being demolished. Utilising specialised equipment such as the Brokk 180, the demolition was conducted efficiently, with all arisings manually removed. A reinforced concrete base was constructed for the tower crane, supported by a cruciform anchorage base.
Facade Retention System: The City of London Planning Department mandated the retention of the rear elevation wall of Block B. Initially, an external temporary steel retention system was proposed but was rejected by the City of London Highways Engineering Department. This led to the implementation of an internal retention system resulting in mini-piling works, removal of ground floor slabs, and creation of well holes at each floor level. These enabling works ensured structural integrity while complying with regulatory requirements.
Preservation of the Reading Room: Preserving the historic Reading Room within the Snow Hill police station presented a unique challenge. The room had to be retained intact while surrounding structures were demolished. This involved early demolition of non-load-bearing elements, steel bracing and support column installation, and careful isolation of existing floor slabs and beam connections.
Roof Slab Boundary Wall Removal: At the 6th-floor level of Block B, a section of the plant room wall needed removal, posing safety concerns for the neighbouring live car park. Due to licensing issues, a bespoke temporary protection screen was designed and installed allowing for the safe removal of the wall without disruption to neighbouring activities.

Achievements

The Snow Hill project exemplifies excellence in construction management, innovation, and sustainability.
Despite facing numerous challenges inherent to the site’s location and historical significance, the project team successfully delivered while preserving and respecting the site’s heritage elements.