Collins Construction
Client
January 2019 — October 2021
Duration
73–75 Grosvenor Street, Mayfair, London W1K 3JS
Location
Heritage Site
Sector
37,500 sq ft across 5 floors.
Building Size

Heritage scaffolding in the heart of Mayfair.

Three Grade II listed townhouses on one of Mayfair's most prestigious streets, originally built in the early 1700s, transformed into a single 37,500 sq ft Grade A office building without compromising a single listed feature. Collins Construction's programme at 73–75 Grosvenor Street required scaffolding that could operate with precision in one of London's most constrained and sensitive environments — through a pandemic, with noise restrictions, neighbouring properties on all sides, and a construction sequence that evolved as the buildings revealed their condition. We were awarded the Health and Safety Champion award for our work on this project in July 2019.
  • Numbers 73 and 74 Grosvenor Street were built as identical townhouses in the early 1720s. Number 75 followed shortly after as a narrower single house. The three buildings served as London accommodation for provincial nobility, later housed French silk merchants, physicians, and pioneering neurologists, and were home to figures including Clementine Hozier, who was born at number 75 in 1885 and later became the wife of Winston Churchill.

    By the time Collins Construction arrived on site in January 2019, the buildings concealed seven distinct structures of different dates behind their listed façades, interconnected poorly and in worse condition than anticipated. Opening the walls revealed listed brickwork in poor condition, requiring the construction sequence to be redesigned to create additional time for specialist conservation works. What was planned as a refurbishment became, in parts, a carefully managed structural rescue.

    The project environment added further constraint. Grosvenor Street is one of Mayfair’s busiest thoroughfares, with immediate proximity to neighbouring properties and no tolerance for disruption to the surrounding streetscape. Noise restrictions and quiet working hours applied throughout. Access for cranes and deliveries required advance coordination in a location where logistics planning cannot be improvised.

    High-risk steel frame construction and a top-down construction method were required to link the buildings structurally, with partial roof removal for crane lifts to various locations adding weather vulnerability to the programme. Covid-19 added labour uncertainty across the final phase.

  • Early engagement was central to our approach. Multiple pre-start meetings with the Collins site team established the methodology and logistics plan before work commenced, with GW Coote managing structural designs throughout — a trusted relationship across both businesses that proved critical as the programme evolved and required repeated adaptations.

    We provided full access scaffolding across the entire perimeter, with temporary roofs protecting the heritage structures and neighbouring properties during the most exposed phases of construction. Public protection gantries were installed to all elevations, with acoustic barriers to neighbouring properties managing noise impact throughout.

    Bespoke branded banners were installed to the front and rear elevations using rope access, with site-specific branding designed for the Mayfair context. Visual screening protected the façade and managed the appearance of the site on a street where presentation matters.

    A retractable curtain frame enabled safe waste removal throughout the programme. Multiple passenger hoists, goods hoists, and beam hoists managed vertical logistics across the different building levels, with cranes utilised to transport materials to locations where ground-level access was not viable.

    Where the age and fabric of the building made conventional fixing methods unsuitable, chemical resin fixings were used to tie the scaffold without compromising the listed structure. Out-of-hours working and early starts on weather-dependent operations, including the partial removal of system roofs for crane lifts, kept the programme moving while protecting the building.

  • The project completed in October 2021, delivering a unified 37,500 sq ft Grade A office building across what had been seven distinct structures. The building achieved a New London Awards 2022 Conservation shortlisting, recognising its innovative restoration, top-down construction, and the precision required to bring five floors across three separate 18th-century buildings together seamlessly.

    The interiors reflect the standard of the project throughout: a five-floor helical staircase costing over £1 million to design and install, bespoke silk interlayered glass panels in the lift core referencing the building’s history as a centre of the London silk trade, and restored 300-year-old Hanoverian staircases alongside 27 fireplaces old and new.

    The building is 100% let, with tenants including NextEnergy Capital Ltd and workspace operator Landmark. In 2025, W.RE secured a £41 million refinancing from Canada Life Asset Management, reflecting the long-term strength of what was delivered.

    Our Health and Safety Champion award for this project, July 2019, recognised the standards maintained throughout a programme of exceptional complexity in one of London’s most sensitive environments.

  • 37,500 sq ft · 3 Grade II listed buildings · 7 distinct structures unified · 5 external terraces · Full perimeter scaffolding and temporary roofs · Public protection gantries to all elevations · Acoustic barriers to neighbouring properties · Multiple passenger, goods, and beam hoists · Rope access for bespoke banner installation · Chemical resin fixings throughout · 100% let on completion · £41m refinancing secured 2025 · New London Awards 2022 Conservation shortlist · MR Health and Safety Champion Award July 2019

Services required