5 Broadgate and Circle
Broadgate 5 is a new office block development built for Broadgate Estates. Mace were commissioned to do the build which would include planted roof terraces and 17 trees at ground level. The terraces on all four sides of the building are for staff working in the offices to use and enjoy the sites of London from all directions.
The Project
- Value £383K
- Duration 4 Months (phased)
- Location Liverpool Street, London
- Architects HED
- Client British Land
- Main Contractor Mace
Key Features
- Very mature 100-120cm girth tree
- Honeysuckle climber planting
- Box pleached trees
- Planters to roof terraces
- Automatic irrigation system
- Slate mulch
Key Stats
- 8tWeight of the heaviest tree
- 489m³Topsoil and subsoil
- 21Large specimen trees
- 5Years defects warranty and maintenance
- 6Different varieties of Honeysuckle used
Project Challenges
- Out of hours load out for materials to the terraces
- Large trees had to be planted at the weekend
- All works to Circle had to be done by hand using small bags of material
- Spider crane used to lower the trees into the sunken courtyard
- Road closure required for Crane to get large trees in
- Getting water from the basement upto each of the areas
5 Broadgate and Circle
Broadgate 5 is a new office block development built for Broadgate Estates. Mace were commissioned to do the build which would include planted roof terraces and 17 trees at ground level. The terraces on all four sides of the building are for staff working in the offices to use and enjoy the sites of London from all directions.
The scope of works included reservoir board, drainage layers, soils, and planting. All Materials were loaded out using a combination of external hoists, and a blue slate finish. The ground level trees were installed into a combination of special planters and prepared tree pits in the ground. The largest trees were 120cm in girth which weighed around 8 tonnes. All large trees required special transport and handling which had to occur at the weekends. Permission from the City of London was required for road closures and the pedestrian areas had to be closed off. On completion we maintained the tress for 3 years to ensure successful establishment.
Running in tandem, Mace were also commissioned to regenerate Broadgate Circle. This included us installing root barriers, drainage to the base of all the planters. All soils had to be transported from a lower basement up to the correct level by an external hoist. The small bags of soil were then manually distributed throughout. Six different varieties of Lonicera (Honeysuckle) were contract grown and planted to weave through the metal trellis. The scheme has a fully automated irrigation system which was installed by our irrigation specialist.
A spider crane lowered the large box head Tillia’s down into the open courtyard where large tree pit trenches had been formed in the concrete slab and filled with structural soils to ready to receive them.
For both parts we had to overcome a good deal of trade interface with other contractors. Many meetings had to take place to book hoists and internal lifts. Working early mornings, late nights and weekends we accomplished a high standard of work. On completion the open terraces were ready to be embraced by the new office staff and the circle is a new vibrant spaced filled with bars, cafes and restaurants.
5 Broadgate and Circle Gallery
A look at the project through our photo and video gallery
