Project Description

Capital Square

Currently under construction, Capital Square is a 122,500 sqft Cat A, office development located on Morrison Street adjacent to the Edinburgh International Conference Centre. The project involves the demolition of the existing Sky Park building with the construction of a new 3 level concrete basement and 7 office levels.

Location: Edinburgh
Client: BAM Properties, Hermes Investment Management in Association with Parlison Properties
Cost: £40m
Completion: Scheduled Completion May 2020

Capital Square is located on the site of the Sky Park building, originally designed by Blyth & Blyth as part of the Edinburgh One office development. The Sky Park was demolished to make way for this new development.

The project comprises a 2 – 3 level concrete basement which provides onsite parking and provision for plant space. The basement has been constructed in close proximity to the surrounding structures. Excavations adjacent to Edinburgh One were enable through the use of large diameter Contiguous Piles.

The 122,500 sqft of office accommodation is provided over levels 00 – 07. Level 00 is a suspended concrete flat slab construction accommodating the main, double volume entrance and external landscaped gardens for the tenants. The superstructure above ground floor is steel frame construction comprising cellular steel beams with composite concrete decks.

Lateral Stability is provided by two vertical stair and lift cores located on the North and South of the building.

Key challenges

The demolition and construction of the multi-level basement is a key challenge for this project. The basement construction is located directly adjacent to Edinburgh One. This required the use of a contiguous piled wall located, constructed at the interface, to provide lateral support to the excavation of the basement and the installation of the North Core Foundations.

The excavation of the basement was achieved with king post walls on three boundaries. The King Post walls were propped at mid height by flying shores spanning the width of the basement to enable the construction of the foundations, ground slab and the first suspended slab. The temporary flying shores were removed once the suspended slab linked the North and South Cores.

The perimeter concrete walls and ground slab of the basement are constructed with a waterproofing additive, Pudlo, to limit the time required for external tanking allowing the contractor to cast the single sided walls against the temporary king post wall.

Site access is constrained on all sides and construction requires careful coordination and consideration for access and the adjacent land owners and users.


Capital Square is currently under construction and is anticipated to be complete within the program period. The construction of the visible concrete cores is complete with the completion of the Level 00 slab scheduled for end of May 2019.

Erection of structural steel is scheduled to commence at the end of April 2019.

“Edrington have worked with Blyth and Blyth for the past 15 years on various projects throughout the group and during this time we have developed a close and trusting partnership. B&B offer the full range of engineering services, allowing us to have a one stop shop on engineering consultancy requirements, with the obvious benefits this brings. B&B experience in the whisky industry is second to none which has the double benefit of not wasting time and money having to explain the process each time. As said previously, Edrington have been working with B&B for more than15 years and with a fair wind this relationship will continue for a further 15 years and beyond.”

George McKenzie Engineering Director, The Edrington Group