20 Eastbourne Terrace is part of a group of offices located adjacent to Paddington Station and is the tallest building in a series of offices along Eastbourne Terrace. The client refurbished all of the offices to upgrade the quality of the commercial offering and attract new tenants. 20 Eastbourne Terrace was the tallest building consisting of 18 floors and had the greatest challenges in terms of vertical transportation.
The client wished to increase the population density to 1:8 without increasing the number of lift shafts. In addition, the lift shafts were not to be altered and so could not be increased in size.
From a vertical transportation perspective, this created a unique challenge in that the refurbished building would have an increased population, creating greater demand, without increasing the number of lifts. And to attract tenants, the lift performance still had to be compliant with the design criteria of The British Council of Offices
D2E through a process of innovative thinking and research, combined with the support of the major lift suppliers, developed a vertical transportation solution that allowed for larger cars within the existing lift shafts and the advent of destination control technology to allow for more efficient dispatching.
Larger lift cars were possible through studying whether thinner, longer counterweights could be used and whether different lift doors could be supplied. Allowing for larger cars meant that survey dimensions had to be very accurate as running clearances would be less, plus by changing the counterweight type, issues of balance and torque would not have an adverse impact on the lift performance.
In addition, destination control, whereby the lift user selects the destination from the landing and is allocated a lift, meant that journeys had fewer stops, had quicker journey times and typically stopped at levels in close vicinity to one another, providing a level of performance that accommodated the increased population levels.
These two key factors assisted in providing a level of performance that allowed for an increased population without increasing the number of lifts and allowed the building to have an attractive level of net internal area.