9 key considerations for designing efficient vertical transportation systems in buildings
Sweco author: Adam Scott, Technical Director Sweco UK Vertical Transportation
To achieve truly successful vertical transportation engineering outcomes, we must design seamless systems that allow people to move around their environment easily and comfortably.
In turn, there are a number of ‘consultancy cornerstones’ any partner should consider alongside your project team as a minimum. Below we look at the key things you should interrogate any potential vertical transportation on before committing to a contract.
1. Performance and Maximising Lettable Area
In major developments lift cores will occupy a significant amount of valuable space. The key tenet of an effective vertical transportation strategy should therefore always be one of minimising the lift core space take whilst meeting the agreed performance criteria. Design standards should be set and agreed at the outset of the project as they have a very significant impact on lift quantities and sizes and therefore overall building core efficiency.
For speculative commercial buildings, design standards will usually be influenced by the letting strategy and typically the British Council for Offices (BCO) Guide to Specification. CIBSE Standards are often also referenced and adopted as a base set of benchmark design criteria. However, where the occupier is known, such a “broad brush” approach to defining performance criteria mass is not appropriate and a focus on agreeing criteria specific to the observed and predicted demand patterns of the occupier is likely to result in a more efficient and appropriate vertical transportation solution. Experienced clients will often also have their own established sets of performance criteria which need to be reviewed and adopted as appropriate.
Whilst there are clear theoretical performance and space benefits in utilising destination control, its effect on the user should also be considered. Interfaces should be designed carefully to ensure requirements are clear, simple and that natural intuitive behaviour is all that is required from passengers.
Relatively recent innovations now offer passengers the option of calling a lift in a mobile phone app, which may be an attractive option to consider as the design develops particularly in a post-Covid world where touch-free interaction has never been more valued. Lift quantity and speed should be defined by dynamic simulation traffic studies that focus on average waiting times as distinct from average interval times and that take account of traffic demand to and from basement levels and leisure facilities that may exist within the building. Adopting realistic car loading factors is also an important part of this process. In tall slender buildings especially, the use of double-deck lift technology (or multi-car systems such as Twin®) should be considered as these offer greater handling capacity per lift well thereby reducing lift car space take.
2. Ride Quality
In commercial developments lifts need to deliver high levels of ride quality with low levels of noise and vibration (within economically justifiable limits). This is particularly important where machine roomless lift equipment is utilised as the machinery resides at the top of the lift well creating the potential for increased noise levels at the highest lobby. Doors need to operate smoothly and at an appropriate speed. Care should be taken where lifts serve directly onto floorplates to manage noise created by lift and door movement and in-car announcements.
3. Construction Programme
Lift installations in buildings also offer an opportunity to support and reduce overall construction programme durations and associated costs. Beneficial use of the lifts by the main contractor and their trades is an important consideration to minimise overall construction programme. This strategy sees completed lifts being placed into builders’ service to facilitate the movement of personnel and materials. Careful planning of beneficial use is important to ensure any almost inevitable damage is appropriately recorded and budgeted for, and that appropriate time is allowed in the programme to repair and recommission the lifts into an “as new” condition for final client handover. Robots have started to appear as innovations in lift guide rail installation process; the drilling and fixing of guide rail brackets becomes an automated process improving speed of installation and quality, whilst also removing the potential health and safety concern created by repetitive drilling operations by hand, i.e. white finger.
The raison d’être of most buildings is to provide a comfortable, safe, fun and productive environment within which people may live and work. Vertical transportation is the enabler for all of these things, and lies at the heart of a building experience.
Adam Scott Technical Director, Sweco UK Vertical Transportation solutions
4. Car Design
Detailed co-ordination of the interior lift car design is important. The aesthetic of the lift car finishes will support the design language of the building. Consideration should be given as to how the aspirations for the lift car design meet the code requirements for accessible lifts, (i.e. car button design, lighting levels, position of buttons, etc.) both inside the lift car and also in the lift lobbies. Consideration should be given to increasing the height of the lift doors and internal lift car height. This increase supports the high quality aesthetic however care should be taken to ensure the resulting increased headrooms can be accommodated. Where machine roomless lift technology is proposed due consideration should be given to the constraints this type of equipment can present, e.g. prescriptive scenic car design, limitation on car size and speeds, procurement restrictions.
5. Goods Service
Goods lifts should be sized to support business needs, fitout procedures and the movement of full-height partition panels, and also the movement of plant. At least one goods lift should serve roof plant if headroom constraints permit. Consideration should be given to lifts of varying sizes, ideally arranged in cores of at least two. It should be possible for all foreseen tenants to have access to at least one goods lift. It may be advantageous to “overrate” one of the goods lifts for occasional movement of very heavy plant such as transformers and / or generators.
Security of high net worth individuals is of paramount concern and should be a feature of the design throughout the development. Lifts can provide both an opportunity and a potential weakness in security strategy. Intelligent lift control systems can now interface with the user more securely to reduce the probability of unauthorised access however tailgating remains a risk that is hard to mitigate against within the lift system design.
7. Design Interface
The requirements of the vertical transportation strategy must be clearly communicated and co-ordinated with the structural design, MEP design, Fire Strategy and Accessibility Consultant. This co-ordination needs to start early and requires particular focus when these disciplines are being carried out by different consultants.
Major developments must meet the needs of its occupiers both at Day 1 and Year 15+. Needs change and the way we are building in the future will change. Vertical transportation systems need to be configured to anticipate and meet those changing needs with minimal disruption and cost to the business. Executives may need to be catered for via dedicated entrances and lift lobbies; destination control and the use of through lift cars (front & rear doors) can provide seamless, invisible segregation and security for mixed tenancies.
The lifts in a building are an integral part of the building experience for both occupiers and visitors and are therefore an important opinion former on the quality of the resident businesses. The adoption of appropriate, risk managed, innovation can enhance the quality perception of the building and its occupiers. Destination Control has now become a defacto standard for high-end commercial buildings, certainly in the UK, and the control interface and facilties can be customised to a great degree to provide VIP services, group arrival, mechanic and cleaning services, BMS integration and enhanced disabled services. Experience tells us however that these opportunities for innovation need to be adopted with careful consideration for the users’ perspective; simple clear and concise user information and interfaces provide a successful design, over-complicated systems may confuse and frustrate users.
Should the appetite exist, new products appearing on the market offer transformational design and efficiency opportunities. The MULTI lift system sees multiple cars in a lift well that are capable of moving both vertically and horizontally. This opens up not only better core – capacity configurations but potential links into the horizontal circulation routes at public realm, street level, and even underground. Such a system is at detailed running prototype stage currently but is expected to the market over the next few years.
Sweco has delivered vertical transportation consultancy services on many developments around the world, from lift consulting and escalator solutions to walkway and goods hoist engineering. We believe our approach provides clients with real added value beyond the technical challenges of engineering alone. For support on current or upcoming projects, contact us or browse our services below.