Early specialist support crucial for tall buildings – Modern Building Services (weblog)

Revealed:  05 July, 2017

The early involvement of specialist contractors will be increasingly important to the successful design, delivery and operation of tall buildings, says BESA technical director Tim Rook. The direction of construction in this country is up. We are building faster, denser and higher — yet most tall buildings are approached as ‘bespoke’ projects with no standard approach to their design, construction and operation. With over 200 new high-rise buildings planned for London alone, it is clear that a unified set of guidelines for the supply chain is urgently needed.  Most high rise structures are mixed use — residential; retail; commercial office; leisure etc. — all of which can change radically during the building’s operating life. The design process can also last for many years and is, therefore, at the mercy of significant economic, political and social changes that can radically alter the developer’s vision for the building part way through construction.  All of this creates a unique set of challenges for the technical trades given the task of designing, installing, commissioning and operating the services.  Today’s tall buildings are more like vertical cities with a wide variety of occupants and rapid changes of use. The design team also has to be thinking extremely long-term — 80, 90, 100 years. What services will future generations of occupants need, and how will technology alter how they are delivered? Will they need a car park for all-electric, driverless cars? Will there be cars at all?  Handover Even post-occupancy warranty issues need to be considered early because these can be extremely complex to satisfy multiple tenants, all with different requirements. The project team has to be aware of the type of warranties that will be given at the end — even if the handover process is many years in the future. At the Building Engineering Services Association (BESA), we have been working on these questions for some time. We have launched an interactive ‘wiki’ to gather expert data and recently hosted a supply-chain forum comprising architects, consultants, contractors, builders and legal specialists all with particular expertise in tall buildings. In a full-day interactive session, the BESA forum looked at how tall-building supply chains currently operate and where this is creating weaknesses in delivery and long-term operation. The members considered the implications for the surrounding area and the local community and how a tall building becomes a catalyst for other projects and other spaces. The definition of ‘tall’ covers any building where, because of its height, there are specific engineering challenges, changes and additional considerations that go beyond normal practice in order to ensure a safe and efficient system.  Therefore, the forum members looked at how the specific challenges created by tall structures impacted on the design and safety of pressure systems, pipework and jointing selection, anchoring and expansion, fire systems (sprinklers, dry risers), large VRF air-conditioning systems, cold water services and many more.  Over 20% of the total construction costs are down to M&E services, according to the consultants Davis Langdon. Yet specialist contractors with crucial knowledge of these services are usually left out of the process until the later stages — a fact that the whole forum agreed was hampering project delivery and undermining ongoing operation of the completed building. With multiple types of occupant, the arrangement of the services is a ‘day-one issue’, with an early decision made about the position and nature of the services ‘core’ critical to the overall design. Similarly, construction logistics need to be considered from the outset as most tall buildings are in tight urban areas — creating serious access issues, particularly with the amount and size of equipment to be transported in. It was recognised by the forum that a great deal of value can be brought to the table by the contractors who will carry out the work and that it would be preferable to do this early in the design process. There was even a willingness to consider making this a paid-for service.  Some developers do bring in specialist contractors at design stages 2 and 3, which can be as much as five years before work starts on site in a complex tall building. However, in most cases the specialists are brought in after construction has begun — and that is too late.  Concept Architect Simon Bowden told the BESA forum that lifetime design should be a priority right from the concept design — with the architect, client and developer being clear about how long they expected the building to operate. He said, ‘You must make the building flexible enough to deal with changes in use — particularly in the office space. You need to look at the floor plate; it is wrong that so many offices are demolished when they should have been designed for re-use with a longer design life built in.’ WSP Parsons Brinkerhoff technical director Peter Brickell said ‘everything depends on the core’. “If you are building for residential then you need the core in the centre to maximise living space around the perimeter, but offices often have different requirements, with a deep floor space and only senior management out on the edge of the floorplan,’ said Mr Brickell. He said that a floor plate of approximately 18 m was a good rule of thumb because it works for residential, hotels and offices — and can be adapted later depending whether the core is in the centre or not. He added that the design team should look to ‘blur the lines between office and residential so you can change in future, aiming for spaces that could suit both, with floor-to-floor heights of around 4 m. ‘If the cores are at the edge, you can keep the integrity of the floor plate when making changes.’ However, this means that heating and cooling loads must be discussed at the outset because every occupant will have their own particular needs and targets, which have a ‘profound impact on the design of the core and, by implication, the footprint’, according to Valeria Khnykina of SSE. ‘One of the first decisions should be the position and size of plant — basement/mid-level/rooftop,’ she added. ‘If you have chiller plant on the roof, that has major structural implications. And if you have a hotel in there, will it want its own services arrangement because of its different usage patterns to the offices etc.?’ If the building is to be connected to a district-heating supply that also has to be designed early so you need to know what the loads will be — particularly if you want an efficient ∆T (hot water supplied at 90 to 105°C, with the return at 30 to 40°C). So, will there be a requirement for buffer vessels or thermal stores? The forum also discussed the role of lower-temperature systems as a result of increasing use of heat pumps and the difficulty that could create in getting the right balance of temperatures across the whole structure.  Awkward Early input from the FM team is essential to ensure good management of the technology throughout the building’s operating life. BESA vice president Giuseppe Borgese said that core services should be done in such a way ‘so that you don’t need to shut down the whole building when replacing or refurbishing’, but that often requires FM specialists to make themselves unpopular by asking awkward questions of the designers. From a construction point of view, ‘Verticality is really important,’ said Kevin Mason of Briggs. ‘In lots of projects, the services are removed from the core and that creates real problems. If you have toilets at every level, then you have waste pipes coming through in various places and that can have a big impact on your flexibility.’ He said manufacturers were producing more modular equipment and offsite fabrication was improving. ‘However, they could put more thought into how it is ultimately going to be assembled on site. For example, do the pieces of plant have to be so big? Or can you give us boxes that can be taken apart and reassembled on site to ease access and lifting issues?’ He also stressed the importance of managing operating pressures in tall buildings and techniques for avoiding the need for interstitial plant rooms as these add cost and complexity while also taking up valuable space. Advances in mobile technology mean the integration of smart systems and how they are going to control the services is another early consideration, according to Tom Smith, global director at WSP Parsons Brinkerhoff. He said this also had long-term implications for the health and well-being of occupants. This is an increasingly important consideration for clients that goes beyond obvious issues like indoor air quality to how people are being encouraged to use the stairs more often than the lift, for example, as part of the WELL Building Standard, which is now being adopted in many countries. The BESA tall-buildings forum is continuing its work to develop industry standard guidance, which will be developed and published on a sub-topic by sub-topic basis via its ‘wiki’. Adopting this dynamic, online approach will enable the working group to readily update its content with strong links between sub-topic publications and make access easier for members.  For further information or to join the wiki task please email: mark.oakes@theBESA.com.  a floor plate of approximately 18 m was a good rule of thumb because it works for residential, hotels and offices — and can be adapted later depending whether the core is in the centre or not

Summarising considering on tall buildings — Tim Rook.

The early involvement of specialist contractors can be more and more vital to the profitable design, supply and operation of tall buildings, says BESA technical director Tim Rook.

The path of building on this nation is up. We're constructing quicker, denser and better — but most tall buildings are approached as ‘bespoke’ initiatives with no commonplace strategy to their design, building and operation. With over 200 new excessive-rise buildings deliberate for London alone, it's clear unified set of pointers for the provision chain is urgently wanted.

Most excessive rise buildings are blended use — residential; retail; business workplace; leisure and so forth. — all of which may change radically through the constructing’s working life. The design course of can even final for a few years and is, due to this fact, on the mercy of great financial, political and social modifications that may radically alter the developer’s imaginative and prescient for the constructing half means via building.

All of this creates a novel set of challenges for the technical trades given the duty of designing, putting in, commissioning and working the companies.

In the present day’s tall buildings are extra like vertical cities with all kinds of occupants and fast modifications of use. The design workforce additionally needs to be considering extraordinarily lengthy-time period — 80, 90, 100 years. What companies will future generations of occupants want, and the way will know-how alter how they're delivered? Will they want a carpark for all-electrical, driverless vehicles? Will there be vehicles in any respect?

Handover

Even submit-occupancy guarantee points should be thought of early as a result of these will be extraordinarily complicated to fulfill a number of tenants, all with completely different necessities. The challenge workforce has to concentrate on the kind of warranties that can be given on the finish — even when the handover course of is a few years sooner or later.

On the Building Engineering Services Affiliation (BESA), we now have been engaged on these questions for a while. Now we have launched an interactive ‘wiki’ to collect professional knowledge and lately hosted a provide-chain discussion board comprising architects, consultants, contractors, builders and authorized specialists all with explicit experience in tall buildings.

In a full-day interactive session, the BESA discussion board checked out how tall-building provide chains at present function and the place that is creating weaknesses in supply and lengthy-time period operation. The members thought of the implications for the encompassing space and the area people and the way a tall constructing turns into a catalyst for different initiatives and different areas.

The definition of ‘tall’ covers any constructing the place, due to its top, there are particular engineering challenges, modifications and extra issues that transcend regular apply in an effort to guarantee a protected and environment friendly system.

Subsequently, the discussion board members checked out how the precise challenges created by tall buildings impacted on the design and security of stress programs, pipework and jointing choice, anchoring and growth, fireplace programs (sprinklers, dry risers), massive VRF air-conditioning programs, chilly water companies and plenty of extra.

Over 20% of the entire building prices are all the way down to M&E companies, in response to the consultants Davis Langdon. But specialist contractors with crucial information of those companies are normally overlooked of the method till the later phases — a incontrovertible fact that the entire discussion board agreed was hampering challenge supply and undermining ongoing operation of the finished constructing.

With a number of forms of occupant, the association of the companies is a ‘day-one problem’, with an early determination made in regards to the place and nature of the companies ‘core’ vital to the general design. Equally, building logistics should be thought of from the outset as most tall buildings are in tight city areas — creating severe entry points, significantly with the quantity and dimension of kit to be transported in.

It was recognised by the discussion board that a substantial amount of worth will be dropped at the desk by the contractors who will perform the work and that it could be preferable to do that early within the design course of. There was even a willingness to contemplate making this a paid-for service.

Some builders do herald specialist contractors at design phases 2 and three, which will be as a lot as 5 years earlier than work begins on web site in a posh tall constructing. Nonetheless, typically the specialists are introduced in after building has begun — and that's too late.

Idea

Architect Simon Bowden informed the BESA discussion board that lifetime design must be a precedence proper from the idea design — with the architect, shopper and developer being clear about how lengthy they anticipated the constructing to function.

He mentioned, ‘You will need to make the constructing versatile sufficient to take care of modifications in use — significantly within the workplace house. You might want to take a look at the ground plate; it's incorrect that so many places of work are demolished when they need to have been designed for re-use with an extended design life in-built.’

WSP Parsons Brinkerhoff technical director Peter Brickell mentioned ‘the whole lot is dependent upon the core’.

“If you're constructing for residential then you definitely want the core within the centre to maximise residing house across the perimeter, however places of work typically have completely different necessities, with a deep ground house and solely senior administration out on the sting of the floorplan,’ mentioned Mr Brickell.

iStock.com/alphaspirit

He mentioned ground plate of roughly 18 m was a great rule of thumb as a result of it really works for residential, inns and places of work — and will be tailored later relying whether or not the core is within the centre or not. He added that the design workforce ought to look to ‘blur the traces between workplace and residential so you'll be able to change in future, aiming for areas that would go well with each, with ground-to-ground heights of round four m.

‘If the cores are on the edge, you'll be able to hold the integrity of the ground plate when making modifications.’

Nonetheless, because of this heating and cooling hundreds have to be mentioned on the outset as a result of each occupant can have their very own explicit wants and targets, which have a ‘profound influence on the design of the core and, by implication, the footprint’, in response to Valeria Khnykina of SSE.

‘One of many first choices must be the place and dimension of plant — basement/mid-degree/rooftop,’ she added. ‘When you have chiller plant on the roof, that has main structural implications. And in case you have a lodge in there, will it need its personal companies association due to its completely different utilization patterns to the places of work and so forth.?’

If the constructing is to be linked to a district-heating provide that additionally needs to be designed early so it's worthwhile to know what the hundreds can be — significantly if you'd like an environment friendly ∆T (sizzling water provided at 90 to 105°C, with the return at 30 to 40°C). So, will there be a requirement for buffer vessels or thermal shops?

The discussion board additionally mentioned the function of decrease-temperature programs because of rising use of warmth pumps and the issue that would create in getting the fitting stability of temperatures throughout the entire construction.

Awkward

Early enter from the FM workforce is important to make sure good administration of the know-how all through the constructing’s working life. BESA vp Giuseppe Borgese mentioned that core companies must be achieved in such a means ‘so that you simply don’t must shut down the entire constructing when changing or refurbishing’, however that always requires FM specialists to make themselves unpopular by asking awkward questions of the designers.

From a building perspective, ‘Verticality is basically vital,’ mentioned Kevin Mason of Briggs. ‘In a lot of initiatives, the companies are faraway from the core and that creates actual issues. When you have bogs at each degree, then you could have waste pipes coming via in varied locations and that may have a big effect in your flexibility.’

He mentioned producers have been producing extra modular tools and offsite fabrication was enhancing. ‘Nonetheless, they might put extra thought into how it's finally going to be assembled on web site. For instance, do the items of plant must be so massive? Or are you able to give us containers that may be taken aside and reassembled on web site to ease entry and lifting points?’

He additionally harassed the significance of managing working pressures in tall buildings and strategies for avoiding the necessity for interstitial plant rooms as these add price and complexity whereas additionally taking on useful house.

Advances in cellular know-how imply the mixing of good programs and the way they will management the companies is one other early consideration, in response to Tom Smith, world director at WSP Parsons Brinkerhoff. He mentioned this additionally had lengthy-time period implications for the well being and nicely-being of occupants.

That is an more and more vital consideration for shoppers that goes past apparent points like indoor air high quality to how persons are being inspired to make use of the steps extra typically than the carry, for instance, as a part of the WELL Building Normal, which is now being adopted in lots of international locations.

The BESA tall-buildings discussion board is constant its work to develop business commonplace steering, which can be developed and revealed on a sub-matter by sub-matter foundation by way of its ‘wiki’. Adopting this dynamic, on-line strategy will allow the working group to readily replace its content material with sturdy hyperlinks between sub-matter publications and make entry simpler for members.

For additional info or to affix the wiki process please e-mail: mark.oakes@theBESA.com.

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