Hurley Palmer Flatt

1. Designing For Flexible Spaces
Implications of shorter leases.
Adrian Gray, Hurley Palmer Flatt Executive Director, comments on the issue of shorter office
leases and how they have directly affected designing for flexible spaces.
Traditionally commercial offices in the UK, and particularly in London, have been designed to
be let on a 25 year basis. Long leases have long been considered attractive by landlords as it
allows the asset to yield a consistent return over a fixed term, which makes the building easy
to value and trade. Incentives, such as initial rent free periods have been used to encourage
tenants to sign up long-term.
However, the 25 year lease is peculiar to the UK. Elsewhere in the world, offices are often let
on much shorter terms, typically closer to ten years in the USA and Australia and even
shorter in Singapore and the Far East.
In recent years, London has become even more international and many occupiers are now
questioning the wisdom of committing to long leases. This has generated some downward
pressure on the market reducing the average length of office leases.
Recent surveys by CBRE and the British Property Federation have shown that since 2012, the
average lease length has been shortening. Leases over ten years are now a rare event and
make up only six percent of new leases.
The distribution of lease lengths shows how rare leases over ten years have become in recent
years.
Less than six percent of leases are over ten years in length now, compared to twice that only
five years ago and more than 20 percent ten years ago.
Managed and serviced offices.
Both managed offices and serviced offices are flexible officespace solutions that can be
convenient for companies who do not want or cannot commit to long-term leases. Serviced
offices differ from managed offices in two main aspects. First of all, serviced offices have
been built to specification, keeping the needs of modern businesses in mind. Secondly,
rental fees for serviced offices are fully inclusive. On the other hand, managed offices often
consist of vacant space rented out by the company or by the individual that owns the space.
Since the space will not have been necessarily built to be occupied as an office, tenants may
have to invest in things like office furniture and telecommunications. Most managed offices
are fitted with basic amenities like workstation partitions and cabling, and their fees may
include office cleaning, but they do not offer clerical support, dedicated meeting rooms,
reception services, and the full range of facilities offeredby serviced offices.
How does this affect how a building is designed?
Shorter leases mean that buildings will be fitted-out more often, whilst staggered leases with
multiple tenants can mean that there are often some tenants fit-out work being undertaken
somewhere in a building.

2. To take account of this, office buildings now have to be more flexible and many developers
are now taking this into consideration when setting a brief for the design team.
In terms of general arrangement, to facilitatemore frequent fit-out work, there should also
be adequate access to the goods lift at ground floor level with a separate route that avoids
the reception. The goods lift should also be adequately sized to allow the transportation of
fit-out materials.
This also affects our work as building services engineers as there are many aspects of a
buildings flexibility that depend on the correct approach to the design of services. This
generally means that services should be adaptable and easily modified to suit different room
layouts in the least amount of time and with as little disruption as possible.
Risers and plant rooms.
Careful consideration needs to be given to commissioning and how this can be achieved
with minimum disruption in an occupied building.
This can be as simple as ensuring that equipment and valves are easily accessible but can be
taken further by specifying addressable controllers and electronic measuring devices. This
allows the flow of air and water to be adjusted remotely with little or no disruption – other
than the periodic calibration of equipment.
Mechanical air services.
Fresh air systems should be designed to be flexible and this can be achieved by including
variable volume boxes to control the flow of fresh air to floors and even parts of floors. Even
more control could be afforded by introducing VAV boxes to control the flow to zones or
batches of fan coil units. These control devices can be individually addressableand linked to
the BMS to enable adjustment without the disruption of accessing tenant’s space.
The central air system should also be capable of providing a variable volume of air by using a
variable speed drive that is controlled by a pressure sensor in the fresh air riser.
On the secondary side of the ductwork system, flexibility can be introduced by using multi-
fan fan coil units, where the individual fans within the unit each provide air to just one grille.
This provides the ability to vary the amount of air to each grille by adjusting fan speeds
individually to suit requirements. It is possible to do this remotely using the BMS – Individual
fans can also be turned off if necessary.
With careful design it is possible to allow for multiple configurations of offices and meeting
rooms within the same space and to make adaptations without disturbing the ceiling grid.
Mechanical water systems.
The main cooling system should be designed and selected to operate efficiently at lower
loads as in a flexible spacebuilding, the requirements will be subject to constant change and
part load operation will be more of a frequent occurrence.

3. Primary circulation pumps should be capable of providing variable flow so that the flow can
be adjusted to meet the demands of secondary systems.
Tenants’ secondary water circuits should be separated from landlords systems by a heat
exchanger. This will allow draining, flushing and cleaning of the tenant’s water systems to
take place without the disruption of the landlord’s primary circuits.
Mechanical services above a false ceiling have to be modifiedto accommodate changes to
partition layouts; the most disruptive part of this work is the cutting of pipe work which
requires isolating and draining.
Where offices are designed to be very flexible, it is advisable to fit additional connection
points so that further fan coil units can be added quickly and without too much disruption.
Other important factors are metering and the ability to control systems on a floor by floor
basis with the possibility of further sub-division.
Tenants place space.
The provision of external space for tenants to use and locate plant and equipment also
becomes more important.
It is important to carefully consider the potential usage of the building during the design
stage; this should form part of the concept and strategic briefing exercise.
Most occupiers will require resilient cooling for computer rooms.
Electrical systems.
Whenever a tenancy change occurs the building design needs to allow flexibility for a
change in layout and this will occur more often with shorter tenancies. As with the
mechanical systems it is important to consider how equipment can be adjusted and
commissioned whilst keeping disruption to a minimum.
The use of intelligent lighting control systems and fittings, including dimming control, allows
flexibility for a change of layout. The use of addressable dimming adds even more flexibility
and control.
Fire alarm systems and smoke detectors should be designed to allow the maximum amount
of flexibility with sufficient spare capacity to allow for the incorporation of additional
meeting rooms or cellular offices.
Frequent changes of use on floors may lead to a variation in the small power requirements.
An efficient way to provide flexibility for this is to incorporate additional capacity in the
electrical risers to allow for varying amounts to be taken at each floor during the lifetime of
the building.
Electrical and water services metering should be installed on a floor by floor basis to allow
for future split tenancy’s.