BRM Aug 2013 Section A - Compulsory Question

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Date

From :

JL Building Consultancy Ltd

8, Marina Square

#08-08

Singapore

To:

Esq Client

Ace Property Development Inc

Suggested Solutions

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Ace Property Development Inc

88 Central Lowlands

NN 32 RZ, Edinburgh

Scotland

Attn: Mr Walter Scott

Managing Director

RE: ADVISORY ON THE REFURBISHMENT TO TOWER CITY CENTRE

We thank you for the opportunity to provide advisory service to your company on

the recommendations and challenges in the refurbishment to Tower City Centre.

Part a)

Client’s brief / objective

The client’s objective is to update an existing old office

building built in the 50’s such that its building performance

is acceptable by modern standard and its functional use is

improved.

Background & Implications

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Currently the office building is well maintained and serviced

but experienced major vacancy at the upper floors where the

office use is. Such situation suggests that the building is

facing redundancy and possibly obsolescence. In another

words the building especially is no longer fetching market

rental value. Another hint that points towards building

obsolescence is that the building is located at city centre

and yet there seems to be less demand for the building. It is

probably also not competitive as compared to its

neighboring building.

Problem / Current Situation

The building is made of structural steel frame and its façade

is constructed using masonry panels and steel frame single

glazing.

Given that the building is now more than 60 years old we

expect the fire protection coating if there is any at all for the

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expect the fire protection coating if there is any at all for the

structural steel frame to be worn out. Its façade performance

against weather protection, water penetration should have

failed after 30 years. In another words the energy

consumption of the building in terms of heating and cooling

is likely to be very high. Its internal thermal comfort level is

likely to be unacceptable.

The building has flat roof and mastic asphalt

waterproofing. After 60 years such design would have

faced ponding issue at the roof and the warranty of

the waterproofing which usually only last for 20 years

at most has expired.

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Assuming that the owner has not replaced the roof

waterproofing, the building faces major waterproofing

issue and also water penetration at the upper most

floors. This likely impact the structural steel frame

material and causes oxidization and deterioration.

The building has a large internal floor plate. Its floor

design is open concept. In another words the building

columns are concentrated mostly at the building

perimeter and has large span beams and floor. Such

floor construction could either be metal deck flooring or

post tensioned concrete or one way reinforced concrete

slab or long span precast beam slab.

Given that the building is built more than 50 years,

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Given that the building is built more than 50 years,

modern construction technology is not available at that

time. Hence it is likely constructed using one way

reinforced concrete. Most probably there could be

spalling concrete on the ceiling arising from water

penetration from the façade or roof.

Lastly only three retail shops at operating at the building

and there is a large reception. All of these are that the

ground floor.

Options / Evaluation / Recommendation / Change of Use

I would propose the following modernization options:-

Structural steel frame – carry out repair and ensure that

new intumescent paint coat covers the structural steel

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new intumescent paint coat covers the structural steel

beam.

I recommend encasing the structural steel column with

concrete to strengthen the loading capacity of the

building and also to provide a more durable fire proofing

solution.

Façade – I recommend carrying out a re-cladding rather than

over-cladding. As the building is currently vacant at its upper

floors and only a few retail outlet at the ground floor it makes

practical sense to either terminate the retail lease or

temporarily relocate to another building if the owner has

some other building. With the relocation of the retail shops,

the building could be shut down to facilitate a faster and less

disruptive refurbishment. Given this context it is more

appropriate to carry out re-cladding rather than over-

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appropriate to carry out re-cladding rather than over-

cladding. It provides a more permanent solution in view that

the existing cladding is 60 years old already. Given that the

existing façade is masonry panel it is also not difficult to

dismantle. The new façade recommended is curtain wall with

full length double glazing that would meet the current modern

code for EETV thermal transmission. Full length glazing also

provides natural lighting which is more appealing and saves

on energy used for artificial lighting. Please see below a

sketch of re-cladding. (sketch and annotate)

Flat roof – As the building is recommended to be shut

down as justified above, we could consider re-roofing or

over-roofing of the building to provide a permanent

solution to expired waterproofing at the existing flat

rooftop and also possible water penetration issue. Re-

roofing is not recommended as the existing roof deck is

likely to have deteriorated after 60 years and may not

provide suitable gradient and water discharge. Over-

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provide suitable gradient and water discharge. Over-

roofing is more cost effective. Please see below a sketch

of over-roofing. (sketch a 3D view of over-roofing and

annotate. Indicate also the possible issues – loading on

existing column, aesthetic of roof design,

accommodating building services etc)

(You could recommend other solution eg skylight, green

roof if you have the technical knowledge)

Existing floor – The existing floor should be repaired if

there are any spalling concrete. It is also a good

opportunity to re-level the floor level if there is any

unevenness of the floor especially the circulation area or

connection area. Depending on the new use of the

building, floor penetration ie partial demolition of the floor

could be considered. This is to create a air well or atrium

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could be considered. This is to create a air well or atrium

for activity generating purpose. If an atrium is created

then skylight may need to be installed at the roof. It is an

excellent time to consider re-configuration of the internal

floor and also fit out with new wall , floor and ceiling

finishes. Internal retrofit of the building services to

upgrade the electrical capacity or air conditioning chiller

to a more energy efficient type would saves utilities cost

in future.

Change of use – As the building is a very old building,

its technical performance is unlikely to meet modern

office standards in terms of generous ceiling height,

floor loading capacity, provision for raised floor, high

electrical capacity etc.

In addition as the building is situated at city centre it

would be more viable to convert the building to a

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would be more viable to convert the building to a

hotel. More retail outlets could be considered at Level

2 as well to increase the commercial viability of the

building. With the building’s large floor plate, internal

dry partitioning could be used to create the hotel

rooms. However sanitary provisions and design

would have to be re-considered.

Construction and Access Challenges

Access – there is possible access issue as the building

is situated at city centre it is likely to be congested with

very tight site constraint with main or secondary roads

at the front and rear of the building. It is also likely that

the building is side by side with adjacent building on its

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left and right. In addition the building could be either

mid-rise or high-rise, access to the roof top to carry out

over-roofing is also another challenge.

Construction challenges – Besides access issue, as the

building is very old there are several technical risk in

carrying out work on old buildings :-

a) It is likely that there is insufficient information on the

existing building as such records could have been lost

or removed over time. Critical information are – existing

floor loading, foundation design , dimensioning of

existing structural members, presence of asbestos ,

building services performance etc.

b)The structural integrity of the building must be

maintained at all times. Hence extra temporary support

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maintained at all times. Hence extra temporary support

is required to hold the building while it undergoes

refurbishment.

c)The existing structure and design may not be able to

cater to current code compliance eg fire code,

accessibility code, energy efficiency which would

require a large plant room, carpark requirements, fire

engine access etc.

Other challenges include some issues mentioned

earlier:-

a) Strengthening of existing building loading capacity

which may require underpinning of building.

b) Relocation of existing retail tenants and

compensation if any

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compensation if any

c) Demolition and removal of debris. Storage issue

for material and equipment

d) Installation of numerous sanitary provision for

hotel guestrooms arising from the proposed change

of use from office use to hotel and retail.

e) Noise , dust and disturbance to neighbouring

buildings.