DEMOLITION AWARDS
17
d
&
ri
NOVEMBER-DECEMBER2014
In the heart
of the city
Keltbray took the Contract of
the Year over US$1.5million
Award for thework it carried
out in the centre of London,
on one of the city’s busiest
shopping streets.
D&Ri
reports on the job in detail
T
hework that gainedKeltbray this award
coveredbuildings formerlyknownas
169 to189Regent Street,No’s 1, 2, 3&
4NewBurlingtonStreet (NBS) andNo’s 2, 3&
4NewBurlingtonPlace (NBP),witha single
basement extendedover the entire site. The10
buildings on siteweregenerally constructed
in the early1900s andwere extensivelyaltered
during the subsequent 80-100years.
Theproject required theRegent Street and
NBS façades below the cornice levels tobe
retained,whileNo’s 1and2were tobe retained
in their entiretydue to theirGrade II listing.
After takingpossessionof the site extensive
surveyswereundertaken tounderstand the
existenceof services, asbestos, andother
hazardousmaterials.
During thedesignof the façade retention
scheme, extensivemeetingswereheldwith the
WestminsterCityCouncil (WCC)highways
team togainagreement to excavate the
surroundingpavements. The excavations, once
complete,would establish thepositionof all
buried services and in turn allow the in-house
temporaryworksdesign engineers toposition
the foundations of the façade support towers.
Inaddition to the locationof theburied
services thedesigners alsohad to contend
with thepositionof thenearbyLondon
Underground system, theBakerloo line tunnels
passunderneathRegent Street approximately
8m (26.3 ft) from the façade,with the crown
level of the tunnel approximately21m ((69 ft)
belowpavement level.
The excavationshad tobedone in
accordancewith theWCCguidelines but also
be sympathetic to thenormal functioningof a
verybusy citypavement and tourist area.
FACADE RETENTION
The client’s engineer façade retentiondesign
intent asked for two support towers along the
Regent Street elevationand theNBS elevation.
Due to the extensivequantityof services
within thepavement,Keltbrayand its in-house
temporaryworks engineerwere able tovalue
engineer this system toone support tower
along theRegent Street elevationby relyingon
the adjoining structure
Meanwhileworkshadbegun to form the
access/egress entrance to service theproject,
alongwith the earlyasbestos removal and
soft strip to thebasement areas and the inner
courtyardarea.During thekeyphases, the
sitehaddayandnight shifts inoperation
undertaking façade retention, Portland stone
dismantling, high level structural demolition,
erectionanddismantlingof demolition
scaffolding, erectionofMason scaffold,
installationofwelfare accommodationon
the façade retention steel frame, basement
enablingworks and soft strip, all throughone
entrance.
High level cantilevered scaffoldwas
installed to enablehigh level demolitionworks,
stonedismantlingand leadwork salvage
earlyon in theprogrammewhile the façade
retentionpilingand existing foundation
removalworksprogressedat basement and
ground level concurrently.
The site –Regent Street
runs from lower left to
mid rightwith themain
complex aboveRegent
Regent Street in the centre
of the picture (right)
Muck away lorries had to reverse into site
