images:
nigel rigden
(right); simon maxwell (left)
homebuilding.co.uk 137BuNgaloWs reimagiNed
above:Thisrun-down
bungalowwasbuiltin 1998
andis satona heavily
slopingsite.architect
anniemartincameupwith
a designthathasbrought
inlotsofnaturallightand
makesthemostofthe
challengingplot.(www.
anniemartin.co.uk);
left:opening up spaces
and using roof lanterns
is the ideal way to bring
natural light into dark,
central spaces.lFoundations
Hopefullyyouhaveaccesstotheproperty
deeds,alongwithoriginalconstruction
drawings.Theseshouldshowthedepth
andtypeoffoundations,thedrainage
systemandwhichinternalwallswerebuilt
withfoundations.If not,trackdownlocal
buildingcontrolrecordsif youcan.
Otherwise,yourbestoptionis to
consulta structuralengineer.Theywillbe
abletoadviseyouongroundconditions
andwillbelikelytosuggestdiggingtrial
holesinordertomeasurethedepthand
assesstheexistingfoundations.
“Foundationsmustbecheckedbya
structuralengineerasearlyaspossible
toestablishthefeasibilityoftheproject,”
explainsarchitecturaltechnologistTony
Holt.“Thisincludescheckingexternal
wallsandinternalwallsasbotharelikely
toberequiredtotakenewloadings.We
havecomeacrossmasonryinternalwalls
thathave been built straight off oversite
concrete (a layer of concrete laid onto the
ground below suspended timber floors).
Just because a wall is in masonry, doesn’tguarantee it’s been built off a foundation.”
Once the results are received your
structural engineer will be able give you
information on whether the existing
foundations are strong enough to
supportanadditionalstorey.If not,the
foundationswillneedtobestrengthened
orunderpinned—although it may only be
necessary to strengthen certain areas.l Masonry or timber frame first floor?
While both masonry and timber frame
are options when it comes to adding an
additional storey, timber frame is often
chosen as the weight is less than that of
masonry. This may, in some cases, remove
the need for underpinning foundations.
“We have utilised both off-site
prefabricated timber frame solutions and
on-site fabricated timber frame — both
are viable solutions,” says Tony Holt. “We
have also built up in masonry, which is an
option for certain design solutions.
“The choice of timber frame or masonry/
steel is usually a big consideration in the
early stages of the design process. I tend toBeFore