HomeMy WebLinkAbout06122088 ZPC Agenda Item 4
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EXCAVATIONS AND UNDERGROUND STRUCTURES
The key issues regarding excavations and underground structures are as follows:
1. A. Should the underground structure project into the yards and if so, then how much?
Should the excavation area be allowed to project into the yards? (ZPC)
al#le 17-6 ot'the Zoning ReLaiiaiiosts lists tllosc items allowed to project i11to the reguliltcd
yard". Underground .itellls are not restricted al all as to the l irtllt.s of t:hcir encroachment
into these, vary s. C'olleci_vably, a basemc11t wot.ildl technically be allowed to span the
enure hkIll i[1c'?'ite l?i'CTC11V line to plopcn€ 1111c t11)J-Cs1rIC1.CtL
B. Should underground structures be allowed on narrow lots taking the 3/7 alternate side
yard exception?
N i rro%v° lots Iles than 55` wide) are gnve11 all optioll to use ltermate side yards. This is
:11lo,,v d to erlcoura,-e rear situated tzarages. 11'a structure built undcr4zround on a narrow
site is constructed whcll takini, the alternate: side setback allowance. should there 1?e
1i111its and restrictiorls oil 111C proxilllity of rile bascrncllt wall and the excavation to
F:adljoi11i1ig property lilies.
2. If an underground structure is allowed in the yard areas, should there be special rules for
lot drainage regulations? (BSC)
Caaptcr 18 provides re;ptlation 1,01, building site drainage acid controllillo the runolf rate
bascda on 1l 1" per h.otil- rainfrlll. Slabs on grade \vill provide a ,Ynall arnot.int of per"v°ious
area 1111derneal1) the toll.ndation Cot, water absorption. It 1a fUll blasclnent. is built, will this
Impact the drainage 111 a Sldr?11111C,111t i_'IIOLigll 111,1111IC'I' tU r{;C1t111'C 11d dltloti al drail`Wge
not btpeC 111ed in Clwpior l
3. Underground structures in the 100 year floodplain are strictly controlled. Should there be
additional regulatory language controlling the basements outside the 100 year
floodplain?(BSC)
~11c1£oed portions of structltl S located in the 100 year floodpl(,.un Milc11 are below the
base flood Cie%ailora are not allowed unless they' inect criteria established in Section 11323
of the 2003 IRC, anti C'111-1pter 18 Article l of the; city's (.`ode of t)rdinzances. There are
1141 si111i1<1r I-CLa 11atio1ls for strtact111 ?t;isi i>: die Clodatll 1,11H,
4. Should there be additional engineering criteria for the foundations of underground
structures? (BSC)
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(.lklaitcc ~ 'Ic I:-, Oil dia, <tnd '3 I ilt~[T? ltl.
IM those cedes. West LJ laas araaesachaee,.as dealin'; with recltdretatents foa- different types of
t~oa.tmiatioaes. 1. asenient. ~vatlis are not Iddre° scd in this aanendmcr)t. Section 8403 of ti-ic
'003 RC addresses sol-lie aspects of bascta ei l constriction. f)rtt Cloes not address
proximity to gad acetat site's. depth of excm,atioa1.. etc,
5. Should the area included within the walls of an underground structure be counted toward
framed area? (ZPC)
l r ataaed area def iaaitiota in Article 2 of tlae Zotairay Regulatiotas lists ha-,c ineaats of a certain
I- C-
depth atad less than 8' ceilirad,~ height as an exemption to i~acla.tsi~~n ita the framed area
caalctdaat:ioaas.
6. Should the area included between the floor and ceiling of an underground structure be
counted as a story? (ZPC)
1`lae c,UITertt dekrtition of a story in the coaeing rcgtalaatiorts wvould Inclmle the hesenTaent aas
a story for compliance with the a story rttle. lf certain basements do not cotant t0Ward
Clu'lated area. then sliotdd tliey be conrtted as a story? Or if We COMA the hasernerrt area as
a story. should it be col~il~ld !(,vlatrd [lie t11ast1a"at]t1-1 allm"aahle fraantcd area;
7. What types of uses of an underground structure will be allowed? (ZPC or BSC)
.N'ny ellc l()stare located helco I)asc flood elev atiort is littaitcd to paal<in-1, atcccss to the
stmclure, acid. stor<ag, We could limit <a 1Stasti:tII0111 to these Lases only aaad not allow any
laaabitaMe azreas in tt basement.