HomeMy WebLinkAbout08072008 BSC Agenda Item 5
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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)
Fable 7-6 of tlae Zoning R.e`zulatlonas lists those lterns allov,ecl to project into the regulated
~eards. l..rnclc~r~rt>u id itcrrts are taot. restricted at a]l als to the limits of ?lreir ~ncrc~tirthrtlent
int:o tlaese vards. Conceivably. a basc,rnent would technically be alloxed to span. the
ctuire l,t.61(ling site from property line to property line tirrrestricted.
B. Should underground structures be allowed on narrow lots taking the 3/7 alternate side
yard exception?
Narrow lots (less than. 55' wide) are given an option} t:o use alternate side }-arch. This is
allowed to ncouraoe rear situated ~iara~(2es. If a structure built underLn-otind on a ;farrow
site is constructed when t:akin- the alternate side setback allowance. should there be
limits arul restrictions on the. proximity of the basement wall and the excavation to
Adjoining property lilies.
2. If an underground structure is allowed in the yard areas, should there be special rules for
lot drainage regulations? (BSC)
Chapter 18 provides re tlations for building site. (lraina4Tc ;and controlling, the runoff rage
ascd on a l" per hour rainfall. `plat), orr gra(le will provide a ,,mall amount: of per_viot.►s
area t►ncierneath. the foundation for water absorption. If a fttll basement is built, will this
intipact. the t.ln-aina e in a significalit enOL101 Inartner to requ11'e J(Aditiorral ~araina-e
11e.nst11`es ilot specrtied in. Chapter 18?
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)
1~1 rcii>,sed portions of structtnres tocati:d in the 100 year I=lootlplain which are below the
lj'e flood eie\ ation are not allowed ►_uiless they meet c;riteri i estzti)lished in Section 8323
lc ;l<tl t r IS iticlc 1Y of the city s t'o;~e c?f t3r~li►?<►ncc (here .re
o ;tt►lttr rend ►ilons for sti't.ictures outshle the (~oi;clpl:a►n.
4. Should there be additional engineering criteria for the foundations of underground
structures? (BSC)
r • •
Appendix C" OF the Wle of t:.)rcliiI'll cc, deals 1.011 thc'I'echttical Cocks and ttntendrnents
to chose codes. West U has amendments deVin; A ith requirements For different types of
iornldations. Basernent Walls are not addressed in this amendment. Section IZ403 of the
IRC atddowns some aspects of?aseme:nt Construction, bUt does 12ot :address
proximity to adjacent itcs. depth of cxcat ation, etc;.
5. Should the area included within the walls of an underground structure be counted toward
framed area? (ZPC)
I ramcd area definition in article 2 of the Zoning Regulations fists hasc illents of a certain
depth and less than 8' cedhg height as an c.vcirlption to inclusion in the framed area
catculattons.
6. Should the area included between the floor and ceiling of an underground structure be
counted as a story? (ZPC)
Ile cuuent dd inhion of a story in the coning regulativis xkvuld include the basement its
a story for compliance Nvitlt the ' :!story rule. If certain hasejnents do not count tow;zrd
(nosed area, then should they tie counted as a story:' Or if >n-e count the basement area as
a story, should it be coumed Word the maxin-11nl allowahle framed area'?
7. What types of uses of an underground structure will be allowed? (ZPC or BSC)
Any enclosure located below erase flood elevation is limited to parkin±z access to the
-trttcUUM and t{)rage. t,se could limit :i asenim io ti7ese uses only acid not allow any
h,ahitable areas in ayb;Jseri.ent. V