Loading...
HomeMy WebLinkAbout07102008 ZPC Agenda Item 4 Sallye Clark From: Debbie Scarcella Sent: Wednesday, June 11, 2008 11:04 AM To: Sallye Clark Subject: FW: ZPC Meeting of June 13, 2008 Attachments: Underground structures.doc Could you forward these to the :_hen let"s ijar-j t IGG 0S or €.o norrcw night? Thank you. From: Richard Yehle [mailto:reyehle@comcast.net] Sent: Tuesday, June 10, 2008 8:01 PM To: Debbie Scarcella Cc: Sallye Clark Subject: ZPC Meeting of June 13, 2008 Debbie, I will not be able to attend the ZPC meeting on Thursday due to attending my daughter's graduation in Boston. Nevertheless, I wish to offer comments on Items #3 and #4 of the agenda. 3. Variances and special exceptions i am still struggling with item #6 of the Special Exception language. Making it a requirement that the violation must eventually be cured (even at reasonable cost and at some future time) in order to get the Special Exception seems to go against the purpose of the Ordinance. I point to the Vanesko steel-frame roof as an example of something that could never be realistically fixed, yet by all reports (I have heard) was not an issue to anyone in the neighborhoods. So long as the other provisions of the ordinance are properly evaluated and there is no significant impact on another person (#5), it seems that #6 could offer two solutions. The first would be the requirement proposed to remedy the violation at "modest or reasonable" cost whenever possible. Perhaps the reasonableness of the cost dimension could be defined in either absolute dollars or expressed as a percentage of the fair market value of the structure at the time the Special Exception is granted. The second would allow the violation to exist on a grandfathered basis under the theory that it is doing no harm and is too expensive to fix. Once either course is determined, it could not be altered except by another ZBA Special Exception, which presumably would be very difficult to achieve. 4. Excavations and Underground Structures I have annotated the Staff analysis included with the Agenda. My comments are obviously without the benefit of discussion and therefore should not be taken as final. However, I am reasonably resolved that underground space should not be considered as Framed Area and probably should not count toward the 2 1/2 story rule. Please see the attached document. Regards, Dick Yehle ZPC Commissioner i 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) Table 7-6 of the Zoning Regulations lists those items allowed to project into the regulated yards. Underground items are not restricted at all as to the limits of their encroachment into these yards. Conceivably, a basement would technically be allowed to span the entire building site from property line to property line unrestricted. For the sake of protecting neighboring properties from damages arising from subterranean encroachment "standard" sideyard and rearyard setbacks should apply. An exception might be made for frontyard setbacks, perhaps allowing development to the street setback line or perhaps only to the allowed front porch projection. Excavation should be managed on a case by case basis considering existing structures, driveways and trees, but in no case be closer than 3 feet to the property line. While that limitation might impede some underground construction, it would avoid issues such as already exist with neighboring properties being encroached by some construction jobs such as brick laying. B. Should underground structures be allowed on narrow lots taking the 3/7 alternate side yard exception? Marrow lots (less than 55' wide) are given an option to use alternate side yards. This is allowed to encourage rear situated garages. If a stricture built underground on a narrow site is constructed when taking the alternate side setback allowance, should there be limits and restrictions on the proximity of the basement wall and the excavation to adjoining property lines. As suggested in A. above. for the purposes of protecting adjoining properties, underground structures would not be eligible for the 317 alternate sideyard exception but could be built with the standard 5 foot (or 1090) setback. The 3/7 rule could still apply to the above ground parts of the structure. 2. If an underground structure is allowed in the yard areas, should there be special rules for lot drainage regulations? (BSC) Chapter 18 provides regulations for building site drainage and controlling the runoff rate based on a 1" per hour rainfall. Slabs on grade will provide a small amount of pervious area underneath the foundation for water absorption. If a full basement is built, will this Note: Comments in Italics are those of Dick Yehle prepared 6/10/08 1 impact the drainage in a significant enough manner to require additional drainage measures not specified in Chapter 18? The incidental water storage under a slab is too small to be a factor and should be ignored. Evidence suggests that too much credence is given to the water absorption capabilities of West U soil. Once the soil is saturated, which is said to happen quickly, unpaved areas don't retain much more water than paved areas. The site drainage rules should continue to be enforced, especially for any sump pump drainage originating from the underground structure. 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) Enclosed portions of structures located in the 100 year floodplain which are below the base flood elevation are not allowed unless they meet criteria established in Section R323 of the 2003 IRC and Chapter 18 Article IX of the city's Code of Ordinances. There are no similar regulations for structures outside the Floodplain. Appropriate floodplain rules should apply. 4. Should there be additional engineering criteria for the foundations of underground structures? (BSC) Appendix C of the Code of Ordinances deals with the Technical Codes and amendments to those codes. West U has amendments dealing with requirements for different types of foundations. Basement walls are not addressed in this amendment. Section R403 of the 2003 IRC addresses some aspects of basement construction, but does not address proximity to adjacent sites, depth of excavation, etc. Standards for basement walls and floors should be developed, to include any issues with subterranean drainage. There could be issues of sump pump discharge into the sanitary sewers to consider. 5. Should the area included within the walls of an underground structure be counted toward framed area? (ZPC) Framed area definition in Article 2 of the Zoning Regulations lists basements of a certain depth and less than 8' ceiling height as an exemption to inclusion in the framed area calculations. The concept of framed Area is concerned with managing the appearance of bulk in a structure not its overall size. Therefore (the subterranean part of) basements should not count toward Framed Area. Note: Comments in Italics are those of Dick Yehle prepared 6110/08 6. Should the area included between the floor and ceiling of an underground structure be counted as a story? (ZPC) The current definition of a story in the zoning regulations would include the basement as a story for compliance with the 2 1/2 story rule. If certain basements do not count toward framed area, then should they be counted as a story? Or if we count the basement area as a story, should it be counted toward the maximum allowable framed area'? As with the Framed Area rule, the 2 '12 story rule is in part primarily intended to manage the appearance of size in structures. Space below grade does not add to size and should therefore not a be a factor. (See #7 for further comments.) 7. What types of uses of an underground structure will be allowed? (ZPC or BSQ Any enclosure located below base flood elevation is limited to parking access to the structure, and storage. We could limit a basement to these uses only and not allow any habitable areas in a basement. An additional consideration of the 2 ',z story rule is the safety of living areas on the "third" floor, especially egress. To the extent habitable areas are allowed in basements, minimum standards for stairwells and windows should apply. An additional concern might be with parking in basements. Having vehicles under the house with limited means for emergency crews to access the space (i.e. realistically only the driveway), could be an issue. Also the standards for driveway access to a basement garage may need special consideration about the angle of descent and possibly uncontrolled storm drainage. Note: Comments in Italics are those of Dick Yehle prepared 6/10/08 3 EXCAVATIONS AND UNDERGROUND STRUCTURES By Debbie Scarcella, city Planner-, June 9, 2008 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) F-Pie 7-0 of the zoliin,2 Rog(llant_)IIS ;Nt~, "11w C itcru~, to protect HIIo the regulated ards. L Tldcl--lrourld ;tclns are llot restricted at 111 <.ls to the 11111it_s oJ'then- cI1CW;IClhnlerlt into t.llcse "ards. Colhce.ivably, a bz1"enleilt would teclllhically l-)e alioeeed to spars the llilic to nl'O7P.,11. i'ilc i11"F.,1"~trict'id. B. Should underground structures be allowed on narrow lots taking the 3/7 alternate side yard exception'? ~1a1'l"Cae[r?ta 1v,~~ til r~ cl .;1c ~1 cll a iii , ~~3 t 1; i , :1 1,} i1 rx)t ti ,o ,.itiC „liLrE C' :tl;, L, rCl:,_ t f? , -it1(?e~.eti tti ~thC{ tta~.; c' 1C'al' i!tllltci.l °ir7.i_'t S. 11',t ,tnicii.irc;Ouilt iu-ld r_n-oulu! ort a narro;e, site is c'011sI-1,11clccl "Olen t:akiii- tlic; ._lllcrtlate ,,isle setback alloev:ntcc. slhoulcl there he iirllits a11d rest nClio] ls OII tihc prox ifl lil.y ol,the basell.lellt ',%aI1 altd t11C ylav-at-loll to 1Cl~t)tf1171t1 properly 1 2. If an underground structure is allowed in the yard areas, should there be special rules for lot drainage regulations'? (BSC) .al}1c1, 18 nro-~,tle~ reLnllatiflo, CM. hltllclitl~~ ""l t.ll.1:Ia,lti allci c,}1Itrt~>lill~~. tilt 1'1.1rht_lif ratc ~~.acd orl a F per howl- raild"111. ` Ltb,s oll ~~l'ildc evils 131m isle a "i-nall arll<)t.;nt of pervious Ca 1.114el-lleaIil t:lhe I0I111datiolh 1Or ee',itcr ZO)sol`ptit_)n. 11'a 11111 1%l, cCnI I-it 1ti 1)1.111t. will 1111s I1113tICI the drallwgc 111 1 i~z,ilificallt lt cilt_)lt'?i1 11"1miller i() Ct.ll.tlrC: ;.Iddiiiolwi C1ralllal-)e I A`il.tr!.:ti ih(31 jltCJi; (l i!1 E l ij?tt`t 1 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) ;!I tine=d portlolli, .}l~;t.ttCtt.Irt~S lC)t:~1tCt1 .a 11)c 100 ;t~L`tll' llt odp1t1111 vd-licfl arc; 1)C'tti v lllc =;,e 11t)f)cI ciel atluri aI'c li{}t Al 1s)lt' it t.11h1C~s !!)",V Mice t tt'1r.c;'l i i tita}?11s}1cd ill ',CC1t)tl 12.E .i 1"1C 2001 1,Z{. a i } 11:t17Icr i A;'ti~1t A C i>i 9t C cltti' S Code of )1'C}tl?'tllc 1'.h+'1'i slit of .q 0 111i.a~11 r~,a`t.li s ,a}t`t (C? tt1 r 4. Should there be additional engineering criteria for the foundations of underground structures? (BSC) C of tl.c Code of Ordirla ices dcills ~.~~itl1 Ilc l'echrlu,:,11 Codes <illd ,llilclidniems w dlosc codes. `vVt;t 1. 11.15 nrllclldrrleruts dcalirl 7 1111 i"l,c111i1eI1It',11t" 1,01, ll*IT relit types of ~31.lu1dt:1C3CSrls. 13aserllerlt: ~~-all5 are l1ot: addi-ce Sc;d 111 1111" a rilerid1lielit. Section 8403 oC tl-le 1003 IRC tldi i' °tce sons ,aspC ctti o[ l7a St~;11C 111 col?strtlctiorl_ I)ut does not Address P ro\lrlllty to <id ztcc31t site..s. depth o xcm.;aiOli. ctc. 5. Should the area included within the walls of an underground structure be counted toward framed area? (ZPC) l.'ralllcd aria C1c.C111It1tIi1 131 :~illclC' of the L'.o{3 Ellice ltcx?lllaCl(llls ll.st" bayl'i1,c,i11s ti?t a cCl'tlll3l 01 ;aGd lesti 6.114111 8, t_'k dJHI l,ei"Ilt as Lull c\cllul?ti{')13 j!'? liiCl~lst(Fll lIl d tSalll4ll area calcl.tlLino] is. 6. Should the area included between the floor and ceiling of an underground structure be counted as a story? (ZPC) E C~ lrclll Cc1,.;tii?lI ~?E ;t s1ti)l4 it i17C' L~Iil l e "Tl3„Il~i .i~ ti1('01"I ;11C'I11(It Ole viE;171cI1l I tort' 1Cor r()1lupli;allcc a~-itli the ' 1. ,tfrv rtllc. li c;ertain b.lscllleruts do 111}1 count toy ard li")1iled area. tl3crl "ilot.tld dic.y he couwll d as a tor- ? Or if ~ve c:otim the ba5errleilt. area ils ! 410!-\,. "lloidd it be c tii)tcd tC)i~lsll"d the 1111\ii11!1J11 iiHov,,; Ihle Imiti d <irCa ) 7. What types of uses of an underground structure will be allowed? (ZPC or BSC) Al}b' li la?ii%l'L; os llod l?cl{)';i tt4:okl it i,'iitloll is kr)wed to pai"kinl1. i!CQ,,>s to the Strllctl_!l'e, Ll31tl `,tol`tvie. Ac llrullt it I)L's liti'llt to tlle.Se liSv~, 01111%, slid iiot allow amt'' 3ill)lt:lE)lt arcus ill a hase111:2nt.