diff --git a/extract/ExtCouple.c b/extract/ExtCouple.c
index 3d681b39..1be1032c 100644
--- a/extract/ExtCouple.c
+++ b/extract/ExtCouple.c
@@ -867,15 +867,8 @@ extSideOverlap(tp, esws)
     }
 
     /* Add in the new capacitance. */
-    if (tb == TT_SPACE)
-    {
-	/* Is tp a space tile?  If so, extGetRegion points to garbage;
-	 * make terminal 2 point to ground.
-	 */
-	rbp->nreg_cap += cap;
-	if (CAP_DEBUG) extNregAdjustCap(rbp, cap, "sideoverlap_to_subs");
-    }
-    else
+
+    if (tb != TT_SPACE)
     {
 	int oa = ExtCurStyle->exts_planeOrder[esws->plane_of_boundary];
 	int ob = ExtCurStyle->exts_planeOrder[esws->plane_checked];
@@ -900,12 +893,13 @@ extSideOverlap(tp, esws)
 	    rbp->nreg_cap -= subcap;
 	    /* Ignore residual error at ~zero zeptoFarads.  Probably	*/
 	    /* there should be better handling of round-off here.	*/
-	    if ((rbp->nreg_cap > -0.001) && (rbp->nreg_cap < 0.001)) rbp->nreg_cap = 0;
+	    if ((rbp->nreg_cap > -0.001) && (rbp->nreg_cap < 0.001))
+		rbp->nreg_cap = 0;
 	    if (CAP_DEBUG)
-		extNregAdjustCap(rbp, -subcap, "obsolete_perimcap");
-	} else if (CAP_DEBUG)
-	    extNregAdjustCap(rbp, 0.0,
-		"obsolete_perimcap (skipped, wrong direction)");
+	    	extNregAdjustCap(rbp, -subcap, "obsolete_perimcap");
+    	}
+	else if (CAP_DEBUG)
+	    extNregAdjustCap(rbp, 0.0, "obsolete_perimcap (skipped, wrong direction)");
 
 	/* If the nodes are electrically connected, then we don't add	*/
 	/* any side overlap capacitance to the node.			*/
diff --git a/extract/ExtTech.c b/extract/ExtTech.c
index f533198c..42892c9a 100644
--- a/extract/ExtTech.c
+++ b/extract/ExtTech.c
@@ -1242,9 +1242,9 @@ ExtTechSimplePerimCap(argc, argv)
 
     DBTechNoisyNameMask(argv[1], &types);
     TTMaskSetMask(allExtractTypes, &types);
-    TTMaskZero(&nottypes);
-    TTMaskSetType(&nottypes, TT_SPACE);
     plane1 = DBTechNoisyNamePlane(argv[2]);
+
+    TTMaskCom2(&nottypes, &types);
     TTMaskAndMask(&types, &DBPlaneTypes[plane1]);
     TTMaskAndMask(&nottypes, &DBPlaneTypes[plane1]);
 
@@ -1260,8 +1260,13 @@ ExtTechSimplePerimCap(argc, argv)
 	DBTechNoisyNameMask(argv[argc - 3], &subtypes);
 	TTMaskSetMask(allExtractTypes, &subtypes);
     }
-    else
+    else if (ExtCurStyle->exts_globSubstratePlane != -1)
+    {
 	TTMaskZero(&subtypes);
+	TTMaskSetMask(&subtypes, &ExtCurStyle->exts_globSubstrateTypes);
+    }
+    else
+	TTMaskSetOnlyType(&subtypes, TT_SPACE);
 
     /* Part 1: Perimeter cap */
 
@@ -1328,6 +1333,9 @@ ExtTechSimplePerimCap(argc, argv)
 
 	    TTMaskClearType(&subtypes, ExtCurStyle->exts_globSubstrateDefaultType);
 
+	    /* But space is */
+	    TTMaskSetType(&subtypes, TT_SPACE);
+
 	    /* All types on the substrate plane that are not substrate	*/
 	    /* are by definition shielding types.			*/
 
@@ -1352,9 +1360,7 @@ ExtTechSimplePerimCap(argc, argv)
 	    TTMaskSetMask(&ExtCurStyle->exts_sideEdges[s], &nottypes);
 	    for (t = 0; t < DBNumTypes; t++)
 	    {
-		if (!TTMaskHasType(&nottypes, t))
-		    continue;
-
+		if (!TTMaskHasType(&nottypes, t)) continue;
   		if (DBIsContact(t)) continue;
 
 		TTMaskSetMask(&ExtCurStyle->exts_sideOverlapOtherTypes[s][t], &subtypes);
@@ -1377,33 +1383,6 @@ ExtTechSimplePerimCap(argc, argv)
 			ExtCurStyle->exts_sideOverlapShieldPlanes[s][r] |= pshield;
 	    }
 	}
-
-	/* Reverse case (swap "types" and "subtypes") */
-
-	if ((plane2 != -1) && TTMaskHasType(&subtypes, s))
-	{
-	    ExtCurStyle->exts_sidePlanes |= PlaneNumToMaskBit(plane2);
-	    TTMaskSetType(&ExtCurStyle->exts_sideTypes[plane2], s);
-	    for (t = TT_TECHDEPBASE; t < DBNumTypes; t++)
-	    {
-  		if (DBIsContact(t)) continue;
-
-		TTMaskSetMask(&ExtCurStyle->exts_sideOverlapOtherTypes[s][t], &types);
-		ExtCurStyle->exts_sideOverlapOtherPlanes[s][t] |=
-				PlaneNumToMaskBit(plane1);
-		cnew = (EdgeCap *) mallocMagic((unsigned) (sizeof (EdgeCap)));
-		cnew->ec_cap = capVal;
-		cnew->ec_far = shields;		/* Types that shield */
-		cnew->ec_near = types;		/* Types we create cap with */
-		cnew->ec_pmask = PlaneNumToMaskBit(plane1);
-		cnew->ec_next = ExtCurStyle->exts_sideOverlapCap[s][t];
-		ExtCurStyle->exts_sideOverlapCap[s][t] = cnew;
-
-		for (r = TT_TECHDEPBASE; r < DBNumTypes; r++)
-		    if (TTMaskHasType(&types, r))
-			ExtCurStyle->exts_sideOverlapShieldPlanes[s][r] |= pshield;
-	    }
-	}
     }
 }
 
@@ -1611,10 +1590,7 @@ ExtTechSimpleSideOverlapCap(argv)
     TTMaskSetMask(allExtractTypes, &types);
     plane1 = DBTechNoisyNamePlane(argv[2]);
 
-    // TTMaskCom2(&nottypes, &types);
-    TTMaskZero(&nottypes);
-    TTMaskSetType(&nottypes, TT_SPACE);
-
+    TTMaskCom2(&nottypes, &types);
     TTMaskAndMask(&types,    &DBPlaneTypes[plane1]);
     TTMaskAndMask(&nottypes, &DBPlaneTypes[plane1]);
 
@@ -1655,12 +1631,12 @@ ExtTechSimpleSideOverlapCap(argv)
     for (plane3 = PL_TECHDEPBASE; plane3 < DBNumPlanes; plane3++)
     {
 	pnum3 = ExtCurStyle->exts_planeOrder[plane3];
-	if ((forward == TRUE) && (pnum3 > pnum2 && pnum3 < pnum1))
+	if ((forward == FALSE) && (pnum3 > pnum2 && pnum3 < pnum1))
 	{
 	    TTMaskSetMask(&shields, &DBPlaneTypes[plane3]);
 	    pshield |= PlaneNumToMaskBit(plane3);
 	}
-	else if ((forward == FALSE) && (pnum3 < pnum2 && pnum3 > pnum1))
+	else if ((forward == TRUE) && (pnum3 < pnum2 && pnum3 > pnum1))
 	{
 	    TTMaskSetMask(&shields, &DBPlaneTypes[plane3]);
 	    pshield |= PlaneNumToMaskBit(plane3);