diff --git a/src/components/floor-plan/modal/object/DormerOffset.jsx b/src/components/floor-plan/modal/object/DormerOffset.jsx
index fd3eb70a..1881b18e 100644
--- a/src/components/floor-plan/modal/object/DormerOffset.jsx
+++ b/src/components/floor-plan/modal/object/DormerOffset.jsx
@@ -1,4 +1,4 @@
-import { useState, useEffect, useRef } from 'react'
+import { useEffect, useRef, useState } from 'react'
 import { useMessage } from '@/hooks/useMessage'
 import WithDraggable from '@/components/common/draggable/WithDraggable'
 import { useRecoilValue } from 'recoil'
@@ -15,8 +15,8 @@ export default function DormerOffset(props) {
   const { closePopup } = usePopup()
   const [arrow1, setArrow1] = useState(null)
   const [arrow2, setArrow2] = useState(null)
-  const arrow1LengthRef = useRef()
-  const arrow2LengthRef = useRef()
+  const arrow1LengthRef = useRef(0)
+  const arrow2LengthRef = useRef(0)
   const [arrow1Length, setArrow1Length] = useState(0)
   const [arrow2Length, setArrow2Length] = useState(0)
 
@@ -59,12 +59,12 @@ export default function DormerOffset(props) {
                     name=""
                     label=""
                     className="input-origin block"
-                    value={arrow1LengthRef.current.value}
+                    value={arrow1LengthRef.current.value ?? 0}
                     ref={arrow1LengthRef}
                     onChange={(value) => setArrow1Length(value)}
                     options={{
                       allowNegative: false,
-                      allowDecimal: false
+                      allowDecimal: false,
                     }}
                   />
                 </div>