diff --git a/scripts/bash/common.sh b/scripts/bash/common.sh
index c332ceb88..416fcadfc 100644
--- a/scripts/bash/common.sh
+++ b/scripts/bash/common.sh
@@ -1,15 +1,48 @@
 #!/usr/bin/env bash
 # Common functions and variables for all scripts
 
-# Get repository root, with fallback for non-git repositories
+# Find repository root by searching upward for .specify directory
+# This is the primary marker for spec-kit projects
+find_specify_root() {
+    local dir="${1:-$(pwd)}"
+    # Normalize to absolute path to prevent infinite loop with relative paths
+    # Use -- to handle paths starting with - (e.g., -P, -L)
+    dir="$(cd -- "$dir" 2>/dev/null && pwd)" || return 1
+    local prev_dir=""
+    while true; do
+        if [ -d "$dir/.specify" ]; then
+            echo "$dir"
+            return 0
+        fi
+        # Stop if we've reached filesystem root or dirname stops changing
+        if [ "$dir" = "/" ] || [ "$dir" = "$prev_dir" ]; then
+            break
+        fi
+        prev_dir="$dir"
+        dir="$(dirname "$dir")"
+    done
+    return 1
+}
+
+# Get repository root, prioritizing .specify directory over git
+# This prevents using a parent git repo when spec-kit is initialized in a subdirectory
 get_repo_root() {
+    # First, look for .specify directory (spec-kit's own marker)
+    local specify_root
+    if specify_root=$(find_specify_root); then
+        echo "$specify_root"
+        return
+    fi
+
+    # Fallback to git if no .specify found
     if git rev-parse --show-toplevel >/dev/null 2>&1; then
         git rev-parse --show-toplevel
-    else
-        # Fall back to script location for non-git repos
-        local script_dir="$(CDPATH="" cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
-        (cd "$script_dir/../../.." && pwd)
+        return
     fi
+
+    # Final fallback to script location for non-git repos
+    local script_dir="$(CDPATH="" cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+    (cd "$script_dir/../../.." && pwd)
 }
 
 # Get current branch, with fallback for non-git repositories
@@ -20,14 +53,14 @@ get_current_branch() {
         return
     fi
 
-    # Then check git if available
-    if git rev-parse --abbrev-ref HEAD >/dev/null 2>&1; then
-        git rev-parse --abbrev-ref HEAD
+    # Then check git if available at the spec-kit root (not parent)
+    local repo_root=$(get_repo_root)
+    if has_git; then
+        git -C "$repo_root" rev-parse --abbrev-ref HEAD
         return
     fi
 
     # For non-git repos, try to find the latest feature directory
-    local repo_root=$(get_repo_root)
     local specs_dir="$repo_root/specs"
 
     if [[ -d "$specs_dir" ]]; then
@@ -68,9 +101,17 @@ get_current_branch() {
     echo "main"  # Final fallback
 }
 
-# Check if we have git available
+# Check if we have git available at the spec-kit root level
+# Returns true only if git is installed and the repo root is inside a git work tree
+# Handles both regular repos (.git directory) and worktrees/submodules (.git file)
 has_git() {
-    git rev-parse --show-toplevel >/dev/null 2>&1
+    # First check if git command is available (before calling get_repo_root which may use git)
+    command -v git >/dev/null 2>&1 || return 1
+    local repo_root=$(get_repo_root)
+    # Check if .git exists (directory or file for worktrees/submodules)
+    [ -e "$repo_root/.git" ] || return 1
+    # Verify it's actually a valid git work tree
+    git -C "$repo_root" rev-parse --is-inside-work-tree >/dev/null 2>&1
 }
 
 check_feature_branch() {
diff --git a/scripts/bash/create-new-feature.sh b/scripts/bash/create-new-feature.sh
index 0df4adc3e..579d34752 100644
--- a/scripts/bash/create-new-feature.sh
+++ b/scripts/bash/create-new-feature.sh
@@ -80,19 +80,6 @@ if [ -z "$FEATURE_DESCRIPTION" ]; then
     exit 1
 fi
 
-# Function to find the repository root by searching for existing project markers
-find_repo_root() {
-    local dir="$1"
-    while [ "$dir" != "/" ]; do
-        if [ -d "$dir/.git" ] || [ -d "$dir/.specify" ]; then
-            echo "$dir"
-            return 0
-        fi
-        dir="$(dirname "$dir")"
-    done
-    return 1
-}
-
 # Function to get highest number from specs directory
 get_highest_from_specs() {
     local specs_dir="$1"
@@ -171,21 +158,16 @@ clean_branch_name() {
     echo "$name" | tr '[:upper:]' '[:lower:]' | sed 's/[^a-z0-9]/-/g' | sed 's/-\+/-/g' | sed 's/^-//' | sed 's/-$//'
 }
 
-# Resolve repository root. Prefer git information when available, but fall back
-# to searching for repository markers so the workflow still functions in repositories that
-# were initialised with --no-git.
+# Resolve repository root using common.sh functions which prioritize .specify over git
 SCRIPT_DIR="$(CDPATH="" cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
 source "$SCRIPT_DIR/common.sh"
 
-if git rev-parse --show-toplevel >/dev/null 2>&1; then
-    REPO_ROOT=$(git rev-parse --show-toplevel)
+REPO_ROOT=$(get_repo_root)
+
+# Check if git is available at this repo root (not a parent)
+if has_git; then
     HAS_GIT=true
 else
-    REPO_ROOT="$(find_repo_root "$SCRIPT_DIR")"
-    if [ -z "$REPO_ROOT" ]; then
-        echo "Error: Could not determine repository root. Please run this script from within the repository." >&2
-        exit 1
-    fi
     HAS_GIT=false
 fi
 
diff --git a/scripts/powershell/common.ps1 b/scripts/powershell/common.ps1
index 1595bd8a0..c67097773 100644
--- a/scripts/powershell/common.ps1
+++ b/scripts/powershell/common.ps1
@@ -1,7 +1,38 @@
 #!/usr/bin/env pwsh
 # Common PowerShell functions analogous to common.sh
 
+# Find repository root by searching upward for .specify directory
+# This is the primary marker for spec-kit projects
+function Find-SpecifyRoot {
+    param([string]$StartDir = (Get-Location).Path)
+
+    # Normalize to absolute path to prevent issues with relative paths
+    # Use -LiteralPath to handle paths with wildcard characters ([, ], *, ?)
+    $current = (Resolve-Path -LiteralPath $StartDir -ErrorAction SilentlyContinue)?.Path
+    if (-not $current) { return $null }
+
+    while ($true) {
+        if (Test-Path -LiteralPath (Join-Path $current ".specify") -PathType Container) {
+            return $current
+        }
+        $parent = Split-Path $current -Parent
+        if ([string]::IsNullOrEmpty($parent) -or $parent -eq $current) {
+            return $null
+        }
+        $current = $parent
+    }
+}
+
+# Get repository root, prioritizing .specify directory over git
+# This prevents using a parent git repo when spec-kit is initialized in a subdirectory
 function Get-RepoRoot {
+    # First, look for .specify directory (spec-kit's own marker)
+    $specifyRoot = Find-SpecifyRoot
+    if ($specifyRoot) {
+        return $specifyRoot
+    }
+
+    # Fallback to git if no .specify found
     try {
         $result = git rev-parse --show-toplevel 2>$null
         if ($LASTEXITCODE -eq 0) {
@@ -10,9 +41,10 @@ function Get-RepoRoot {
     } catch {
         # Git command failed
     }
-    
-    # Fall back to script location for non-git repos
-    return (Resolve-Path (Join-Path $PSScriptRoot "../../..")).Path
+
+    # Final fallback to script location for non-git repos
+    # Use -LiteralPath to handle paths with wildcard characters
+    return (Resolve-Path -LiteralPath (Join-Path $PSScriptRoot "../../..")).Path
 }
 
 function Get-CurrentBranch {
@@ -20,19 +52,21 @@ function Get-CurrentBranch {
     if ($env:SPECIFY_FEATURE) {
         return $env:SPECIFY_FEATURE
     }
-    
-    # Then check git if available
-    try {
-        $result = git rev-parse --abbrev-ref HEAD 2>$null
-        if ($LASTEXITCODE -eq 0) {
-            return $result
-        }
-    } catch {
-        # Git command failed
-    }
-    
-    # For non-git repos, try to find the latest feature directory
+
+    # Then check git if available at the spec-kit root (not parent)
     $repoRoot = Get-RepoRoot
+    if (Test-HasGit) {
+        try {
+            $result = git -C $repoRoot rev-parse --abbrev-ref HEAD 2>$null
+            if ($LASTEXITCODE -eq 0) {
+                return $result
+            }
+        } catch {
+            # Git command failed
+        }
+    }
+
+    # For non-git repos, try to find the latest feature directory
     $specsDir = Join-Path $repoRoot "specs"
     
     if (Test-Path $specsDir) {
@@ -69,9 +103,23 @@ function Get-CurrentBranch {
     return "main"
 }
 
+# Check if we have git available at the spec-kit root level
+# Returns true only if git is installed and the repo root is inside a git work tree
+# Handles both regular repos (.git directory) and worktrees/submodules (.git file)
 function Test-HasGit {
+    # First check if git command is available (before calling Get-RepoRoot which may use git)
+    if (-not (Get-Command git -ErrorAction SilentlyContinue)) {
+        return $false
+    }
+    $repoRoot = Get-RepoRoot
+    # Check if .git exists (directory or file for worktrees/submodules)
+    # Use -LiteralPath to handle paths with wildcard characters
+    if (-not (Test-Path -LiteralPath (Join-Path $repoRoot ".git"))) {
+        return $false
+    }
+    # Verify it's actually a valid git work tree
     try {
-        git rev-parse --show-toplevel 2>$null | Out-Null
+        $null = git -C $repoRoot rev-parse --is-inside-work-tree 2>$null
         return ($LASTEXITCODE -eq 0)
     } catch {
         return $false
diff --git a/scripts/powershell/create-new-feature.ps1 b/scripts/powershell/create-new-feature.ps1
index 473c925b9..9adae131d 100644
--- a/scripts/powershell/create-new-feature.ps1
+++ b/scripts/powershell/create-new-feature.ps1
@@ -45,30 +45,6 @@ if ([string]::IsNullOrWhiteSpace($featureDesc)) {
     exit 1
 }
 
-# Resolve repository root. Prefer git information when available, but fall back
-# to searching for repository markers so the workflow still functions in repositories that
-# were initialized with --no-git.
-function Find-RepositoryRoot {
-    param(
-        [string]$StartDir,
-        [string[]]$Markers = @('.git', '.specify')
-    )
-    $current = Resolve-Path $StartDir
-    while ($true) {
-        foreach ($marker in $Markers) {
-            if (Test-Path (Join-Path $current $marker)) {
-                return $current
-            }
-        }
-        $parent = Split-Path $current -Parent
-        if ($parent -eq $current) {
-            # Reached filesystem root without finding markers
-            return $null
-        }
-        $current = $parent
-    }
-}
-
 function Get-HighestNumberFromSpecs {
     param([string]$SpecsDir)
     
@@ -139,26 +115,14 @@ function ConvertTo-CleanBranchName {
     
     return $Name.ToLower() -replace '[^a-z0-9]', '-' -replace '-{2,}', '-' -replace '^-', '' -replace '-$', ''
 }
-$fallbackRoot = (Find-RepositoryRoot -StartDir $PSScriptRoot)
-if (-not $fallbackRoot) {
-    Write-Error "Error: Could not determine repository root. Please run this script from within the repository."
-    exit 1
-}
-
-# Load common functions (includes Resolve-Template)
+# Load common functions (includes Get-RepoRoot, Test-HasGit, Resolve-Template)
 . "$PSScriptRoot/common.ps1"
 
-try {
-    $repoRoot = git rev-parse --show-toplevel 2>$null
-    if ($LASTEXITCODE -eq 0) {
-        $hasGit = $true
-    } else {
-        throw "Git not available"
-    }
-} catch {
-    $repoRoot = $fallbackRoot
-    $hasGit = $false
-}
+# Use common.ps1 functions which prioritize .specify over git
+$repoRoot = Get-RepoRoot
+
+# Check if git is available at this repo root (not a parent)
+$hasGit = Test-HasGit
 
 Set-Location $repoRoot