Most small to medium-sized businesses spend thousands annually on HR software they barely use. Employee leave management systems are expensive, bloated with features no one needs, and require dedicated IT resources. But there's a better way: building custom workflows with tools you already own.
The Problem with Traditional HR Systems
Enterprise HR platforms like BambooHR, Namely, or Workday charge per employee per month, making them prohibitively expensive for teams under 100 people. For a 35-person organization processing fewer than 500 leave requests annually, these systems are massive overkill.
What businesses actually need is straightforward:
- A form where employees request time off
- Automated routing to the right manager for approval
- Email notifications at each stage
- A centralized log for auditing and reporting
- Integration with existing scheduling or workforce management tools
You can build all of this with Google Workspace and Zapier for a fraction of the cost.
Architecture: Building Blocks of a No-Code Leave System
The system consists of four interconnected components that handle the entire request-to-approval lifecycle.
1. Request Form (Google Forms)
Create a Google Form with these essential fields:
- Employee Name (automatically populated via Google SSO)
- Leave Type (dropdown: Vacation, Sick Leave, Personal, Bereavement, etc.)
- Start Date & End Date (date pickers with validation)
- Total Days (auto-calculated, excluding weekends)
- Manager/Approver (dropdown or auto-populated from organization structure)
- Reason/Notes (optional text field)
Pro tip: Use conditional logic in Google Forms to show different fields based on leave type. For example, sick leave might require a doctor's note after 3 consecutive days.
2. Central Database (Google Sheets)
Google Forms automatically pipes responses into a Google Sheet. Structure your sheet with these columns:
- Timestamp (auto-generated)
- Employee Email
- Leave Type, Start Date, End Date, Total Days
- Manager Email
- Status (Pending, Approved, Rejected, Requires More Info)
- Approval Date
- Notes/Comments
Add data validation rules to ensure consistency. The Status column should be a dropdown with only allowed values. Use color-coding with conditional formatting: green for Approved, red for Rejected, yellow for Pending.
3. Automation Layer (Zapier or Make)
This is where the workflow comes alive. Set up these automated workflows (Zaps):
Workflow 1: New Request Notification
- Trigger: New row added to Google Sheets
- Action 1: Send email to manager with request details and approve/reject links
- Action 2: Send confirmation email to employee
Workflow 2: Approval/Rejection Process
- Trigger: Manager clicks approve/reject link (webhook or email reply parsing)
- Action 1: Update Google Sheet status column
- Action 2: Send notification to employee with decision
- Action 3: If approved, trigger integration with scheduling system
Workflow 3: Multi-Level Approval (if needed)
- Trigger: Manager approves request
- Condition: If leave exceeds X days or certain leave type
- Action: Route to secondary approver (HR, department head)
4. Integration with External Systems
Connect your leave system to other business tools:
- Workforce Management (e.g., SimPro): Use API webhooks to sync approved leave with scheduling software
- Calendar (Google Calendar): Automatically block out approved leave dates on team calendars
- Slack/Teams: Post notifications to team channels when key people are out
- Payroll Systems: Export monthly leave data for payroll processing
Advanced Features to Consider
Once your basic workflow is running, enhance it with these power-user features:
Leave Balance Tracking
While the prompt mentioned accruals are out of scope, you can still add a simple balance tracker. Create a second sheet with employee names and remaining leave days. Use VLOOKUP formulas to check balance before approving requests.
Conflict Detection
Add logic to flag when multiple team members from the same department request overlapping dates. Prevent coverage gaps with automated warnings to managers.
Audit Trail & Compliance
Google Sheets automatically logs edit history, but for sensitive HR data, implement these safeguards:
- Protect sheet ranges so only HR can edit certain columns
- Enable version history and periodic backups to Google Drive
- Create a separate audit log sheet that timestamps every status change
Self-Service Dashboard
Build a simple web interface using Google Apps Script or a low-code platform like Glide or Softr. Give employees a dashboard to:
- View their leave history and remaining balance
- Check status of pending requests
- See team leave calendar to avoid conflicts
Cost Comparison: DIY vs. Commercial Solutions
Let's break down the economics for a 35-person team:
Commercial HR System:
- $8-15 per employee/month = $3,360-$6,300 annually
- Implementation fees: $1,000-5,000
- Training time: 10-20 hours across the organization
Google Workspace + Zapier Solution:
- Google Workspace: Already included (most businesses have this)
- Zapier Starter Plan: $240/year (more than enough tasks for 500 requests)
- Setup time: 8-12 hours for initial build + testing
- Total annual cost: ~$240 (96% savings)
Implementation Roadmap
Build this system incrementally over 2-3 weeks:
- Week 1: Core Workflow - Set up Google Form, Sheet, and basic Zapier automation for request submission and manager notification
- Week 2: Approval Logic - Build approval/rejection workflows with email triggers and status updates
- Week 3: Integration & Testing - Connect to external systems (calendar, scheduling software) and run user acceptance testing
- Ongoing: Refinement - Add advanced features based on user feedback and pain points
Common Mistakes to Avoid
- Over-engineering from the start: Launch with basic approve/reject flow, add complexity later
- Not testing edge cases: What happens if a manager is on leave? Who approves their requests?
- Forgetting mobile users: Managers often approve requests from their phones, test the mobile experience
- No documentation: Create a simple user guide for employees and troubleshooting doc for admins
- Ignoring data privacy: Ensure only HR and relevant managers have access to the master sheet
When to Graduate to a Commercial Solution
This DIY approach works brilliantly for small to medium teams, but you might outgrow it when:
- Your team exceeds 100 employees
- You need complex leave accrual policies across multiple countries
- Regulatory compliance requires certified HR software
- The system becomes too complex for non-technical staff to maintain
Conclusion
Building a custom leave management workflow with Google Workspace and Zapier gives you 90% of the functionality of expensive HR systems at 5% of the cost. For organizations processing hundreds, not thousands, of requests annually, this approach is faster to deploy, easier to customize, and trivial to maintain.
Start simple, iterate based on real usage, and only add complexity when you have concrete proof it's needed. Your employees will appreciate the streamlined process, your managers will appreciate the transparency, and your CFO will appreciate the cost savings.