Just Got BTO Keys? The 7-Day Aircon Installation Checklist Before You Move In
That moment when HDB hands you the keys. Years of waiting, ballot anxiety, construction updates on My HDBPage. Finally over. You’re standing in your empty flat. Bare walls. That new concrete smell. Mind already racing through Pinterest boards and renovation ideas. But here’s what we see happen too often. New BTO owners rush into aircon installation without proper planning. They book the cheapest installer. Skip the defect check. End up with units installed in wrong locations, undersized systems struggling to cool, or worse, HDB compliance issues that force them to redo everything. We’ve been installing aircon in new BTO flats across Singapore for years. The owners who do it right follow a system. Those who rush regret it within months. This 7-day checklist breaks down exactly what to do after collecting your BTO keys, specifically for aircon installation. Not generic advice. Specific steps that prevent expensive mistakes. Day 0: Key Collection Day – What Most People Miss You’ve just completed the appointment at HDB Hub. Keys in hand. Excitement through the roof. Before you do anything else, there’s critical information you need to gather. Most of it is in your HDB Welcome Kit, but people often toss it aside in their excitement. Check Your Flat’s Electrical Loading This determines what aircon system you can install. HDB flats built after January 1, 1994 (or those that underwent the Main Upgrading Programme or Home Improvement Programme) have 40-amp main switches. These flats can handle more powerful aircon systems without electrical upgrades. Older flats have 30-amp main switches. This creates a strict “power budget.” For example, a 4-room flat with 30-amp loading has a total running current cap of around 8.50 amps for all aircon units combined. You might be limited in what systems you can install. Your BTO is almost certainly a newer flat with 40-amp capacity. But verify this. The information is on HDB’s website, or you can check physically at your flat’s distribution board. Locate Your Aircon Ledge All new BTO flats come with a purpose-built concrete aircon ledge. This is the only approved location for your outdoor compressor. No exceptions. Find it. Photograph it. Note its size and position relative to your rooms. Why does this matter? The ledge location affects your piping routes, which affects installation cost and complexity. If the ledge is far from your master bedroom, expect longer pipe runs and higher costs. Get Your SP Services Account Ready You’ll need electricity for the defect inspection and any early work. SP Services requires at least one day to activate your account after application. Apply online before or immediately after key collection. Having power ready from Day 1 means you’re not scrambling later. Day 1: The Defect Inspection (Non-Negotiable) This step happens before any renovation. Before any aircon installation. Before anything. Every new BTO flat in Singapore comes with a 1-year Defects Liability Period (DLP) starting from the date of key collection. During this period, HDB will fix construction defects for free. The 30-Day Rule HDB strongly recommends reporting defects within 30 days of key collection and before renovation begins. Here’s why this matters for aircon. If your contractor drills holes for piping and later discovers a crack in the wall, who’s responsible? If your aircon installation happens first and then water seepage appears, was it the installation or a pre-existing defect? These disputes get messy. Avoid them by completing your defect inspection before any work starts. What to Check (Aircon-Relevant) While doing your full flat inspection, pay special attention to: The aircon ledge. Look for cracks, uneven surfaces, or drainage issues. Water should flow away from the building, not pool on the ledge. Walls where indoor units will be mounted. Tap them. Listen for hollow sounds that might indicate poor plastering. Check for visible cracks. The areas near windows where trunking will run. Any defects here should be fixed before your installer routes pipes through. Ceiling corners where drainage pipes might be installed. Water stains or dampness suggest existing issues. How to Report You’ll receive a Defects Feedback Form within 7 days of key collection. Fill it thoroughly. Take photos of everything. Submit to your estate’s Building Service Centre (BSC) or online through the HDB portal. Keep copies. You’ll need proof that defects existed before your renovation if disputes arise later. HDB typically completes rectification within 2 weeks. Plan your renovation timeline around this. Day 2-3: Planning Your Aircon System With defect inspection done or scheduled, now you plan the actual aircon system. This decision affects your comfort for the next 10-15 years. Choosing System 2, 3, or 4 New BTO flats only have space for one outdoor compressor on the aircon ledge. That’s why multi-split systems (one outdoor unit connected to multiple indoor units) are standard in Singapore HDB flats. The “System” number refers to how many indoor units connect to that single outdoor compressor. For 3-Room BTO (approximately 65-70 sqm): System 2 is typically sufficient. One unit for master bedroom, one for living room. If the second bedroom is regularly used (home office, child’s room), consider System 3. For 4-Room BTO (approximately 90 sqm): System 3 is the most common choice. Master bedroom, second bedroom, living room. Some owners go System 4 if they want all spaces air-conditioned. For 5-Room BTO (approximately 110 sqm): System 3 or System 4 depending on usage. Living rooms in 5-room flats need higher capacity units (12,000-18,000 BTU), while bedrooms work fine with 9,000 BTU. BTU Sizing Matters BTU (British Thermal Units) measures cooling capacity. Get this wrong and you’ll either have a unit struggling to cool (undersized) or one that short-cycles and creates clammy air (oversized). General Singapore guidelines: West-facing rooms need approximately 20-30% more BTU than these guidelines. If your master bedroom faces the afternoon sun, size up. Inverter vs Non-Inverter For 2025, there’s really only one answer: inverter technology. Inverter aircons adjust compressor speed based on room temperature. They use less energy, operate more quietly, and maintain more consistent temperatures. The upfront cost is higher,
Just Got BTO Keys? The 7-Day Aircon Installation Checklist Before You Move In Read More »











