Engineering systems are what hides inside walls, floors and risers — yet they decide whether a flat is safe and comfortable to live in. Cosmetic flaws are obvious at a glance; a mistake in the wiring or water layout only surfaces once the floor is laid and the wallpaper is up — and fixing it costs three times more.
This guide is for accepting a renovation from your contractor or inspecting a resale flat before buying. For each of the six systems — the key checkpoints, the norms and the warning signs. Much of it is visible with your eyes and a simple tester; some checks need instruments and a specialist.
⚡ 1. Electrical
The most common cause of serious trouble is cutting corners on wiring: undersized cable on a high-load circuit, twisted joints instead of proper connections, a breaker that doesn't match the cable. That's not cosmetic — it's a fire risk.
| What to check | Norm / what to look for | Tool |
|---|---|---|
| Panel & breakers | 220–230 V at the input; breakers trip; circuits labelled | Multimeter |
| Sockets | Live, neutral and earth present; polarity correct (live on the right) | Socket tester |
| Earthing (PE) | Resistance from socket to bus ≤ 1 Ω; PE never floating | Multimeter (Ω) |
| RCD / RCBO | TEST button trips instantly; trip leakage current ≤ rating | TEST button / meter |
| Junction-box joints | Twisted joints without solder/crimp/weld are prohibited; no heating | Inspection + thermal cam |
| Breaker vs cable size | 1.5 mm² → ≤ 16 A; 2.5 mm² → ≤ 25 A; 4 mm² → ≤ 32 A | Marking inspection |
| Mains voltage | 230 V ±10 % (207–253 V), measured at peak hours | Multimeter |
💧 2. Water supply & drainage
A hidden leak or a wrong drainage slope ruins a fresh renovation faster than anything. The system is checked under working pressure and by indirect signs.
| What to check | Norm / what to look for | Tool |
|---|---|---|
| Water pressure | Cold 2–4 bar, hot 1.5–3 bar | Pressure gauge |
| Tightness | With outlets closed, pressure holds 20–30 min without dropping | Pressure tester |
| Hot-water temperature | 55–60 °C at the tap; below 50 °C — legionella risk | Thermometer |
| Drainage & slope | A full bath (≥100 l) drains in 1–2 min with no pooling or smell | Visual |
| Soil vent pipe | Has draught, no sewage smell (mandatory with a toilet) | Sheet of paper |
| Shut-off valves | Ball valves turn a full 90°; flexible hoses under 10 years old | Inspection |
🔥 3. Heating
In an occupied flat you don't pressure-test the heating without draining it — you check it running: even heat-up and stable pressure.
| What to check | Norm / what to look for | Tool |
|---|---|---|
| Radiators | Even heating; flow/return difference 10–20 °C | IR thermometer |
| Bleed valves | Air bleeds out, then water flows — no air locks | Bleed key |
| System pressure | 1.5–2 bar on the boiler gauge; drop > 0.2 bar/day = hidden leak | Boiler gauge |
| Expansion vessel | Pre-charge 0.8–1.5 bar; 0 = burst membrane, replace | Pressure gauge |
| Safety valve | Present, free movement, no signs of discharge (puddles, scale) | Inspection |
| Underfloor heating | Even heat; surface ≤ 29 °C in living rooms, ≤ 26 °C in occupied zones | IR thermometer |
🌀 4. Ventilation
Poor ventilation isn't just stuffiness: above 65 % humidity, mould appears in corners and behind furniture, and CO₂ builds up in the air.
| What to check | Norm / what to look for | Tool |
|---|---|---|
| Extract draught | An A4 sheet holds to the grille; air speed ≥ 0.5 m/s | Paper / anemometer |
| Air flow rate | Kitchen with gas ≥ 90, electric ≥ 60 m³/h; bathroom ≥ 25–50 m³/h | Anemometer |
| Air quality | CO₂ ≤ 1000 ppm; humidity 40–60 % | CO₂ meter / hygrometer |
| Backdraught damper | Present on the extract — no neighbours' smells from the shaft | Inspection + paper |
| Supply-unit filters | G4 — replace 3–6 mo; F7–F9 — 6–12 mo; not grey/black | Inspection |
🔴 5. Gas supply
| What to check | Norm / what to look for | Tool |
|---|---|---|
| Inlet valve | In the right position, no rust, not seized | Inspection |
| Flexible hoses | No cracks or kinks; service life not expired | Inspection |
| Leak | Soap foam on joints — no bubbles | Soap solution |
| Boiler / heater | Pressure 1.5–2 bar, no errors on the display | Inspection |
| Gas / CO detector | TEST button works; calibration not overdue | TEST button |
| Flue | Has draught, no backdraught — otherwise CO poisoning risk | Draught gauge / service |
📡 6. Low-voltage systems
Internet, TV, intercom, fire and security alarms — usually checked last, and wrongly so: reworking them after the finish means chasing into finished walls.
| What to check | Norm / what to look for | Tool |
|---|---|---|
| Internet (twisted pair) | No breaks or crossed pairs; cabled speed as expected | Cable tester |
| TV signal | Level 45–75 dBμV, 75 Ω impedance, picture without breakup | TV signal meter |
| Intercom / video | Audio, lock release, clear image and night mode | Function test |
| Fire / security | TEST trips all zones; backup battery ≥ 24 h standby | Test mode |
| Equipment earthing | Amplifier, recorder, switch chassis earthed (≤ 1 Ω) | Multimeter |
The bottom line
Engineering isn't the line in the estimate to skimp on or take on trust. One circuit "on twisted joints", an undersized cable or a missing soil vent pipe isn't a cosmetic defect — it's a risk of leaks, fire or carbon-monoxide poisoning. Most problems are built in at the rough-in stage and then hidden under the finish.
If you're accepting a renovation or viewing a resale flat — walk through this list yourself or bring in a specialist with instruments. Inspecting the engineering takes a few hours and saves you from doing the renovation twice.
Frequently asked questions
What to check in an old apartment's wiring?
The wire type and gauge for the load, breakers by circuit group, RCDs and earthing. Old aluminium wiring is best replaced.
How do I know pipes need replacing?
By age, signs of leaks, rusty water and weak pressure. In a major renovation utilities are replaced before finishing — later it costs more.
Why does ventilation matter in a humid climate?
Without proper supply and extract, Georgia's humid climate produces condensation and mould. Check the draught and add forced ventilation if needed.
Who should inspect the engineering systems?
An engineer before work starts, with a report and photo record. Our engineer's assessment visit is free.
We'll build your engineering systems turnkey — or inspect the existing ones
An in-house team of 8 licensed tradespeople: electrical, water supply, heating, ventilation — no subcontractors, with as-built drawings. Tbilisi and Batumi.
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