PVC windows for 104 series: practical advice

Introduction

Replacing or installing PVC windows in a typical 104-series apartment requires special attention to opening geometry, insulation, and ventilation. This guide offers practical recommendations on choosing a frame, glazing, installation method and maintenance to ensure warm, airtight, and long-lasting windows without unnecessary cost.

Why the 104 series is particular

• 104-series are panel buildings with standard openings and relatively thin reveals.
• Non-standard angles and slight deformations of openings are common, leaving limited space for sills and fittings.
• It's important to consider load-bearing elements and not to block building ventilation systems.

Preparation

Measurements and inspection

• Order a professional measurement: millimeter precision is essential for a tight fit and proper installation.
• Check vertical and horizontal alignment: severe deviations may require adapter trims or additional work.
• Inspect window reveals and sills — you may need to remove old finishes and level the surfaces.

Profile selection and reinforcement

• For 104 series apartments, 3- to 5-chamber profiles are usually sufficient for living areas; choose 5 or more chambers for better thermal performance.
• Pay attention to steel reinforcement and wall thickness of the profile — they affect sash rigidity and lifespan.

Glass units: double or triple glazing?

• A standard choice is a double-glazed unit with Low-E glass and argon filling for better insulation.
• Consider a triple-glazed unit for cold-facing windows or large openings.
• Sound insulation and solar control depend on glass type: laminated, tinted, or reflective options may be used.

Installation: key points

• A "warm" installation approach (using installation foam and internal/external vapor barriers) is recommended for apartments.
• Use mechanical anchors and mounting plates; apply foam sparingly — excess foam can distort frames.
• Maintain the correct division of the mounting joint: exterior layer should be water-repellent, interior layer vapor-tight.
• Fit sills and drip profiles with a slight outward slope to direct water away.

Incorrect installation is the main reason for condensation, drafts, and premature seal failure.

Ventilation and micro-ventilation

• In 104-series flats ensure fresh air supply: consider built-in micro-ventilation vents or trickle vents in the reveal.
• Do not seal or block communal ventilation without assessment — this can lead to high humidity and mold.

Maintenance

• Lubricate hardware annually and inspect seals for wear; replace if compressed or cracked.
• Clean glass with mild detergents; avoid abrasive cleaners and harsh solvents.
• In winter check drainage and insulation to prevent freeze damage to joints.

Cost and payback

• Price depends on profile, glass unit, and installation complexity. In 104 series, additional work like reveal leveling often raises cost.
• Energy savings and improved comfort make the investment pay off over time.

FAQ — Common questions

Do I need permission to replace windows in a 104 series building?

• Internal window replacements usually don’t require permission. If you change the façade, external sills, or opening dimensions, consult building management or the co-op.

How long does installation take?

• Measurement and selection: 1–3 days.
• Manufacturing: typically 7–21 days depending on specifications.
• Installation: usually 1–2 days for an apartment, depending on the scope and removal of old elements.

How to avoid condensation?

• Proper installation with correct vapor and water seals.
• Ensure adequate ventilation via micro-vents or regular airing.

Replace the whole window block or only the frame?

• Full replacement is recommended for deformed openings or poor insulation.
• Replacing only the frame is possible for good condition openings but needs precise measurements.

How to choose hardware?

• Choose known brands with adjustable fittings and anti-burglary options if needed.

Should I insulate the reveals?

• Yes. Properly insulated and sealed reveals reduce heat loss and condensation risk.

Tips to save money

• Get multiple quotes, check scope of works and warranties. The cheapest offer may cost more due to rework.

Conclusion

Correct selection and professional installation of PVC windows in a 104-series apartment improves comfort and lowers heating bills. Use precise measurements, quality profiles and experience-based installers to achieve a durable and effective result.