PVC windows for old Lithuanian project houses

Why replace windows in old Lithuanian project houses

Old Lithuanian project houses are often typical Soviet-era panel or masonry buildings. Original wooden frames or outdated aluminum windows with single glazing fail to provide sufficient thermal and acoustic insulation. Replacing windows with modern PVC constructions improves comfort, reduces heat loss and lowers heating bills.

Common issues with older windows

• Drafts and air leakage around the frame.
• Low thermal performance: single glazing or thin units.
• High outdoor noise transmission near roads and courtyards.
• Frame deformation and gaps due to building settlement and moisture.
• Installation challenges from non-standard openings in typical apartments.

Which PVC windows suit typical Soviet-era apartments

Profile and depth

• Choose a profile with 70–90 mm installation depth and at least 3–5 chambers for better insulation.
• For higher acoustic and structural demands, consider 6-chamber systems.

Insulating glass units

• A double-glazed unit with low-e coating and argon fill is the standard modern option.
• In colder climates or noisy locations, a triple-glazed unit with heavier panes is worthwhile.
• Consider multifunctional units that combine energy efficiency and sound reduction.

Hardware and ventilation

• Reliable hardware with micro-ventilation prevents the need for full opening during drafts.
• If the building lacks supply ventilation, add a frame-mounted trickle vent or provide mechanical ventilation in kitchen/bath.

Drainage and slopes

• Ensure the exterior sill and drainage are correctly sized to prevent water ingress into the joint.
• Insulate and finish interior slopes to avoid condensation build-up.

Installation and opening insulation

• Correct installation is crucial: foam should be applied only after proper anchoring and frame leveling.
• Use vapor and waterproofing tapes to eliminate thermal bridges and protect foam from moisture.
• In panel houses, leveling of slopes and mounting blocks is often necessary to hide gaps.

Specifics for Lithuanian project flats

• Openings can have non-standard dimensions: take precise on-site measurements.
• Balconies and loggias require separate solutions for thermal break and drainage.
• If the facade is in a heritage area, coordinate changes with local authorities and follow the facade appearance rules.

Cost, lead times and warranties

• The cost depends on window size, glass type and installation complexity; get an on-site estimate.
• Typical manufacturing time is 2–4 weeks; installation takes 1–2 days per window depending on scope.
• Profiles and hardware often carry 5+ year warranties; installation warranties usually start at 2 years. Get terms in writing.

Maintenance tips

• Lubricate moving parts every 6–12 months and check seals regularly.
• Avoid prolonged moisture exposure to slopes and joints.
• If condensation appears, check ventilation settings and consider micro-ventilation modes.

Pre-order checklist

• Exact opening dimensions and sill details.
• Required thermal and acoustic performance levels.
• Whether triple glazing is necessary or double glazing suffices.
• Opening type preferences (inward, tilt-and-turn, tilt-only).
• Need for approvals from homeowners association or heritage authorities.
• Confirm lead times and warranty conditions.

FAQ — common questions

1. Do I need permits to replace windows in an old building?

Usually no permits are needed if you do not change the facade or install external elements. If the building is in a protected zone, consult local authorities.

2. What U-value should new windows have?

For Baltic climates aim for U ≤ 1.3 W/m²K for standard windows and U ≤ 0.9 W/m²K for energy-efficient solutions.

3. Can I install PVC windows myself?

Installation is complex. Incorrect fit can lead to drafts and mold. Professional installation is recommended.

4. How long do modern PVC windows last?

With proper care, profiles and hardware can last 20+ years; insulating glass units typically last 15–25 years.

5. What about non-standard openings?

Custom-made windows are produced after on-site measurement by professionals.

Conclusion

Replacing old frames with modern PVC windows is one of the most effective upgrades for improving comfort in typical Lithuanian project houses. The right profile, glass unit and professional installation will reduce heating costs, lower noise levels and extend the service life of the window system.