When to replace old windows with new PVC

When to replace old windows with new PVC

Old wooden or aluminum windows with worn seals, single glazing, or rotten frames are common causes of heat loss, drafts and increased indoor humidity. Replacing them with modern PVC windows improves comfort, reduces energy bills and increases sound insulation.

Signs it's time to replace windows

• Noticeable drafts or cold spots near the window.
• Persistent condensation inside the glass units or moisture on the frame.
• Difficulty opening/closing sashes, sagging or distorted frames.
• Cracked glass or old single-pane windows with poor thermal performance.
• Increased street noise reaching the interior.
• High heating costs and cold glass surfaces.

If windows are older than 20–25 years or several of these signs appear, consider replacement.

Why PVC is a good choice

• Energy efficiency: modern double- and triple-glazed units significantly reduce heat loss.
• Airtightness: quality gaskets eliminate drafts and moisture ingress.
• Noise reduction: the profile and glazing reduce external noise.
• Durability: PVC does not rot and does not require regular painting.
• Low maintenance: periodic cleaning and occasional hardware lubrication are enough.

When replacement makes financial sense

• Heating costs are substantially higher than average for the building.
• You are doing major renovations—window replacement pairs well with interior works.
• Facade upgrades or balcony glazing are planned.
• You plan to sell or rent the apartment—new windows increase value and appeal.

How to choose the system

1. Determine required thermal performance: warm-edge spacer, Low-E glass, argon or krypton fill.
2. Choose the profile: 3–5 chamber profiles for residential use; more chambers increase insulation.
3. Hardware options: micro-ventilation, anti-burglary fittings, child safety locks.
4. Glazing: double glazing for moderate climates, triple glazing for colder regions or north-facing rooms.
5. Finish and color: wood-effect lamination or plain colors to match the interior.

Installation: what matters

• Proper sealing with a warm installation joint: foam + internal vapor barrier + external waterproofing.
• Window sills and trims installed correctly to avoid thermal bridges.
• Check the opening geometry: uneven openings require preparation work.
• Warranties: confirm both product and installation guarantees and service terms.

FAQ

How long do old windows and PVC windows last?

Old wooden windows, with maintenance, can last 30–50 years but become energetically obsolete after 20–30 years. Well-made PVC windows typically last 30–40 years or more with proper care.

How to tell if the issue is the glazing unit or the frame/installation?

Condensation between glass panes indicates failed glazing seals. Condensation on internal sills and frames often points to poor ventilation or thermal bridges around the opening.

How long does a typical replacement take?

Replacing 3–4 standard windows in an apartment usually takes 1–2 working days. Complex openings, balconies or facade work extend the timeframe.

Do I need permits to replace windows in an apartment building?

Internal replacements typically don't require permits. If the facade’s appearance changes (color or shape), many buildings or historic areas require approval from the HOA or municipality.

Can windows be installed in winter?

Yes, installation is possible in winter if the correct materials and techniques are used (warm joints, suitable foams and tapes). Some finishing tasks are easier in mild weather.

What happens to old windows?

Old frames and glass should be recycled via specialized facilities. Many installers offer removal and disposal services as part of the installation package.

How to maintain new PVC windows?

Clean gaskets and glass with mild detergent and water, lubricate hardware 1–2 times a year, check seals and adjust sashes if they sag.

Quick tips from DK-Logi

• Start with an energy audit or thermal camera inspection to identify cold bridges.
• If budget is limited, replace the worst-performing windows first and plan the rest over several years.
• Choose certified suppliers and professional installers to secure long-term performance.