# Villa Renovation in Sarıyer and Zekeriyaköy: Technical Details of Luxury - Exterior and Insulation
Sarıyer and especially the Zekeriyaköy region is one of Istanbul's most prestigious villa areas. In villas in these regions, exterior facade insulation and moisture control are critically important not only for comfort but also for structural lifespan and energy savings. In this guide, we address the exterior insulation techniques, moisture isolation solutions, and roof insulation details we use in Sarıyer villa renovation projects from a master's perspective.
Climate Characteristics of Sarıyer Region and Insulation Requirements
Sarıyer is one of Istanbul's regions with humid climate conditions. Especially in areas near the Bosphorus like Zekeriyaköy and Tarabya, humidity levels are high and structures may experience moisture problems.Moisture and Humidity Control: Why Critical?
In Sarıyer villas, humidity control is critically important for the following reasons:
1. Structural Lifespan: Moisture causes reinforcement (steel) corrosion in reinforced concrete structures
2. Health: High humidity leads to mold and fungus formation
3. Energy Savings: Uninsulated walls cause heat loss
4. Comfort: Humid environments reduce living comfort
Master's Note
In the Sarıyer region, especially in high-altitude areas like Zekeriyaköy, humidity levels can reach 80-90% in winter months. Therefore, exterior facade insulation must be done with waterproof (hydrophobic) materials.
Exterior Facade Insulation Materials: XPS Foam vs Stone Wool
In Sarıyer villa renovation projects, there are two main material options for exterior facade insulation: XPS foam and stone wool (mineral wool).
XPS (Extruded Polystyrene) Foam
XPS foam is an ideal option for humid climate conditions in the Sarıyer region.
XPS Foam Characteristics
- Waterproofing: Waterproof thanks to closed-cell structure
- Thermal conductivity: Lambda value 0.030-0.035 W/mK (lower than stone wool)
- Pressure resistance: Resistant to 200-700 kPa pressure
- Dimensional stability: Unaffected by moisture, does not change dimensions
XPS Foam Application Details
In Sarıyer villa exterior facade insulation, XPS foam application is done with the following steps:
1. Surface Preparation: Exterior facade wall is cleaned and smoothed
2. Adhesive Application: XPS panels are adhered to the wall with special adhesive
3. Fastening: Fixed with 6-8 plastic anchors per m²
4. Plaster Application: Fiberglass-reinforced plaster is applied on top
5. Exterior Facade Coating: Final coat plaster or exterior facade coating is applied
Master's Note
XPS foam thickness should be minimum 8 cm in the Sarıyer region. Thinner thickness (5-6 cm) does not provide adequate thermal insulation and energy savings target is not achieved.
In Zekeriyaköy villas, XPS foam insulation cost ranges from 1,200 - 1,800 TL per square meter (including thickness, surface preparation, and coating).
Stone Wool (Mineral Wool) Insulation
Stone wool is an environmentally friendly and superior insulation material in terms of fire safety.
Stone Wool Characteristics
- Breathable: High vapor permeability
- Fire safety: A1 class fire-resistant material
- Thermal conductivity: Lambda value 0.035-0.040 W/mK
- Sound insulation: Provides both thermal and sound insulation
Master's Note
Stone wool is less preferred than XPS foam in humid climates because it is water-absorbent. However, when applied correctly (together with waterproofing membrane), it can be successfully used in villas in the Tarabya region.
Moisture Isolation: Humidity Control in Walls
In Sarıyer villas, moisture problems are frequently seen, especially in old villas. The following techniques are applied for moisture control:
Moisture Isolation in Interior Walls
1. Waterproofing Membrane
For moisture control in interior walls, polyester felt-reinforced bitumen-based waterproofing membrane is applied. This membrane:
- Extended 20 cm upward at wall and floor joints
- Applied to interior wall surfaces
- Prevents moisture passage
2. Interior Wall Insulation
In interior walls, XPS foam or glass wool insulation is applied. This insulation:
- Prevents cold bridge formation
- Increases interior surface temperature
- Reduces condensation risk
Master's Note
In Zekeriyaköy villas, moisture problems are more frequently seen especially on north facade walls. On these walls, interior insulation must be applied.
Humidity Control in Windows
Window frames and glass are critical points in moisture passage.
Double/Triple Glazing Systems
In Sarıyer villas, double glazing (5+16+5 mm) or triple glazing (4+12+4+12+4 mm) systems should be used. Triple glazing systems:
- Provide better thermal insulation (U value: 0.6-0.8 W/m²K)
- Reduce condensation risk
- Provide energy savings (30-40%)
Window Frame Insulation
In window frame installation, special insulation tapes and foam should be used. Gaps between frame and wall should be filled with polyurethane foam.
Roof Insulation: Sloped and Flat Roof Solutions
In Sarıyer villas, roof insulation is critically important for energy savings. Different insulation techniques are applied according to roof type.
Sloped Roof Insulation
In Zekeriyaköy villas, sloped roofs are common. In sloped roof insulation:
1. Waterproofing Membrane
Under roof covering, waterproofing membrane is placed. This membrane:
- Prevents water leaks
- Provides vapor permeability (prevents condensation)
- Can be polyethylene or bitumen-based
2. Insulation Material
On waterproofing membrane, stone wool or glass wool insulation is placed. Thickness: minimum 10 cm.
Master's Note
In sloped roofs, insulation material is placed under roof covering (tiles, shingle). Interior roof (ceiling) insulation shows insufficient performance and leads to condensation problems.
Flat Roof Insulation
In Tarabya and İstinye villas, flat roofs are common. In flat roof insulation:
1. XPS Foam Insulation
On flat roof, XPS foam insulation is applied. Thickness: minimum 10 cm. XPS foam:
- Is waterproof (critical on flat roof)
- Is pressure resistant (walkable)
- Has high dimensional stability
2. Waterproofing Coating
On XPS foam, double-layer waterproofing coating is applied. This coating:
- Bitumen-based membrane (2 layers)
- Polyurethane coating
- EPDM membrane
Insulation Costs: 2026 Current Prices
Sarıyer villa insulation costs vary according to insulation type and villa size.Exterior Facade Insulation (XPS Foam, 8 cm)
- Zekeriyaköy: 1,500 - 2,000 TL/m²
- Tarabya, İstinye: 1,200 - 1,800 TL/m²
- Sarıyer Center: 1,000 - 1,600 TL/m²
Roof Insulation
- Sloped Roof (stone wool, 10 cm): 800 - 1,200 TL/m²
- Flat Roof (XPS foam, 10 cm + waterproofing): 1,500 - 2,500 TL/m²
Moisture Isolation (Interior Wall)
- Waterproofing Membrane: 150 - 250 TL/m²
- Interior Wall Insulation (XPS, 5 cm): 300 - 500 TL/m²
Frequently Asked Questions (FAQ)
Is exterior facade insulation mandatory?
In the Sarıyer region, exterior facade insulation is definitely recommended for energy savings and moisture control. Mandatory status varies according to municipality and building condition.
Should XPS foam or stone wool be preferred?
In humid climates (e.g., Sarıyer), XPS foam is a more suitable option. If fire safety is a priority, stone wool is preferred.
How is moisture problem solved?
Moisture problem is solved with a combination of exterior facade insulation + interior wall insulation + waterproofing membrane.
Conclusion: Get Professional Support
Exterior facade insulation and moisture control in Sarıyer and Zekeriyaköy villas is a technical process requiring expertise. With over 15 years of experience, we offer solutions that will extend your villa's structural lifespan and provide energy savings.
By booking a free site visit appointment, you can get detailed insulation analysis and cost proposal for your villa. Free Architectural Site Visit Line: 0501 022 33 75
