Cost of ridge increase
Roof ridge heightening costs 2026
A roof ridge heightening costs on average between €10,000 and €30,000, depending on the size of your roof, the materials used, and whether you choose a traditional or prefab ridge heightening. In a ridge heightening, the ridge (the highest point of your roof) is raised or moved, creating extra living space in the attic. In this price guide, you can read exactly what a ridge heightening costs and what to look out for during the process.
Table of Contents
- How much does a ridge heightening cost?
- Costs of ridge heightening per material type
- Price-determining factors for a ridge heightening
- Additional costs and surcharges for a ridge heightening
- How does the professional work on a ridge heightening?
- How can you save on a ridge heightening?
- Common complications with a ridge heightening
- Find the best professional for a ridge heightening
- Frequently asked questions about a ridge heightening
- Book a professional for your ridge heightening
- Useful links
How much does a ridge heightening cost?
A ridge heightening costs on average between €13,000 and €21,000 for a standard sloped roof with a width of three metres. For a roof extension on a flat roof of approximately 25 square metres, the investment lies between €32,500 and €39,000. The costs for a ridge heightening are calculated per project and depend on the type of extension, the scale of the construction, and the chosen materials.
Average costs per type of ridge heightening
| Type of extension | Dimensions | Average costs |
|---|---|---|
| Shifted ridge sloped roof | three metres wide | €13,000 – €19,500 |
| Ridge heightening sloped roof | three metres wide | €16,000 – €21,000 |
| Flat roof extension | 25 m² | €32,500 – €39,000 |
With a shifted ridge, the ridge is moved sideways, providing extra height on one side. With a ridge heightening, the ridge is raised straight up, resulting in extra space on both sides. A roof extension on a flat roof requires more structural work and is therefore more expensive. The amounts above include 21% VAT and labour.
Costs of ridge heightening per material type
The costs for a ridge heightening vary per material type. Plastic is the most economical option and is often suitable for a prefab ridge heightening, while stone requires the highest investment due to the weight and extra reinforcements needed.
Costs of plastic ridge heightening
| Type of ridge heightening | Costs including labour and VAT |
|---|---|
| Shifted ridge | from €10,000 |
| Double-sided ridge heightening | from €16,000 |
Costs of wooden ridge heightening
| Type of ridge heightening | Costs including labour and VAT |
|---|---|
| Shifted ridge | from €11,000 |
| Double-sided ridge heightening | from €17,000 |
Costs of stone ridge heightening
| Type of ridge heightening | Costs including labour and VAT |
|---|---|
| Shifted ridge | from €13,000 |
| Double-sided ridge heightening | from €19,000 |
Price-determining factors for a ridge heightening
Several factors influence the costs for a ridge heightening.
Type of ridge heightening
A shifted ridge is cheaper than a double-sided ridge heightening. A shifted ridge moves the ridge to one side, gaining extra height on that side. This requires less material and labour time.
Material type
Plastic is the most affordable and lightweight enough to be installed without structural reinforcement. Wood offers a natural look but requires periodic maintenance. Stone matches the existing facade seamlessly but is heavier, almost always requiring reinforcement work.
Structural reinforcement
If the existing load-bearing structure cannot handle the extra load, beams or the foundation must be reinforced. This can increase costs by several thousand pounds.
Permit costs
An environmental permit is almost always required for a ridge heightening. Fees vary by municipality. Building drawings and structural calculations are also mandatory.
Additional costs and surcharges for a ridge heightening
Extra costs depend on the situation. At Zoofy, you do not pay call-out charges.
- Urgent jobs: If the professional must adjust their schedule for urgency, a surcharge often applies
- Weekend work: Activities during the weekend are more expensive than during the week
- Structural reinforcement: Necessary when the load-bearing capacity is insufficient
- Additional installations: Radiators, electrical sockets, and ventilation are often required in the new space
- Permit costs: Municipality fees plus blueprints and structural calculations
How does the professional work on a ridge heightening?
- Preparation and permit: Blueprints and structural calculations are made. The environmental permit is requested.
- Creating space: The professional removes the roofing material and insulation at the location.
- Checking and reinforcing the structure: The professional examines if the home can support the extra load.
- Installing the ridge heightening: Prefab is hoisted into place; custom work is built on-site.
- Finishing: Insulation, electricity, heating, and interior walls are installed during turn-key delivery.
How can you save on a ridge heightening?
- Choose prefab: Prefab ridge heightening is pre-made and faster to install, saving labour costs.
- Shell delivery: Have only the exterior finished and do the interior insulation and finishing yourself.
- Choose plastic: This is the most economical material option.
- Clear the attic: Empty the attic before the professional arrives so they can start immediately.
- Book through Zoofy: You get a fixed rate upfront without call-out charges.
Common complications with a ridge heightening
Structural weaknesses
In older homes, beams may be sagging or rotten. These must be reinforced before the ridge heightening can be placed.
Asbestos discovery
In roofs from before 1994, asbestos may be present. Removal by a certified company is mandatory, which increases costs.
Find the best professional for a ridge heightening
- Check insurance and references: Ask for reviews and ensure the contractor is insured.
- No call-out charges: You never pay extra for the professional's arrival.
- Fixed price upfront: Know exactly what the costs are without surprises.
- Payment via QR code: Pay only after the work is completed and you are satisfied.
Frequently asked questions about a ridge heightening
How long does it take to install a ridge heightening?
Execution takes 4-8 weeks on average, plus 2-4 weeks for finishing.
Is a ridge heightening permit-free?
No, an environmental permit is almost always required as the exterior appearance of the home changes.
What does it cost to raise your roof?
The costs for a double-sided ridge heightening on a sloped roof lie between €16,000 and €21,000.
Book a professional for your ridge heightening
Ready to have a ridge heightening carried out? At Zoofy, you can book a professional directly without quotes and without call-out charges. You pay only when the work is done.