Extension

The costs of a home renovation vary widely, depending on the type of work, the materials used, the scope of the project, and labor costs. An accurate cost estimate is essential for realistic planning and financing.

1. Average Indicative Prices per Renovation Type

2. Renovation Cost Breakdown

An average renovation consists of the following cost categories:

The final distribution depends on the project type, complexity, and the degree of self-employment.

3. Factors affecting costs

• Scope and complexity of the project
• Accessibility of the workplace (e.g., floors, limited workspace)
• Type of materials (standard vs. luxury finish)
• Permit requirement and additional structural requirements

4. Unforeseen Costs

When renovating, always set aside a reserve of approximately 10% to 15% for unforeseen items such as:

• Additional work during demolition (e.g. rotten beams, asbestos)
• Delays due to delivery times or weather conditions
• Adaptation of pipework or installations

5. Savings tips for renovation costs

• Combine tasks where possible
• Request multiple quotes and compare specifications
• Investigate subsidy options (such as ISDE or municipal regulations)
• Consider doing parts of the project yourself (such as demolition or painting)
• Choose standard materials or leftover stock from suppliers

Conclusion
The costs of a renovation are highly dependent on choices in design, finishes, technical requirements, and execution method. A clear budget, supplemented by a realistic buffer for unforeseen costs, prevents financial disappointments and provides control over the process.

A renovation involves many choices and responsibilities. Whether it's an extension, renovation or reorganisation, a structured approach prevents delays, cost overruns and ambiguities. The step-by-step plan below provides an overview of all the necessary phases for a successful renovation.

Step 1: Objective and needs assessment

• Determine the exact purpose of the renovation: comfort, space, energy performance, aesthetics.
• Make an inventory of wishes and requirements per room.
• Set priorities: what is necessary and what is optional?

Step 2: Orientation and budget estimation

• Gather information about materials, solutions and prices.
• Request indicative target prices from contractors or specialised companies.
• Draw up a realistic budget, including 10–15% unforeseen costs.
• Check subsidy options or loans via, for example, the National Heat Fund.

Step 3: Preliminary investigation and permits

• Check whether the work is permit-free or requires an environmental permit (for example, in the case of extensions or dormers).
• Inquire with the municipality and consult the Environmental Desk.
• Have a structural or constructive investigation carried out for structural adjustments.

Step 4: Planning and drawings

• Have an architect or architectural draftsman create a design and floor plans (if necessary).
• Discuss layout, materials, installations and finishing.
• Ensure that the plans comply with the Building Decree and municipal requirements.
• Apply for an environmental permit if applicable.

Step 5: Request and compare quotes

• Request a detailed quote from at least three parties.
• Pay attention to the following components:
• Description of work
• Material and labor costs
• Planning and execution time
• Warranty periods and payment conditions
• Check references and quality marks (such as BouwGarant or KOMO).

Step 6: Planning and preparation

• Draw up a detailed work schedule together with the contractor.
• Arrange temporary facilities (e.g. water, electricity, access).
• Inform neighbors if there is nuisance or deviating working hours.
• Check insurance policies for coverage during the renovation (building, liability).

Step 7: Execution

• Let the work start according to plan and drawings.
• Hold periodic consultations with the contractor about progress and deviations.
• Document interim adjustments and approvals in writing.
• Provide daily reports or photos for larger projects.

Step 8: Completion and control

• Perform a final inspection together with the contractor upon completion.
• Note any defects or completion points in a completion report.
• Withhold 5% of the invoice amount as a deposit for completion points (if agreed).
• Request all relevant documents: warranty certificates, installation diagrams, manuals.

Step 9: Aftercare and maintenance

• Check for defects within the warranty period.
• Schedule annual maintenance for installations (e.g. central heating, ventilation, air conditioning).
• Keep all documents and invoices for warranty, insurance and resale value.

Conclusion
A renovation requires structured preparation and clear communication between all parties involved. By carefully going through the above steps you increase the chance of a technically correct, financially manageable and aesthetically successful delivery.

When renovating or expanding a home, various types of renovations are possible. The choice of the right type depends on the objective, the technical possibilities of the home, and the available budget. The overview below provides insight into the most common renovation types.

1. Internal renovation

Description: Adjustments within the existing building envelope, without expanding the living space.

Examples:

• Moving or removing interior walls
• Redesigning spaces (e.g. creating an open kitchen)
• Stair renovation or moving stairs
• Installing a new bathroom or kitchen
• Replacing floor finishes or ceilings

Characteristics:

• No permit required for load-bearing structure preservation
• Relatively short execution time
• Low to medium impact on construction

2. Structural renovation

Description: Changes to load-bearing elements of the house or fundamental structural reinforcement.

Examples:

• Removing or replacing load-bearing walls or columns
• Placing steel beams (H-profiles)
• Strengthening or replacing foundations
• Adjusting roof construction (e.g. for dormer)

Kenmerken:

• Always need architectural advice
• Permit required in many cases
• Significant impact on stability and load-bearing capacity

3. Extension

Description: Extension of the house at the back or side, often on the ground floor.

Examples:

• Extension of living room or kitchen
• Conservatory or garden room with sliding doors
• Enlarged utility room or dining room

Characteristics:

• Permit-free possible within maximum dimensions (up to 4 meters, depending on municipality)
• Foundation, floor insulation and roof construction required
• Greater impact on plot and daylight entry

4. Construction

Description: Addition of one or more floors on top of the existing house.

Examples:

• Roof construction on flat roof
• Extra floor on existing garage or extension
• Complete extra living floor on intermediate or corner house

Characteristics:

• Subject to permit
• Technical assessment of supporting structure required
• High construction and finishing costs

5. Dormer or roof extension

Description: Enlargement of usable space under the sloping roof.

Examples:

• Prefab dormer on front or back
• Custom roof structure with sliding windows
• Widening existing roof windows to facade-wide dormer

Characteristics:

• Permit-free possible when placed at the rear
• Improvement of light incidence and space utilization
• Possible influence on roof insulation and drainage

6. Garage or barn conversion

Description: Modification or integration of existing outbuildings into the main residence.

Examples:

• Converting garage into office or extra bedroom
• Conversion of barn into guest house
• Realization of practice space or hobby room

Characteristics:

• Permit depending on function and building volume
• Installation work (heating, ventilation, electricity) required
• Potential increase in property value

7. Energy-saving renovation

Description: Structural and installation-technical interventions aimed at energy efficiency.

Examples:

• Facade, floor and roof insulation
• Installing HR++ or triple glazing
• Installing heat pump, solar water heater or balanced ventilation
• Solar panels on roof or extension

Characteristics:

• Often eligible for subsidies or loans
• Sometimes require adapted structural measures
• Decrease in energy costs and increase in living comfort

8. Bathroom or kitchen renovation

Description: Replacement or renewal of the sanitary or kitchen area.

Examples:

• Complete bathroom demolition and renovation
• Installation of walk-in shower, bath, wall-mounted toilet
• New kitchen including appliances and plumbing

Features:

• Often no permit required
• Connection to existing pipes and drains required
• Possible nuisance due to demolition work and risk of water damage

Conclusion
The type of renovation largely determines the complexity, permit requirement, lead time and costs. A correct classification is necessary for a realistic planning, budgeting and risk analysis. In the case of structural or permit-required adjustments, technical advice and/or a permit is always necessary.

Not all renovations can be carried out without permission. An environmental permit is required for certain modifications. It is important to determine in advance whether your renovation plans require a permit to avoid fines, suspension or mandatory repair work.

1. When is a permit required?

In most cases, an environmental permit is required for:

• Modification of the load-bearing structure (such as removing a load-bearing wall)
• Adjustments to the facade or street side of the house
• Enlargement of the living space (e.g. extension or roof construction)
• Placement of a dormer window at the front
• Change to the appearance of a monument or protected town or village view
• Change in the use of a building (for example, from office to home)
• Placement of installations on the roof (such as heat pumps, solar panels, air conditioning units, if visible from public road)

2. When is a renovation permit-free?

A renovation is permit-free under certain conditions if:

• No load-bearing structure is modified
• It falls within the existing building (for example, moving a bathroom)
• The extension to the rear takes place and meets the maximum dimensions:
• Up to 4 meters deep (from original rear facade)
• No higher than the ground floor
• The dormer window on the rear or side of the house is placed and meets the requirements:

• Maximum 1.75 m high
• Bottom > 0.5 m and top < 0.5 m from roof edge
• Not on monuments or within protected areas

Please note: Even permit-free renovations must comply with the Building Decree and possibly with municipal aesthetic requirements.

3. How do you apply for a permit?

An environmental permit can be applied for via the Omgevingsloket (digital counter of the government). The following documents are often required for the application:

• Construction drawings or sketch designs
• Site plan and floor plans
• Structural calculation (for load-bearing elements)
• Description of the work
• Possible aesthetic advice

The processing time is in most cases 8 weeks, with a possible extension to 14 weeks for more complex applications.

4. Construction notification for works subject to notification

For some construction works (such as replacing installations or fire-resistant provisions) no permit is required, but a construction notification is necessary. This applies in particular to works that affect fire safety or structural safety in existing buildings.

5. Extra points to consider

• Monuments and protected areas have additional rules: virtually all modifications require a permit.
• Homeowners' associations and rental properties require additional permission from the owner or co-residents.
• Noise- or vibration-sensitive installations (such as heat pumps or air conditioners) must comply with noise standards.
• Municipalities may have their own policies: always check the local zoning plan and aesthetic policy.

6. Fine or enforcement in case of illegal construction

When building without a required permit, the municipality can:

• Take enforcement action with a penalty payment order or administrative enforcement order
• Impose a requirement to restore or remove the construction
• Recover liability for damage to third parties

A good permit assessment in advance prevents legal and financial risks.

Conclusion
A correct assessment of the permit requirement is essential for any renovation. If necessary, seek advice from a building specialist or an architect. This will prevent delays, extra costs and legal complications during or after the execution of the project.

A home renovation often requires a substantial investment. When personal savings are insufficient or deliberately not fully utilized, various financing options are available. Below is an overview of the most commonly used forms, including points to consider.

1. Mortgage Increase

Description:
An existing mortgage is increased or expanded with a construction deposit, based on the current property value and borrowing capacity.

Characteristics:

• Relatively low interest rate (mortgage rate)
• Repayment runs with the term of the mortgage (maximum 30 years)
• Interest is tax deductible for improvement or maintenance of own home
• Notary fees and advisory fees apply

Conditions:

• Assessment of income and property value by the lender
• Usually mandatory appraisal
• Spending accountability via invoices (for construction escrow)

2. Energy Saving Loan (National Heat Fund)

Description:
Loan for energy-saving measures on your own home, such as insulation, heat pump or HR++ glass.

Characteristics:

• Fixed low interest rate (often between 0% and 3.5%)
• Term: 7, 10, 15 or 20 years
• No closing costs
• No collateral required (so no mortgage)

Conditions:

• Only applicable to recognized measures in accordance with the Warmtefonds list
• Maximum loan amount depends on the type of measures and property

3. Personal loan

Description:
A consumer loan with a fixed term and interest rate, separate from the mortgage.

Features:

• Quick and easy to arrange
• No notary fees
• Suitable for smaller renovations (< €25,000)

Conditions:

• Higher interest rate than mortgage financing
• Term: usually 5 to 10 years
• Interest deductible if loan is demonstrably used for the own home

4. Construction deposit when buying a house

Description:
When buying a house, extra borrowing capacity can be included for future renovations, housed in a construction deposit.

Characteristics:

• Often included in the total mortgage amount
• Accountability via invoices for renovation purposes
• Temporary interest compensation on unused part

Conditions:

• Only possible at the time of purchase
• Determining for maximum loan: the value after renovation

5. Subsidies and premiums (indirect financing)

Description:
Although not a direct loan, subsidies reduce the net investment amount.

Examples:

• ISDE subsidy for insulation, heat pump, solar water heater
• Municipal loans or sustainability bonuses
• Sustainability vouchers or customized advice via municipality

6. Combinations of financing

In practice, forms of financing are often combined. For example:

• Mortgage increase for shell construction
• Energy saving loan for insulation and glass
• Subsidy for heat pump

This leads to optimal tax deduction, spread burdens and utilization of available schemes.

Overview of financing options

In 2025, various national and local subsidy schemes are available to support sustainable renovations. The emphasis is on energy saving, gas-free living and improving the energy performance of existing homes.

1. Investment Subsidy Sustainable Energy and Energy Saving (ISDE)

For whom:Homeowners, business users and Owners' Associations.

Subsidy for:

• Insulation measures (floor, roof, facade, cavity wall, glass)
• Heat pumps (air-water and hybrid systems only)
• Solar water heaters
• Connection to district heating network
• Electric cooking facilities (for gas-free renovation)

Important in 2025:

• Subsidy amounts have been increased.
• Minimum 3 m² of glass required instead of 8 m² in previous years.
• Double subsidy possible when combining two or more measures within 24 months.
• Heat pump and solar water heater also qualify without insulation measures.

Indicative amounts:

• HR++ glass: approx. €25 per m²
• Triple glass: approx. €111 per m²
• Heat pump: from €1,250 + surcharge per kW
• Solar water heater: €300 to €1,750
• District heating connection: approx. €3,775
• Electric cooking: approx. €400

2. Incentive Scheme Sustainability Sub-rental Homes (SVOH)

For whom: Private landlords.

Subsidy for:

• Heat pumps
• Solar water heaters

Characteristics:

• Aimed at landlords of one or more homes.
• Contains requirements regarding installation and housing type.

3. Incentive Scheme Natural Gas-Free Rental Housing (SAH)

For whom: Landlords and Owners' Associations.

Subsidy for:

• Connection to district heating network
• Adjustments for gas-free heating

Characteristics:

• Maximum subsidy amount per dwelling: up to €8,000
• Applies to complete dwelling disconnection from gas
• Scheme has been extended until the end of 2025

4. Local and regional regulations

For whom: Homeowners, Owners' Associations, landlords.

Subsidy and financing forms:

• Energy-saving loan via the National Heat Fund
• Municipal and provincial insulation subsidies
• Subsidies for energy advice or construction supervision
• Green loans with lower interest rates

Availability and conditions vary per municipality or province.

Overview Renovation subsidies 2025

Conclusion
The renovation subsidies in 2025 are mainly focused on sustainability. By combining measures (such as insulation with a heat pump), double subsidy is possible. Both individuals and landlords would do well to investigate in advance which national and local regulations are available for their situation.

A successful renovation stands or falls with a reliable and competent contractor. Choosing the right party requires more than just price comparison. Quality, communication, guarantees and experience are critical factors for a smooth project.

1. Determine the type of contractor needed

Depending on the scope and nature of the work, choose between:

• All-round contractor: for complete renovations including coordination of subcontractors
• Specialized trade company: for example roofing, stucco or bathroom installation
• Independent professional (zzp’er): for smaller or defined assignments
• Architect/construction supervisor: for larger projects with design, permit and supervision

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2. Request Multiple Quotes

• Preferably request at least three quotes from companies with demonstrable experience in the desired work.
• Pay attention to clarity in description, specifications, and planning.
• Check if additional work, materials, demolition, removal, and finishing are included.

Note: A low price without detailed specification is often a risk.

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3. Check Experience and References

• Ask for reference projects that are similar in scope and type.
• If possible, ask for contact details of previous clients.
• Check for the presence of a business website, portfolio, or company profile.

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4. Check Quality Marks and Registration

A reliable contractor is:

• Registered with the Chamber of Commerce
• In possession of relevant certifications or quality marks, such as:
• BouwGarant
• Techniek Nederland
• KOMO certification
• VCA (safety inspection)
• In possession of liability insurance for damage to third parties

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5. Assess communication and collaboration

Pay attention to the following in the preliminary phase:

• Speed and completeness of responses
• Willingness to think along in alternatives or cost savings
• Clarity about planning, accessibility and contact persons

Good communication in advance is often an indication for collaboration during execution.

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6. Pay attention to the warranty conditions

• Ask about the applicable warranty periods for materials and labor.
• Check whether a warranty scheme applies through a trade association.
• Discuss how service or repair will be arranged after completion.

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7. Don't choose based on price alone

• Assess the price-quality ratio: experience, materials, working method and communication are important.
• Very low offers often indicate an underestimation of the work or the use of inferior material.

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8. Record agreements in a contract

• Record all agreements in writing in a contract for services or construction contract.
• Include the following:
• Description of work
• Price agreements and payment terms
• Start and completion date
• Handling of additional and reduced work
• Guarantees and liability

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Conclusion
The best renovator is skilled, reliable, financially transparent and communicatively strong. By carefully comparing several parties and making clear agreements, you avoid misunderstandings and limit risks during the project.

 

A home renovation often requires a significant investment. With careful preparation and strategic choices, you can save considerably on material, labor, and follow-up costs. The tips below will help you manage your budget without compromising on quality.

1. Combine activities

• Have multiple activities performed simultaneously to save on call-out fees, scaffolding rental, and demolition work.
• For example, combine roof insulation with the installation of a dormer window, or floor finishing with underfloor heating.

Advantage: More efficient planning and lower total costs per component.

2. Request multiple quotes

• Compare at least three quotes from recognized contractors or installers.
• Pay attention not only to the total price, but also to specifications, planning, warranty, and additional work.

Advantage: Insight into market prices and negotiation position.

3. Perform (small) work yourself

• Simple demolition work, removal of rubble or painting can often be done yourself.
• Note that doing the work yourself does not cause warranty problems.

Advantage: Savings on labour costs of tens of euros per hour.

4. Plan outside of peak season

• Construction activity peaks in spring and summer.
• In autumn and winter, rates are often lower and availability is better.

Advantage: Shorter waiting times and lower rates from contractors.

5. Choose standard dimensions and materials

• Standard sizes for frames, doors, and tiles are often more affordable than custom sizes.
• Ask suppliers about leftover stock or showroom models.

Advantage: Lower material costs without compromising functionality.

6. Negotiate additional work

• Determine in advance what is and is not included in the price.
• Negotiate rates for possible additional work, such as extra pipes or adjustments to the hull.

Advantage: No surprises during execution.

7. Apply for available subsidies

• Check in advance whether you are eligible for national or municipal subsidies, such as the ISDE scheme or a sustainability loan.
• Combine multiple measures to receive increased subsidies.

Benefit: Direct reduction of net investment costs.

8. Opt for energy-efficient measures

• Investments in insulation, HR++ glass, a heat pump, or ventilation with heat recovery structurally reduce energy costs.
• Energy-saving measures also increase the value of the home.

Benefit: Savings on energy costs and a better selling position.

9. Have material procurement checked

• Some contractors add storage costs to material prices. Ask if you can purchase yourself or check market prices.
• Consider delivery via recognised wholesalers.

Advantage: Transparency in costs and control over quality.

10. Check insurance in advance

• Ensure that building and liability insurance also offer coverage during the renovation.
• Report larger works to your insurer in advance.

Advantage: Prevents costs in case of damage or failure.

Conclusion
Careful preparation, smart combination of tasks, and a keen eye for quotes and subsidy conditions make the difference between an expensive renovation and a financially manageable project. By contributing yourself where possible and critically assessing material choices and planning, savings of 10% to 30% are often achievable.