What is an NWWI valuation report?

An NWWI valuation report is a property appraisal that has been validated by the NWWI (Nederlands Woning Waarde Instituut, the Netherlands Housing Value Institute). Validation means the NWWI independently checks that the appraiser and the report meet strict quality requirements before approving it. In practice, virtually every Dutch mortgage lender requires an NWWI-validated report, and it is always mandatory for an NHG mortgage.

What is the NWWI?

The NWWI was set up to give lenders, mortgage advisors and home buyers more certainty about how a home's value was determined, and to help prevent valuation fraud. The NWWI validates (approves) the reports of certified affiliated appraisers and makes sure every appraisal is drawn up in a uniform way, following clear guidelines.

Only appraisers who meet strict quality requirements can affiliate with the NWWI. Through continuous monitoring of appraisers and appraisals, the quality of an NWWI valuation is guaranteed. All appraisers work in a uniform, digital way.

Do all mortgage lenders accept NWWI validated reports?

Yes. All lenders in the Netherlands accept a valuation report validated by the NWWI, and virtually all of them now require one, especially for NHG financing. If you are taking out or increasing a mortgage on your home, you will almost certainly need an NWWI-validated report.

When do you need an NWWI appraisal report?

The WEW (administrator of the NHG) has determined that a valuation report used to finance an NHG mortgage may only be accepted if it has been validated by a recognised validation institute such as the NWWI. Validation means checking whether the appraiser and the report meet the strict quality requirements the WEW prescribes.

You will typically need an NWWI report when you:

• Take out a mortgage to buy a home
• Increase your existing mortgage (for example, to finance a renovation)
• Refinance or transfer your mortgage to another lender

Why is an NWWI appraisal report important?

A validated appraisal report is an important risk-management tool for both you and the lender. A controlled, fully substantiated appraised value protects all parties and ensures a fair appraisal.

As a buyer, the NWWI gives you insight into exactly how the value of your home was determined. The report contains an extensive substantiation and explanation by the appraiser, relevant photos of the home, and several model values that support the quality of the appraisal. The NWWI is a non-profit foundation, it does not distribute assignments and does not appraise homes itself.

What does an NWWI report cost and how long is it valid?

A validated valuation report costs roughly €500 to €900 in 2026 and usually takes about 5 to 10 working days to complete. For a mortgage application the report is typically valid for around 6 months. Read more on our page about what a property valuation costs.

NWWI validation in short

• The NWWI is non-profit and awards no assignments to appraisers
• It validates different types of valuation reports
• If a report states a predetermined desired value that conflicts with the rules, the NWWI will not pass it on to lenders
• It contributes to the prevention and detection of fraudulent valuation reports
• The appraiser works within a set working area, usually up to about 20 kilometres around your home

Ready to arrange a validated report? Compare appraisers and request a property valuation and we will match you with a certified, NWWI-affiliated appraiser.

Related articles

• What is a valuation report in the Netherlands?
• Property valuation for a mortgage
• What does a property valuation cost?
• What is the meaning of an appraiser in the Netherlands?