Neighbourhood street ratio determination

Municipality of Amsterdam

What is a neighbourhood street? The BSQ is determined for each neighbourhood street in Amsterdam. A neighbourhood street is that part of a street that falls into one neighbourhood. The neighbourhood classification of Research, Information and Statistics of the municipality of Amsterdam was used for this purpose. Long streets often extend over several neighbourhoods. Amsterdam has about 5,000 neighbourhood streets.

Last change on 11th of December 2025, at 15:24 (CET) | Publication Standard 1.0

• Publication category: Other algorithms
• Impact assessment: Field not filled in.
• Status: In use

General information

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Contact information

[e-mail]

Link to source registration

https://www.amsterdam.nl/wonen-leefomgeving/erfpacht/buurtstraatquote-(bsq)/

Responsible use

Goal and impact

We base ground rent costs on the land value of the property. We use the neighbourhood street ratio (BSQ) to determine the land value for existing leasehold rights with residential use. This is the percentage of the WOZ value of a property that consists of the land value. A BSQ does justice to the differences that exist in a neighbourhood.

The land value is determined by multiplying the WOZ value in the WOZ assessment of the previous tax year by the so-called neighbourhood street ratio. Different neighbourhood street ratios are used for multi-family and single-family houses.

Determining land values based on an unambiguous, objective method for the purpose of administering municipal ground lease contracts.

Calculation of individual land ratio and neighbourhood street ratio

The neighbourhood street ratio is calculated by averaging individual land ratios of single-family or multi-family houses in a neighbourhood street. The individual land ratios are determined by reducing the WOZ value by the standardised building value, thereby obtaining the individual land value. The individual land value divided by the WOZ value is the individual land ratio. Since land always represents a value, the minimum individual land ratio is set at 5% of the WOZ value. As a result, the neighbourhood street ratio is also at least 5% of the WOZ value. In addition, a maximum neighbourhood street ratio of 49% of the WOZ value is applied.

Considerations

The choice of the neighbourhood street ratio was made by the council for the following reasons:

- It is thus unnecessary to calculate the surface value for each individual leasehold right. If the building leasehold value can be calculated for a representative number of properties, the neighbourhood street ratio can be determined for the whole street. If the WOZ value is known for a property and the superficies value is not (due to a different property type or area), a land value can still be determined.

- The neighbourhood street ratio does justice to location differences. Even at very short distances, within a neighbourhood, there can be a significant difference in the level of land value. Choosing a higher scale level, e.g. calculating with neighbourhood ratios, would partially average out the value difference.

- Using a quote of the WOZ value does justice to the differences that exist between homes at the neighbourhood street level. For instance, a house with a nice view and roof terrace or a house with a garden gets a higher land value by having a higher WOZ value than the WOZ value of the houses on the mezzanines. Individual houses get a unique land value through the quote.

The methodology is consistent and transparent. The WOZ value is known to everyone and the leaseholder has been able to object to it. Similar dwelling types with similar maintenance levels have been given the same land value.

Human intervention

The BSQ is calculated by the data team of Team Advising Land Prices (TAG) part of Strategy and Advice, Land and Development.

The calculation is prepared annually independently, without the intervention of the municipality, by external researchers using the policy rules adopted by the council. The purpose of the researchers in doing so is to test whether the policy rules are being adequately implemented.

Deviations in the interpretation of policy rules (between researchers and officials) are further investigated and possible imperfections to be found are rectified, for instance by tightening the policy or changing technical assumptions. Upon joining the BSQ implementation methods and principles, the BSQ code is approved (for use in land valuation) by the external researchers.

There is thus a double check (internal: carried out by officials, and by external examiners) and assurance that the policies are properly implemented.

Risk management

Risk 1: erroneous BSQ / incorrect implementation of policies adopted by the council

Mitigating measure 1: To address this risk, BSQs are reviewed annually by external examiners.

See note under Human intervention

Combining datasets:

The BSQ algorithm is performed using linked data sources. This involves linking WOZ data with Leasehold data. Personal characteristics are removed from the datasets and are not used.

Legal basis

Adopting the Ordinance on land issuance using ground lease Amsterdam 2017. (2017, NO. 199/425)

https://zoek.officielebekendmakingen.nl/gmb-2017-140580.pdf

Elaboration on impact assessments

There can be no objection in the sense of the General Administrative Law Act because land value determination takes place in the context of a private legal act.

In the Transfer Regulation and the Land Value Policy, the municipality has ensured that the municipality applies the system of land value determination properly by having the application of the methodology of land value determination tested externally and by having a procedure for handling complaints from leaseholders regarding their

offer.

The municipality deliberately opted for a model-based method, as it is not possible to make a calculation for each individual case and this still allows a land value to be determined for almost all properties. In addition, a model-based method was chosen to create an objective and transparent system.

Non-influential parameters in the system should be excluded from objection. This concerns the WOZ value, as here the possibility of objection and appeal is already open, the housing typology and the

geographical subdivision into neighbourhood streets, as well as parameters that have been advised by an objective external party, being the superficies value.

Leaseholders only have the opportunity to raise objections on non-predefined variables. These are customised BSQ and/or unencumbered values. There are two avenues for raising reservations with Land and Development.

1). Procedure expressing reservations not private persons

Objections to the unencumbered and or customised BSQ as listed in the Transfer Offer Portal can be raised by the leaseholder at any time. As the Transfer Offer has a limited validity

has a limited validity, objections to the unencumbered value and/or bespoke BSQ as included in the Switch Offer must be submitted six weeks before the expiry of the offer.

2). Private leasehold disputes committee

From 15 September 2025, the dispute committee will handle objections from private leaseholders. A grievance can be filed if the leaseholder disagrees with the offer or an imposed penalty. The disputes committee will then assess the objections submitted.

Operations

Data

1. Hermes (leasehold data): to determine properties (objects) to be used to determine the BSQ.

2. WOZ value subcode level: to determine WOZ value, level of rebuilding costs and individual land ratios (input for BSQ determination).

3. BAG: for linking Hermes and WOZ data and for verifying address data (Hermes / WOZ).

Reconstruction cost estimates: for determining the amount of reconstruction costs per property.

Technical design

The residual land value method is based on the proposition that the revenue (WOZ value) less the costs (building value) produces the land value. The use of the BSQ to determine land value should be viewed as a standardised application of the residual land value method. Standardised because:

• standardised norms and assumptions are used and no specific assumptions are determined for each property;
• The BSQ is calculated by averaging individual land ratios of single-family or multi-family houses in a neighbourhood street. It is not based on the dwelling-specific outcomes, but on the average land ratio at the neighbourhood street or neighbourhood level.

The BSQ calculation is subject to policy frameworks and rules regarding the use of WOZ values, building values and determining the BSQ. For the purpose of the BSQ calculation, a neighbourhood ratio (BQ) is also determined. The BQ has two functions: on the one hand, it serves as a yardstick by which the 'usability/representativeness' of the BSQ is measured, and on the other hand, it serves as a substitute value if the BSQ is deemed unusable.

See the following link for an overview of the policy: https://www.amsterdam.nl/wonen-leefomgeving/erfpacht/nieuw-beleid/archief-grondprijzen/

Summary calculation method

The BSQ is calculated in accordance with the policy rules (see table above) set out in the municipal policy. Broadly speaking, the following elements and process steps are important for calculating the BSQ:

1. Generate work file: the calculation of the BSQ is done on the basis of a work file in which WOZ data, values are linked to the municipal leasehold administration (Hermes data).
2. WOZ object filter: not all objects are included in the BSQ calculation. This is subject to various criteria. Unusable or unsuitable objects are filtered out and not included in the superficies and individual land ratio determination.
3. WOZ values: it is important for the BSQ calculation that the WOZ values are available (WOZ decision issued to the interested party). The WOZ value per object serves as input for determining the individual land ratio.
4. Building-up values: for each property, the building-up value is determined using the standardised reconstruction cost estimates. The building value is calculated using the WOZ object characteristics. No data sources other than the WOZ data are used for this calculation.
5. Individual land ratios: the individual land ratio serves as input for determining the BSQ and BQ. For each property, the individual land ratio is determined using the following formula:

1. Gross BSQ and BQ: per neighbourhood street or neighbourhood, the BSQ and BQ is determined using all calculated individual land ratios.
2. BSQ criteria regarding usability, representativeness and capping limits: the gross BSQ and BQ are subjected to the policy rules and tested for representativeness, usability and also the minimum and maximum BSQ values are corrected. For each neighbourhood street, a choice is made whether the BSQ or BQ should be used. In addition, the BSQ values are also tested against minimum (5%) and maximum (49%) limits. If the minimum limit is exceeded, the BSQ is capped at 5% at the lower end, and if it is exceeded at the upper end, a capping of 49% is applied.
3. Net BSQ (BQ): the final BSQ is aggregated for each neighbourhood street and written away in an output file.

See the diagram below for an overview of the calculation method described above.

External provider

Has been developed and managed internally