How to deal with purchase guarantee and a fair buyback price

Questioner

In 2012 I purchased a home with a so-called purchase guarantee provision. This states that the home was valued at 220,000 at the time. Of this, 176,600 was paid by me and 43,400 by the housing association. It was explained to me at the time that if the home increases in market value, the profit and also in the event of a loss, the difference is 70% for me and 30% for them as a housing association. All self-installed facilities (ZAV) would be attributed 100% to me upon resale. Now I am in the process of selling the house back. The house has remained almost the same in market value. However, the appointed appraiser has calculated that my ZAV is still worth €21,500. Now I have been offered €182,610 as a buyback price according to the formula: U + S + (T2-S-T1) x X% whereby U = issue price of 176,600 S = Value of effect improvements (or value of ZAV) at 21,500 T2 = appraised market value upon repurchase at 219,500 T1 = Market value at issue at 220,000 X% = Resident's share in value development at 70.4092% According to the calculation, the housing association largely allocates the ZAV to itself at a market value that is almost the same, which is not in accordance with what was explained during the sale and what they provide on the website and various brochures. As they say on the websites: 1. 'Important: The appraiser will separately appraise any facilities you have installed, such as a luxury kitchen or bathroom. The value of these facilities does not count towards the calculation of the change in value. This part of the increase in value is yours for the full 100%! Please note that the value is often lower than what the facilities cost.' (see: http://www.opmaat.nl/particulier/producten/producten-single/koopgarant.html) and 2. 'An increase in value resulting from investments by the purchaser shall be assessed separately. This part of the increase in value shall be settled 100% in the repurchase price. Developers are also obliged to apply the same rules for the distribution of value development at Koopgarant.” (see: http://www.opmaat.nl/zakelijk/producten/koopgarant/korting-en-prijsbepaling.html) How can I best address and challenge this unfair distribution of values?

Lawyer

All information made known to you that was important for the purchase of the property forms part of the purchase agreement, so you could dispute the contradiction, in which case it is useful to have evidence in the form of brochures, screenshots, etc. You must enter into negotiations, you do not have to agree to the new offer on this basis.