Answer
In the Name of Allah, Most Gracious, Most Merciful.
All praise and thanks are due to Allah, and peace and blessings be upon His Messenger.
In this fatwa:
Offering real estate valuation services is permissible regardless of the party/client asking for that service.
Answering your question, the General Iftaa’ Department in Jordan, states the following:
Real estate valuation is a permissible business since it is about offering a benefit against a wage. Moreover, a real estate valuer should be honest and trustworthy. Allah, the Almighty, said, {O you who believe! Fear God and be with those who are true (in word and deed).} (At-Tawbah 9:119)
Parties with whom the real estate valuer deals vary according to the nature of their business. It could be a bank, an organization or else.
However, the nature of those parties’ business doesn’t affect the work of a real estate valuer since, in principle, it is permissible.
In fact, he/she estimates the price of a certain real estate regardless of the party asking for that service, and this doesn’t help in committing riba (usury/interest) for Allah, the Exalted, said, {Help you one another in righteousness and piety, but help you not one another in sin and rancour: fear Allah. for Allah is strict in punishment.} (Al-Maidah 5:2) In addition, real estate valuation is a lawful job.
Accordingly, offering real estate valuation services is permissible regardless of the party/client asking for that service.
Almighty Allah knows best.
Source: http://www.aliftaa.jo