If you purchase a good, a car, a telefone package etc and when the sale has happened under falsity or misrepresentation, that would enable you to void the contract, request money back or compensation.

Could you tell me how it is with some bigger contract like a house, a commercial lease?

I bought a commercial lease some years ago, the store room in the back and wands of the basement were always cold and dampf. Because I don't use them for trading, but only as machine room. I did not pay much attention on those condition.
Twice in strong rainy season it come to flooding of the basement. The first time I had reported to land lord, because the premise was ground floor of a building block purchased from the nearby HA. land lord's agent had advised me to contact the HA, to check the apartment above the ground floor. Waiting too long for repair, I paid for pumping water out of the basement. The second time again during strong rain season, this time floor of the machine room in the back was wet, and water flooded the basement again about 2, 3" high. I have not bothered to contact and wait for land lord's repair, I hired people to pump water out, then that was it.

Now, when renovate the store/machine room and also replacing ceiling's plaster board my builder found out there was fire damage up there, and roof was badly repaired, the consequence is over the year the roof beams were rusted through. the roof is unsafe.

Land lord will send in structural engineer in 1 or 2 weeks, until then renovation work stopped. builder will work else where. Plan we are going back to improved trading failed cause me essential financial and emotional suffering.

Now we know the floodign were cause by this fire damaged roof, do yu think, can I request reimburtment for twice I paid for pumping water out. I had no receipt because with receipt price would jump by 1/3. But land lord could get estimation how much would cost to pump 3" water out of a basement for compare anytime.

Can I request compensation or void of contract because sale was closed under falsity or misrepresentation? land lord agent is powerful over thousand of commercial premises, if they counterclaim they could easily squash me like a bug, do I have any chance. What would you do in my position?