how many houses are built in our a year . в прощедщем и в будущем времени.

How many houses were built in our city last year?
How many houses will be built in our city next year?

How many houses were built in our a year?
How many houses will be built in our a nex year?
Тут все легко:глаголы не меняешь.Только are меняешь (если в прошедшем на were, если в будущем на will be)