If the landlord or apartment manager did know of the fact and extent of the construction at the time you signed the lease but failed to disclose that material (important) fact to you, that may consitute fraud and may give you grounds to terminate your lease without penalty. Alternately, if the construction is making your unit unhealthy to live in, that may be a violation of the implied warranty of habitability (the obligation that all rental premises be fit, or safe, for their intended purpose--in this case, residence), which violation could again provide grounds to get out of the lease or to seek monetary compensation for the time that habitability is impaired. You should speak with a landlord-tenant attorney to discuss your options.