AACI Certified Commercial Real Estate Appraisals. Hammer Appraisal is a boutique real estate appraisal firm providing commercial property valuations in the Region of Durham and surrounding area. Our objective is to ensure our clients have timely, accurate and relevant valuation information to properly manage their assets, make informed decisions and mitigate risk. We offer high quality appraisal reports with a quick turn around time, by accredited AACI professionals using comprehensive market analysis to assist in managing your asset. Tangible results. Better decisions.