Excavations for an extension to an existing basement were observed at 25a High Street, Hemel Hempstead, Hertfordshire in July 2009. Most of the material removed from this extension consisted of natural chalk. A narrow pit was observed cutting into this strata but no dating evidence was retrieved. The western side of the cutting exposed the rear of an old facing wall consisting of a mix of coursed brick, flint rubble and brick and flint rubble. This is believed to be contemporary with the existing basement.