What size single-storey extension can we add to the front of our bungalow in order to enlarge the hallway. The house is set back 25m from the highway.

Under Permitted Development (PD) rules, a single-storey extension cannot be added to the front of the house. Under the same rules, the maximum porch size is 3sqm. You will need to submit a planning application for your proposed single-storey extension. The Planning Office will make a judgement on the impact to the street scene, acknowledging that your bungalow is set back against the neighbouring properties.