Alterations to the church involving: - Installation of air source heat pump units, heat recovery unit intake & discharge ductwork and kitchen ventilation ductwork within the existing external lightwells, - Enlargement of an existing light well with associated metalwork grillage - Installation of the boiler flue to the rear of the southern - Existing metal window frames retained and re-glazed (Type 01) - Replacement of windows at the crypt level with double glazed thermally broken steel window system (Type 02) - Alteration to the existing external stair including new metal handrail - Installation of photo-voltaic panels to the roof.