Decorating Park Square

Park Square was designed by John Nash as part of his comprehensive plan for Regent's Park and its surrounding terraces, conceived in 1811 and executed over the following decade. The square occupies a pivotal position in Nash's urban design, forming a transitional space between the formal curve of Park Crescent to the south and the open landscape of the park to the north. Construction of the terraces began in 1823 and was completed by 1825, with the individual houses built by speculative developers working within Nash's prescribed facade design. The square's communal garden, originally laid out by Nash's collaborator, the landscape designer Humphry Repton's successor W.A. Nesfield, was enclosed by substantial cast iron railings and planted with specimen trees and ornamental shrubs. The eastern terrace (Park Square East) has historically attracted professional and institutional occupants, while the western terrace (Park Square West) has retained a more residential character. Both ranges have undergone periodic restoration campaigns under the direction of the Crown Estate, which maintains ownership of the freehold and exercises rigorous architectural control over all external works. The square's Grade I listed status reflects its exceptional significance as one of the most complete surviving elements of Nash's Regent's Park scheme, and any conservation work must be carried out in accordance with the detailed guidance issued by Historic England for works to the highest grade of listed building.

The conservation painting of Park Square facades is governed by the Crown Estate's detailed maintenance specification, which mandates the use of silicate mineral paint systems for all lime stucco and Roman cement surfaces. Before any coating application, the existing paint system must be carefully assessed: areas of modern emulsion or acrylic masonry paint, which may have been applied during earlier, less informed maintenance campaigns, must be removed by controlled methods to restore the substrate's vapour permeability. The recommended removal technique is alkaline paste stripping under tissue poultice, followed by gentle brushing and rinsing with clean water. Where the stucco has suffered surface erosion or delamination, repair must employ a lime mortar precisely formulated to match the original, using mature lime putty aged a minimum of three years and a sharp sand aggregate of matching colour and particle size distribution. Roman cement enrichments, where eroded, should ideally be repaired with authentic Roman cement, now available from specialist suppliers who process septaria nodules according to the historical method. Where this is impractical, a carefully pigmented NHL-based repair mortar may be substituted, subject to approval by the project conservation architect. The silicate mineral paint finish should be applied in two coats, the first diluted as a primer to ensure deep penetration and optimal silicification, the second at full concentration to provide a uniform, matt finish. Colour matching must replicate the Crown Estate's approved palette, which maintains the warm cream tones that Nash specified to evoke the appearance of Bath stone. Timber sash windows, which are regularly overhauled on a cyclical programme, should be repainted using a traditional linseed oil primer and alkyd finish system. The cast iron balcony railings require cyclical de-rusting and repainting on a five-to-seven-year cycle, using a zinc phosphate primer and high-build gloss finish in black.