The practices won a design competition for the project, the first new construction on the site for nearly 200 years, on the south bank of the River Thames opposite the Palace of Westminster, which will house National Church Institutions of the Church of England archive.
The collection was established by Archbishop Bancroft in 1610 and contains items dating back to the 9th century including a rare vellum Gutenberg Bible dating from the early 1450s. It will be elevated to protect it from potential flooding.
Dan Pearson Studio is landscape architect for the 3850sqm plot of new landscape in the northern corner of the existing Lambeth Palace Garden, a Registered Park and Garden of Special Historic Interest Grade 11.
The practice's design includes newly proposed areas of public realm and private garden areas - which the public can view from without - a woodland edge area, a wildflower meadow, wetland glade and an extension of the existing pond into a wetland habitat, fed by rainwater collected from the new building’s roof.
Senior landscape architect Mark Rogers said: "Our landscape vision was to create a design that enhances the existing characters and ecological habitats while providing a setting in which the new and old buildings are integrated. The location of the proposed building on the existing boundary of the garden, strengthens the built fabric of the perimeter and encloses a protected landscape sanctuary which can be looked into."
The design incorporates a woodland edge with tree-filtered views, to preserve the privacy of Lambeth Palace, the residence of the Archbishop of Canterbury in London.
Rogers said that the practice had studied the existing site as a wildlife garden and the native plant communities and their habitats will guide the design of new naturalistic planting and undisturbed biodiversity.
The planting design builds on the existing parkland character, which the studio plans to keep with open grass and scattered mature trees providing filtered views to the palace.
Native trees and groundcovers will be planted alongside existing trees to form a new woodland edge to soften the building from the palace. Native hedgerow and fruiting trees provide a ‘wildlife walk’ and private access to the library. Dan Pearson Studios has opted to introduce a wildflower glade with mown paths and spaces which can be flexibly altered for the benefits of wildlife and seasonal events.
On the edge of the garden, replaced street trees, feature bollards and new natural stone paving will form a public realm area.
Rogers added: "At installation the size of planting will be varied, including a mix of trees, shrub and perennial plants sourced at different sizes from the nurseries. This will ensure a more naturalistic appearance and visual rhythm from the onset of planting through to maturity. The varying of structure will also aid establishment and favour succession, allowing more planting to be installed which can be seen to grow and develop over the first seasons."
The design also includes religiously symbolic planting which will be "subtly woven into the structure of plant communities and planting characters" Rogers said.
The practice is in the process of tendering parts of the landscape works and will use its existing list of landscape contractors. Main contractor Knight Harwood is due to start onsite next year and complete in 2020.