St James's Square, London

Project brief

Loop 360 appointed us to undertake refurbishment works to the existing rendered walls within the front courtyard at 7 St James's Square.

The project involved the careful removal of the existing render, preparation of the underlying brickwork, chasing the wall to accommodate buried services, and installation of a new render system. The scope subsequently included an extra-over provision for K Rend, following the client's instruction.

The works required careful consideration of the restricted courtyard environment, existing fixtures and fittings, access limitations and the proximity of the staircase and other building elements.

Scope of works

The project comprised the following principal works:

1. Removal of existing render

The existing render was carefully hacked off and removed from the courtyard walls. All arising waste was collected and carted away from site, leaving the underlying substrate ready for preparation.

2. Brickwork chasing for services

The existing brickwork behind the render was chased to allow services to be buried within the wall construction.

This element required coordination with the existing building fabric and careful consideration of the structural elements supporting the ground-floor walkway.

3. New sand and cement render

Following preparation of the existing surfaces, a new sand and cement render system was specified and allowed for within the original quotation.

The allowance included lightweight render mesh and approximately 20mm of Bond It Universal Building Render, or an equivalent suitable product.

4. K Rend, extra over

Following further instruction, an additional allowance was made for the use of K Rend in place of the originally specified render finish.

Technical considerations

The courtyard presented several challenges that required careful planning and workmanship.

Existing downpipes, fixtures and fittings could not always be removed to facilitate the works. Where these items remained in position, the existing render was to be neatly cut around them and the new render brought up to the existing fittings.

The staircase was also positioned close to the wall in certain locations, restricting access for conventional rendering tools. In these areas, the finish was to be completed as neatly as reasonably achievable given the restricted working space.

Two piers supporting the ground-floor walkway were identified as requiring chasing. This work was allowed for on the basis that it would be acceptable to the structural engineer, with no additional remedial works included within the quotation.

Access & logistics

Due to the location of the project within the front courtyard, logistics and material storage were important considerations.

The project assumptions included:

• Parking bay suspensions to be arranged by others to facilitate deliveries and waste collections
• Materials to be stored within the two existing vaults, or within an alternative storage area provided by the client
• Access to the client's WC for the duration of the works
• No allowance for the removal or reinstatement of existing services
• No allowance for remedial works to the underlying substrate beyond standard preparation

These provisions allowed the rendering works to be carried out efficiently while working within the constraints of the existing site.

Finish & interface works

The new render was designed to provide a durable and consistent external finish while accommodating the existing building features.

The scope specifically excluded decorative painting, which was to be undertaken by others.

The existing stone plinths and concrete soffit to the ground-floor landing were also excluded from the rendering works and were assumed to be painted separately.

A 150mm black Jack band at the base of the render was also assumed to be applied by the decorator as part of the subsequent decoration works.

Project challenges

The key challenges associated with the project included:

• Restricted access: The courtyard and proximity of the staircase created areas where access for rendering tools was limited.
• Existing fixtures and services: Downpipes and other fixtures could not always be relocated, requiring careful detailing around existing elements.
• Service integration: Chasing was required within the existing brickwork to accommodate buried services while maintaining a suitable substrate for the new render.
• Existing substrate: The new render had to be applied to an existing building fabric, with the quotation allowing for standard preparation but excluding unforeseen remedial substrate repairs.
• Site logistics: Limited storage and the requirement for parking suspensions meant that deliveries, waste removal and material storage needed to be carefully coordinated.

Project outcome

The project provided a comprehensive refurbishment solution for the rendered surfaces within the front courtyard at 7 St James's Square.

The works incorporated the removal of the existing deteriorated render, preparation of the masonry, integration of buried services and installation of a new external render finish, with the specification subsequently upgraded to include K Rend.

Particular attention was required around existing fixtures, restricted-access areas and the structural piers supporting the walkway. The works were planned around these constraints to achieve a neat and durable finish while retaining the existing features of the courtyard.