Clapham Park

Bauder Total Green Roof System (BTGRS) with BauderSOLAR G LIGHT


The regeneration at Clapham Park involved the demolition of old housing stock to make way for new affordable homes. The 5-storey building with 21 dwellings incorporating the latest rooftop technology which blends a biodiverse green roof and unified solar PV array. This approach met the planning requirements and maximised the limited roof space to generate energy for the residents. The development was certified BREEAM ‘Outstanding’ due to its environmental, economic and social sustainability attributes.

Bauder Building Board


Clapham Park


Clapham Park, Lambeth, London

Roof Area:

500m² green roof layered with 116m² of PV


PJMA Architects​

Approved Contractor:

EJ Roberts Ltd​

PV Installer:

M & M Electrical Ltd

The specification 

The BauderSOLAR G LIGHT system has National House Building Control (NHBC) approval and meets local authority building control (LABC) requirements. The system was installed on zero falls roof deck, making it a very cost-effective solution.

The biodiverse green roof which includes 35 plant species recognised by the RHS as Perfect for Pollinators, covers the totality of the roof area and offers a large variety of vegetation. The building reduces its carbon impact with the highly efficient PIR insulation and generates approximatively 10% of the flats usage with a maximum possible output of 75kWp from the 70 PV modules. The solar PV mounting units are ballasted by the substrate and vegetation, removing the need for any penetrating products in the waterproofing.

Products applied

Bauder Total Green Roof System
This system features a reinforced bituminous waterproofing system offering a service life expectancy in excess of 40 years.

The integration of a green roof and photovoltaics into one system drawing the maximum potential from a flat roof.

BauderGREEN Flora Seed Mixes
A blend of 49 British native species seed, to maximise diversity of vegetation on green roofs.

Project challenges

One of the major challenges of the project was the roof area, which at only 500m² needed to include a green roof and a renewable energy system to meet the main objectives of sustainability and energy efficiency of the development highlighted by the planning committee. The roof contributed towards requirements under National Planning Policy Framework (NPPF) Chapter 11: Conserving and enhancing the natural environment and The London Plan 2011 Policy 5.2 – Minimising Carbon Dioxide Emissions, Policy 5.3 – Sustainable Design and Construction and Policy 5.7 – Renewable Energy. The green roof is layered with a raised PV array so that the entire roof qualifies as a green roof whilst also providing energy generation.


System installed

Bauder Total Green Roof System (BTGRS)


1 BauderPLANT E

A torch-applied, root resistant capping sheet. The product features chemically treated bitumen to deliver superior root resistance which has been tested and approved by the FLL. The membrane is reinforced with 250g/m² spunbond polyester fleece to allow the finished product to cope with structural movement without fracture.


A self-adhesive bitumen underlayer with “DUO” lap technology to ensure thorough sealing of lap joints, even in lower temperatures. 

3 BauderPIR FA-TE

Flatboard insulation used on the lantern roof area to help meet its U-value of 0.15W/m²K. 


A self-adhesive SBS elastomeric bitumen air & vapour control layer, with a mica finished upper surface to allow easy bonding of insulation using the specified Bauder insulation adhesive.