High Wycombe

Lily’s Walk

This project was one of the largest schemes of its kind ever achieved outside of the capital, featuring the Aquamodul warm blue roof with our Force Dalle BBA approved system.

Project type
New Build
Project sector
System categories
Hot Melt,
Living Roofs,
Blue Roofs
Accredited Installer
Sheriff Construction Ltd
IMG 1871 edit

Systems in use

  • Wilotekt®-Plus

    The original and industry renowned second generation hot melt system. Unique structural waterproofing designed and manufactured for use on all inverted roofs, podium decks, living roofs, blue roofs and car park decks.

  • Force Dalle®

    The first of its kind, Force Dalle is an innovative hybrid waterproofing system that combines the benefits of hot melt systems and advanced polymer modified bitumen membrane technology to create a unique and highly durable system that is a cost effective alternative to traditional hot melt.

  • Aquamodul®

    The Aquamodul blue roof sustainable drainage system is designed to attenuate, control and manage rainwater at source, providing attenuation capacity within the flat roof or podium deck construction of a development that can be combined with living roof, Solar PV and multi-functional mixed amenity finishes.

  • Extensive Living Roof

    Extensive living roofs are primarily installed to provide a visual or biodiversity interest, and are less suitable as an amenity or leisure space.


The roof attenuation rate required was 7litres/sec across the 6500m2, which is extremely low for such a large area, and the u-value of 0.10W/m2K was relatively demanding in terms of thermal performance. It was a project specific requirement that the roof was designed with falls within the slab in order to avoid any ponding water.

Lilys Walk 1 blue roof

Lilys Walk 2 roof overview


The design and implementation of a site wide blue roof ensured the development’s contribution to mitigating flood risk in the UK, supporting the protection of England’s waterways. Modelled over a 300 year period, the blue roof design is future proofed in terms of its provision for likely climate change and increases in predicted peak rainfall events.

Wilotekt-Plus, second generation hot melt structural waterproofing system, was installed as the Air and Vapour Control Layer (AVCL), which provided an extremely robust waterproof structure during the external envelope and superstructure construction phase. Hytherm ADH thermal insulation and Force Dalle bitumen membrane with anti-root technology were later installed to complete the waterproofing and insulation system.

Upon final QA inspection and integrity testing of the roof waterproofing works, the Aquamodul blue roof system, bespoke Hydrosoil Wildflower living roof and standard ballast finishes were installed in conjunction with a Solar PV array, which generated the majority of the building’s electrical energy requirements.

Blocks AB 2

Lilys Walk 3 blocks A B

You may also like to read...

Commercial & Retail — Refurbishment

Bexley Park Sports & Social Club

Systems in use: Excel® Starcoat® PMMA